Signed-off-by: Jeff Smith <whydo...@gmail.com>
---
 blame.c         | 1313 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 blame.h         |   11 +
 builtin/blame.c | 1318 -------------------------------------------------------
 3 files changed, 1324 insertions(+), 1318 deletions(-)

diff --git a/blame.c b/blame.c
index 8c025bc..798e61b 100644
--- a/blame.c
+++ b/blame.c
@@ -1,6 +1,9 @@
 #include "cache.h"
 #include "refs.h"
 #include "cache-tree.h"
+#include "mergesort.h"
+#include "diff.h"
+#include "diffcore.h"
 #include "blame.h"
 
 void blame_origin_decref(struct blame_origin *o)
@@ -261,3 +264,1313 @@ struct commit *fake_working_tree_commit(struct 
diff_options *opt,
 
        return commit;
 }
+
+
+
+static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
+                     xdl_emit_hunk_consume_func_t hunk_func, void *cb_data, 
int xdl_opts)
+{
+       xpparam_t xpp = {0};
+       xdemitconf_t xecfg = {0};
+       xdemitcb_t ecb = {NULL};
+
+       xpp.flags = xdl_opts;
+       xecfg.hunk_func = hunk_func;
+       ecb.priv = cb_data;
+       return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
+}
+
+/*
+ * Given an origin, prepare mmfile_t structure to be used by the
+ * diff machinery
+ */
+static void fill_origin_blob(struct diff_options *opt,
+                            struct blame_origin *o, mmfile_t *file, int 
*num_read_blob)
+{
+       if (!o->file.ptr) {
+               enum object_type type;
+               unsigned long file_size;
+
+               (*num_read_blob)++;
+               if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
+                   textconv_object(o->path, o->mode, &o->blob_oid, 1, 
&file->ptr, &file_size))
+                       ;
+               else
+                       file->ptr = read_sha1_file(o->blob_oid.hash, &type,
+                                                  &file_size);
+               file->size = file_size;
+
+               if (!file->ptr)
+                       die("Cannot read blob %s for path %s",
+                           oid_to_hex(&o->blob_oid),
+                           o->path);
+               o->file = *file;
+       }
+       else
+               *file = o->file;
+}
+
+static void drop_origin_blob(struct blame_origin *o)
+{
+       if (o->file.ptr) {
+               free(o->file.ptr);
+               o->file.ptr = NULL;
+       }
+}
+
+/*
+ * Any merge of blames happens on lists of blames that arrived via
+ * different parents in a single suspect.  In this case, we want to
+ * sort according to the suspect line numbers as opposed to the final
+ * image line numbers.  The function body is somewhat longish because
+ * it avoids unnecessary writes.
+ */
+
+static struct blame_entry *blame_merge(struct blame_entry *list1,
+                                      struct blame_entry *list2)
+{
+       struct blame_entry *p1 = list1, *p2 = list2,
+               **tail = &list1;
+
+       if (!p1)
+               return p2;
+       if (!p2)
+               return p1;
+
+       if (p1->s_lno <= p2->s_lno) {
+               do {
+                       tail = &p1->next;
+                       if ((p1 = *tail) == NULL) {
+                               *tail = p2;
+                               return list1;
+                       }
+               } while (p1->s_lno <= p2->s_lno);
+       }
+       for (;;) {
+               *tail = p2;
+               do {
+                       tail = &p2->next;
+                       if ((p2 = *tail) == NULL)  {
+                               *tail = p1;
+                               return list1;
+                       }
+               } while (p1->s_lno > p2->s_lno);
+               *tail = p1;
+               do {
+                       tail = &p1->next;
+                       if ((p1 = *tail) == NULL) {
+                               *tail = p2;
+                               return list1;
+                       }
+               } while (p1->s_lno <= p2->s_lno);
+       }
+}
+
+static void *get_next_blame(const void *p)
+{
+       return ((struct blame_entry *)p)->next;
+}
+
+static void set_next_blame(void *p1, void *p2)
+{
+       ((struct blame_entry *)p1)->next = p2;
+}
+
+/*
+ * Final image line numbers are all different, so we don't need a
+ * three-way comparison here.
+ */
+
+static int compare_blame_final(const void *p1, const void *p2)
+{
+       return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno
+               ? 1 : -1;
+}
+
+static int compare_blame_suspect(const void *p1, const void *p2)
+{
+       const struct blame_entry *s1 = p1, *s2 = p2;
+       /*
+        * to allow for collating suspects, we sort according to the
+        * respective pointer value as the primary sorting criterion.
+        * The actual relation is pretty unimportant as long as it
+        * establishes a total order.  Comparing as integers gives us
+        * that.
+        */
+       if (s1->suspect != s2->suspect)
+               return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1;
+       if (s1->s_lno == s2->s_lno)
+               return 0;
+       return s1->s_lno > s2->s_lno ? 1 : -1;
+}
+
+void blame_sort_final(struct blame_scoreboard *sb)
+{
+       sb->ent = llist_mergesort(sb->ent, get_next_blame, set_next_blame,
+                                 compare_blame_final);
+}
+
+/*
+ * For debugging -- origin is refcounted, and this asserts that
+ * we do not underflow.
+ */
+static void sanity_check_refcnt(struct blame_scoreboard *sb)
+{
+       int baa = 0;
+       struct blame_entry *ent;
+
+       for (ent = sb->ent; ent; ent = ent->next) {
+               /* Nobody should have zero or negative refcnt */
+               if (ent->suspect->refcnt <= 0) {
+                       fprintf(stderr, "%s in %s has negative refcnt %d\n",
+                               ent->suspect->path,
+                               oid_to_hex(&ent->suspect->commit->object.oid),
+                               ent->suspect->refcnt);
+                       baa = 1;
+               }
+       }
+       if (baa)
+               sb->on_sanity_fail(sb, baa);
+}
+
+/*
+ * If two blame entries that are next to each other came from
+ * contiguous lines in the same origin (i.e. <commit, path> pair),
+ * merge them together.
+ */
+void blame_coalesce(struct blame_scoreboard *sb)
+{
+       struct blame_entry *ent, *next;
+
+       for (ent = sb->ent; ent && (next = ent->next); ent = next) {
+               if (ent->suspect == next->suspect &&
+                   ent->s_lno + ent->num_lines == next->s_lno) {
+                       ent->num_lines += next->num_lines;
+                       ent->next = next->next;
+                       blame_origin_decref(next->suspect);
+                       free(next);
+                       ent->score = 0;
+                       next = ent; /* again */
+               }
+       }
+
+       if (sb->debug) /* sanity */
+               sanity_check_refcnt(sb);
+}
+
+/*
+ * Merge the given sorted list of blames into a preexisting origin.
+ * If there were no previous blames to that commit, it is entered into
+ * the commit priority queue of the score board.
+ */
+
+static void queue_blames(struct blame_scoreboard *sb, struct blame_origin 
*porigin,
+                        struct blame_entry *sorted)
+{
+       if (porigin->suspects)
+               porigin->suspects = blame_merge(porigin->suspects, sorted);
+       else {
+               struct blame_origin *o;
+               for (o = porigin->commit->util; o; o = o->next) {
+                       if (o->suspects) {
+                               porigin->suspects = sorted;
+                               return;
+                       }
+               }
+               porigin->suspects = sorted;
+               prio_queue_put(&sb->commits, porigin->commit);
+       }
+}
+
+/*
+ * We have an origin -- check if the same path exists in the
+ * parent and return an origin structure to represent it.
+ */
+static struct blame_origin *find_origin(struct commit *parent,
+                                 struct blame_origin *origin)
+{
+       struct blame_origin *porigin;
+       struct diff_options diff_opts;
+       const char *paths[2];
+
+       /* First check any existing origins */
+       for (porigin = parent->util; porigin; porigin = porigin->next)
+               if (!strcmp(porigin->path, origin->path)) {
+                       /*
+                        * The same path between origin and its parent
+                        * without renaming -- the most common case.
+                        */
+                       return blame_origin_incref (porigin);
+               }
+
+       /* See if the origin->path is different between parent
+        * and origin first.  Most of the time they are the
+        * same and diff-tree is fairly efficient about this.
+        */
+       diff_setup(&diff_opts);
+       DIFF_OPT_SET(&diff_opts, RECURSIVE);
+       diff_opts.detect_rename = 0;
+       diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+       paths[0] = origin->path;
+       paths[1] = NULL;
+
+       parse_pathspec(&diff_opts.pathspec,
+                      PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
+                      PATHSPEC_LITERAL_PATH, "", paths);
+       diff_setup_done(&diff_opts);
+
+       if (is_null_oid(&origin->commit->object.oid))
+               do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
+       else
+               diff_tree_sha1(parent->tree->object.oid.hash,
+                              origin->commit->tree->object.oid.hash,
+                              "", &diff_opts);
+       diffcore_std(&diff_opts);
+
+       if (!diff_queued_diff.nr) {
+               /* The path is the same as parent */
+               porigin = get_origin(parent, origin->path);
+               oidcpy(&porigin->blob_oid, &origin->blob_oid);
+               porigin->mode = origin->mode;
+       } else {
+               /*
+                * Since origin->path is a pathspec, if the parent
+                * commit had it as a directory, we will see a whole
+                * bunch of deletion of files in the directory that we
+                * do not care about.
+                */
+               int i;
+               struct diff_filepair *p = NULL;
+               for (i = 0; i < diff_queued_diff.nr; i++) {
+                       const char *name;
+                       p = diff_queued_diff.queue[i];
+                       name = p->one->path ? p->one->path : p->two->path;
+                       if (!strcmp(name, origin->path))
+                               break;
+               }
+               if (!p)
+                       die("internal error in blame::find_origin");
+               switch (p->status) {
+               default:
+                       die("internal error in blame::find_origin (%c)",
+                           p->status);
+               case 'M':
+                       porigin = get_origin(parent, origin->path);
+                       oidcpy(&porigin->blob_oid, &p->one->oid);
+                       porigin->mode = p->one->mode;
+                       break;
+               case 'A':
+               case 'T':
+                       /* Did not exist in parent, or type changed */
+                       break;
+               }
+       }
+       diff_flush(&diff_opts);
+       clear_pathspec(&diff_opts.pathspec);
+       return porigin;
+}
+
+/*
+ * We have an origin -- find the path that corresponds to it in its
+ * parent and return an origin structure to represent it.
+ */
+static struct blame_origin *find_rename(struct commit *parent,
+                                 struct blame_origin *origin)
+{
+       struct blame_origin *porigin = NULL;
+       struct diff_options diff_opts;
+       int i;
+
+       diff_setup(&diff_opts);
+       DIFF_OPT_SET(&diff_opts, RECURSIVE);
+       diff_opts.detect_rename = DIFF_DETECT_RENAME;
+       diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+       diff_opts.single_follow = origin->path;
+       diff_setup_done(&diff_opts);
+
+       if (is_null_oid(&origin->commit->object.oid))
+               do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
+       else
+               diff_tree_sha1(parent->tree->object.oid.hash,
+                              origin->commit->tree->object.oid.hash,
+                              "", &diff_opts);
+       diffcore_std(&diff_opts);
+
+       for (i = 0; i < diff_queued_diff.nr; i++) {
+               struct diff_filepair *p = diff_queued_diff.queue[i];
+               if ((p->status == 'R' || p->status == 'C') &&
+                   !strcmp(p->two->path, origin->path)) {
+                       porigin = get_origin(parent, p->one->path);
+                       oidcpy(&porigin->blob_oid, &p->one->oid);
+                       porigin->mode = p->one->mode;
+                       break;
+               }
+       }
+       diff_flush(&diff_opts);
+       clear_pathspec(&diff_opts.pathspec);
+       return porigin;
+}
+
+/*
+ * Append a new blame entry to a given output queue.
+ */
+static void add_blame_entry(struct blame_entry ***queue,
+                           const struct blame_entry *src)
+{
+       struct blame_entry *e = xmalloc(sizeof(*e));
+       memcpy(e, src, sizeof(*e));
+       blame_origin_incref(e->suspect);
+
+       e->next = **queue;
+       **queue = e;
+       *queue = &e->next;
+}
+
+/*
+ * src typically is on-stack; we want to copy the information in it to
+ * a malloced blame_entry that gets added to the given queue.  The
+ * origin of dst loses a refcnt.
+ */
+static void dup_entry(struct blame_entry ***queue,
+                     struct blame_entry *dst, struct blame_entry *src)
+{
+       blame_origin_incref(src->suspect);
+       blame_origin_decref(dst->suspect);
+       memcpy(dst, src, sizeof(*src));
+       dst->next = **queue;
+       **queue = dst;
+       *queue = &dst->next;
+}
+
+const char *blame_nth_line(struct blame_scoreboard *sb, long lno)
+{
+       return sb->final_buf + sb->lineno[lno];
+}
+
+/*
+ * It is known that lines between tlno to same came from parent, and e
+ * has an overlap with that range.  it also is known that parent's
+ * line plno corresponds to e's line tlno.
+ *
+ *                <---- e ----->
+ *                   <------>
+ *                   <------------>
+ *             <------------>
+ *             <------------------>
+ *
+ * Split e into potentially three parts; before this chunk, the chunk
+ * to be blamed for the parent, and after that portion.
+ */
+static void split_overlap(struct blame_entry *split,
+                         struct blame_entry *e,
+                         int tlno, int plno, int same,
+                         struct blame_origin *parent)
+{
+       int chunk_end_lno;
+       memset(split, 0, sizeof(struct blame_entry [3]));
+
+       if (e->s_lno < tlno) {
+               /* there is a pre-chunk part not blamed on parent */
+               split[0].suspect = blame_origin_incref(e->suspect);
+               split[0].lno = e->lno;
+               split[0].s_lno = e->s_lno;
+               split[0].num_lines = tlno - e->s_lno;
+               split[1].lno = e->lno + tlno - e->s_lno;
+               split[1].s_lno = plno;
+       }
+       else {
+               split[1].lno = e->lno;
+               split[1].s_lno = plno + (e->s_lno - tlno);
+       }
+
+       if (same < e->s_lno + e->num_lines) {
+               /* there is a post-chunk part not blamed on parent */
+               split[2].suspect = blame_origin_incref(e->suspect);
+               split[2].lno = e->lno + (same - e->s_lno);
+               split[2].s_lno = e->s_lno + (same - e->s_lno);
+               split[2].num_lines = e->s_lno + e->num_lines - same;
+               chunk_end_lno = split[2].lno;
+       }
+       else
+               chunk_end_lno = e->lno + e->num_lines;
+       split[1].num_lines = chunk_end_lno - split[1].lno;
+
+       /*
+        * if it turns out there is nothing to blame the parent for,
+        * forget about the splitting.  !split[1].suspect signals this.
+        */
+       if (split[1].num_lines < 1)
+               return;
+       split[1].suspect = blame_origin_incref(parent);
+}
+
+/*
+ * split_overlap() divided an existing blame e into up to three parts
+ * in split.  Any assigned blame is moved to queue to
+ * reflect the split.
+ */
+static void split_blame(struct blame_entry ***blamed,
+                       struct blame_entry ***unblamed,
+                       struct blame_entry *split,
+                       struct blame_entry *e)
+{
+       if (split[0].suspect && split[2].suspect) {
+               /* The first part (reuse storage for the existing entry e) */
+               dup_entry(unblamed, e, &split[0]);
+
+               /* The last part -- me */
+               add_blame_entry(unblamed, &split[2]);
+
+               /* ... and the middle part -- parent */
+               add_blame_entry(blamed, &split[1]);
+       }
+       else if (!split[0].suspect && !split[2].suspect)
+               /*
+                * The parent covers the entire area; reuse storage for
+                * e and replace it with the parent.
+                */
+               dup_entry(blamed, e, &split[1]);
+       else if (split[0].suspect) {
+               /* me and then parent */
+               dup_entry(unblamed, e, &split[0]);
+               add_blame_entry(blamed, &split[1]);
+       }
+       else {
+               /* parent and then me */
+               dup_entry(blamed, e, &split[1]);
+               add_blame_entry(unblamed, &split[2]);
+       }
+}
+
+/*
+ * After splitting the blame, the origins used by the
+ * on-stack blame_entry should lose one refcnt each.
+ */
+static void decref_split(struct blame_entry *split)
+{
+       int i;
+
+       for (i = 0; i < 3; i++)
+               blame_origin_decref(split[i].suspect);
+}
+
+/*
+ * reverse_blame reverses the list given in head, appending tail.
+ * That allows us to build lists in reverse order, then reverse them
+ * afterwards.  This can be faster than building the list in proper
+ * order right away.  The reason is that building in proper order
+ * requires writing a link in the _previous_ element, while building
+ * in reverse order just requires placing the list head into the
+ * _current_ element.
+ */
+
+static struct blame_entry *reverse_blame(struct blame_entry *head,
+                                        struct blame_entry *tail)
+{
+       while (head) {
+               struct blame_entry *next = head->next;
+               head->next = tail;
+               tail = head;
+               head = next;
+       }
+       return tail;
+}
+
+/*
+ * Process one hunk from the patch between the current suspect for
+ * blame_entry e and its parent.  This first blames any unfinished
+ * entries before the chunk (which is where target and parent start
+ * differing) on the parent, and then splits blame entries at the
+ * start and at the end of the difference region.  Since use of -M and
+ * -C options may lead to overlapping/duplicate source line number
+ * ranges, all we can rely on from sorting/merging is the order of the
+ * first suspect line number.
+ */
+static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq,
+                       int tlno, int offset, int same,
+                       struct blame_origin *parent)
+{
+       struct blame_entry *e = **srcq;
+       struct blame_entry *samep = NULL, *diffp = NULL;
+
+       while (e && e->s_lno < tlno) {
+               struct blame_entry *next = e->next;
+               /*
+                * current record starts before differing portion.  If
+                * it reaches into it, we need to split it up and
+                * examine the second part separately.
+                */
+               if (e->s_lno + e->num_lines > tlno) {
+                       /* Move second half to a new record */
+                       int len = tlno - e->s_lno;
+                       struct blame_entry *n = xcalloc(1, sizeof (struct 
blame_entry));
+                       n->suspect = e->suspect;
+                       n->lno = e->lno + len;
+                       n->s_lno = e->s_lno + len;
+                       n->num_lines = e->num_lines - len;
+                       e->num_lines = len;
+                       e->score = 0;
+                       /* Push new record to diffp */
+                       n->next = diffp;
+                       diffp = n;
+               } else
+                       blame_origin_decref(e->suspect);
+               /* Pass blame for everything before the differing
+                * chunk to the parent */
+               e->suspect = blame_origin_incref(parent);
+               e->s_lno += offset;
+               e->next = samep;
+               samep = e;
+               e = next;
+       }
+       /*
+        * As we don't know how much of a common stretch after this
+        * diff will occur, the currently blamed parts are all that we
+        * can assign to the parent for now.
+        */
+
+       if (samep) {
+               **dstq = reverse_blame(samep, **dstq);
+               *dstq = &samep->next;
+       }
+       /*
+        * Prepend the split off portions: everything after e starts
+        * after the blameable portion.
+        */
+       e = reverse_blame(diffp, e);
+
+       /*
+        * Now retain records on the target while parts are different
+        * from the parent.
+        */
+       samep = NULL;
+       diffp = NULL;
+       while (e && e->s_lno < same) {
+               struct blame_entry *next = e->next;
+
+               /*
+                * If current record extends into sameness, need to split.
+                */
+               if (e->s_lno + e->num_lines > same) {
+                       /*
+                        * Move second half to a new record to be
+                        * processed by later chunks
+                        */
+                       int len = same - e->s_lno;
+                       struct blame_entry *n = xcalloc(1, sizeof (struct 
blame_entry));
+                       n->suspect = blame_origin_incref(e->suspect);
+                       n->lno = e->lno + len;
+                       n->s_lno = e->s_lno + len;
+                       n->num_lines = e->num_lines - len;
+                       e->num_lines = len;
+                       e->score = 0;
+                       /* Push new record to samep */
+                       n->next = samep;
+                       samep = n;
+               }
+               e->next = diffp;
+               diffp = e;
+               e = next;
+       }
+       **srcq = reverse_blame(diffp, reverse_blame(samep, e));
+       /* Move across elements that are in the unblamable portion */
+       if (diffp)
+               *srcq = &diffp->next;
+}
+
+struct blame_chunk_cb_data {
+       struct blame_origin *parent;
+       long offset;
+       struct blame_entry **dstq;
+       struct blame_entry **srcq;
+};
+
+/* diff chunks are from parent to target */
+static int blame_chunk_cb(long start_a, long count_a,
+                         long start_b, long count_b, void *data)
+{
+       struct blame_chunk_cb_data *d = data;
+       if (start_a - start_b != d->offset)
+               die("internal error in blame::blame_chunk_cb");
+       blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b,
+                   start_b + count_b, d->parent);
+       d->offset = start_a + count_a - (start_b + count_b);
+       return 0;
+}
+
+/*
+ * We are looking at the origin 'target' and aiming to pass blame
+ * for the lines it is suspected to its parent.  Run diff to find
+ * which lines came from parent and pass blame for them.
+ */
+static void pass_blame_to_parent(struct blame_scoreboard *sb,
+                                struct blame_origin *target,
+                                struct blame_origin *parent)
+{
+       mmfile_t file_p, file_o;
+       struct blame_chunk_cb_data d;
+       struct blame_entry *newdest = NULL;
+
+       if (!target->suspects)
+               return; /* nothing remains for this target */
+
+       d.parent = parent;
+       d.offset = 0;
+       d.dstq = &newdest; d.srcq = &target->suspects;
+
+       fill_origin_blob(&sb->revs->diffopt, parent, &file_p, 
&sb->num_read_blob);
+       fill_origin_blob(&sb->revs->diffopt, target, &file_o, 
&sb->num_read_blob);
+       sb->num_get_patch++;
+
+       if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts))
+               die("unable to generate diff (%s -> %s)",
+                   oid_to_hex(&parent->commit->object.oid),
+                   oid_to_hex(&target->commit->object.oid));
+       /* The rest are the same as the parent */
+       blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, parent);
+       *d.dstq = NULL;
+       queue_blames(sb, parent, newdest);
+
+       return;
+}
+
+/*
+ * The lines in blame_entry after splitting blames many times can become
+ * very small and trivial, and at some point it becomes pointless to
+ * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
+ * ordinary C program, and it is not worth to say it was copied from
+ * totally unrelated file in the parent.
+ *
+ * Compute how trivial the lines in the blame_entry are.
+ */
+unsigned blame_entry_score(struct blame_scoreboard *sb, struct blame_entry *e)
+{
+       unsigned score;
+       const char *cp, *ep;
+
+       if (e->score)
+               return e->score;
+
+       score = 1;
+       cp = blame_nth_line(sb, e->lno);
+       ep = blame_nth_line(sb, e->lno + e->num_lines);
+       while (cp < ep) {
+               unsigned ch = *((unsigned char *)cp);
+               if (isalnum(ch))
+                       score++;
+               cp++;
+       }
+       e->score = score;
+       return score;
+}
+
+/*
+ * best_so_far[] and this[] are both a split of an existing blame_entry
+ * that passes blame to the parent.  Maintain best_so_far the best split
+ * so far, by comparing this and best_so_far and copying this into
+ * bst_so_far as needed.
+ */
+static void copy_split_if_better(struct blame_scoreboard *sb,
+                                struct blame_entry *best_so_far,
+                                struct blame_entry *this)
+{
+       int i;
+
+       if (!this[1].suspect)
+               return;
+       if (best_so_far[1].suspect) {
+               if (blame_entry_score(sb, &this[1]) < blame_entry_score(sb, 
&best_so_far[1]))
+                       return;
+       }
+
+       for (i = 0; i < 3; i++)
+               blame_origin_incref(this[i].suspect);
+       decref_split(best_so_far);
+       memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
+}
+
+/*
+ * We are looking at a part of the final image represented by
+ * ent (tlno and same are offset by ent->s_lno).
+ * tlno is where we are looking at in the final image.
+ * up to (but not including) same match preimage.
+ * plno is where we are looking at in the preimage.
+ *
+ * <-------------- final image ---------------------->
+ *       <------ent------>
+ *         ^tlno ^same
+ *    <---------preimage----->
+ *         ^plno
+ *
+ * All line numbers are 0-based.
+ */
+static void handle_split(struct blame_scoreboard *sb,
+                        struct blame_entry *ent,
+                        int tlno, int plno, int same,
+                        struct blame_origin *parent,
+                        struct blame_entry *split)
+{
+       if (ent->num_lines <= tlno)
+               return;
+       if (tlno < same) {
+               struct blame_entry this[3];
+               tlno += ent->s_lno;
+               same += ent->s_lno;
+               split_overlap(this, ent, tlno, plno, same, parent);
+               copy_split_if_better(sb, split, this);
+               decref_split(this);
+       }
+}
+
+struct handle_split_cb_data {
+       struct blame_scoreboard *sb;
+       struct blame_entry *ent;
+       struct blame_origin *parent;
+       struct blame_entry *split;
+       long plno;
+       long tlno;
+};
+
+static int handle_split_cb(long start_a, long count_a,
+                          long start_b, long count_b, void *data)
+{
+       struct handle_split_cb_data *d = data;
+       handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent,
+                    d->split);
+       d->plno = start_a + count_a;
+       d->tlno = start_b + count_b;
+       return 0;
+}
+
+/*
+ * Find the lines from parent that are the same as ent so that
+ * we can pass blames to it.  file_p has the blob contents for
+ * the parent.
+ */
+static void find_copy_in_blob(struct blame_scoreboard *sb,
+                             struct blame_entry *ent,
+                             struct blame_origin *parent,
+                             struct blame_entry *split,
+                             mmfile_t *file_p)
+{
+       const char *cp;
+       mmfile_t file_o;
+       struct handle_split_cb_data d;
+
+       memset(&d, 0, sizeof(d));
+       d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;
+       /*
+        * Prepare mmfile that contains only the lines in ent.
+        */
+       cp = blame_nth_line(sb, ent->lno);
+       file_o.ptr = (char *) cp;
+       file_o.size = blame_nth_line(sb, ent->lno + ent->num_lines) - cp;
+
+       /*
+        * file_o is a part of final image we are annotating.
+        * file_p partially may match that image.
+        */
+       memset(split, 0, sizeof(struct blame_entry [3]));
+       if (diff_hunks(file_p, &file_o, handle_split_cb, &d, sb->xdl_opts))
+               die("unable to generate diff (%s)",
+                   oid_to_hex(&parent->commit->object.oid));
+       /* remainder, if any, all match the preimage */
+       handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
+}
+
+/* Move all blame entries from list *source that have a score smaller
+ * than score_min to the front of list *small.
+ * Returns a pointer to the link pointing to the old head of the small list.
+ */
+
+static struct blame_entry **filter_small(struct blame_scoreboard *sb,
+                                        struct blame_entry **small,
+                                        struct blame_entry **source,
+                                        unsigned score_min)
+{
+       struct blame_entry *p = *source;
+       struct blame_entry *oldsmall = *small;
+       while (p) {
+               if (blame_entry_score(sb, p) <= score_min) {
+                       *small = p;
+                       small = &p->next;
+                       p = *small;
+               } else {
+                       *source = p;
+                       source = &p->next;
+                       p = *source;
+               }
+       }
+       *small = oldsmall;
+       *source = NULL;
+       return small;
+}
+
+/*
+ * See if lines currently target is suspected for can be attributed to
+ * parent.
+ */
+static void find_move_in_parent(struct blame_scoreboard *sb,
+                               struct blame_entry ***blamed,
+                               struct blame_entry **toosmall,
+                               struct blame_origin *target,
+                               struct blame_origin *parent)
+{
+       struct blame_entry *e, split[3];
+       struct blame_entry *unblamed = target->suspects;
+       struct blame_entry *leftover = NULL;
+       mmfile_t file_p;
+
+       if (!unblamed)
+               return; /* nothing remains for this target */
+
+       fill_origin_blob(&sb->revs->diffopt, parent, &file_p, 
&sb->num_read_blob);
+       if (!file_p.ptr)
+               return;
+
+       /* At each iteration, unblamed has a NULL-terminated list of
+        * entries that have not yet been tested for blame.  leftover
+        * contains the reversed list of entries that have been tested
+        * without being assignable to the parent.
+        */
+       do {
+               struct blame_entry **unblamedtail = &unblamed;
+               struct blame_entry *next;
+               for (e = unblamed; e; e = next) {
+                       next = e->next;
+                       find_copy_in_blob(sb, e, parent, split, &file_p);
+                       if (split[1].suspect &&
+                           sb->move_score < blame_entry_score(sb, &split[1])) {
+                               split_blame(blamed, &unblamedtail, split, e);
+                       } else {
+                               e->next = leftover;
+                               leftover = e;
+                       }
+                       decref_split(split);
+               }
+               *unblamedtail = NULL;
+               toosmall = filter_small(sb, toosmall, &unblamed, 
sb->move_score);
+       } while (unblamed);
+       target->suspects = reverse_blame(leftover, NULL);
+}
+
+struct blame_list {
+       struct blame_entry *ent;
+       struct blame_entry split[3];
+};
+
+/*
+ * Count the number of entries the target is suspected for,
+ * and prepare a list of entry and the best split.
+ */
+static struct blame_list *setup_blame_list(struct blame_entry *unblamed,
+                                          int *num_ents_p)
+{
+       struct blame_entry *e;
+       int num_ents, i;
+       struct blame_list *blame_list = NULL;
+
+       for (e = unblamed, num_ents = 0; e; e = e->next)
+               num_ents++;
+       if (num_ents) {
+               blame_list = xcalloc(num_ents, sizeof(struct blame_list));
+               for (e = unblamed, i = 0; e; e = e->next)
+                       blame_list[i++].ent = e;
+       }
+       *num_ents_p = num_ents;
+       return blame_list;
+}
+
+/*
+ * For lines target is suspected for, see if we can find code movement
+ * across file boundary from the parent commit.  porigin is the path
+ * in the parent we already tried.
+ */
+static void find_copy_in_parent(struct blame_scoreboard *sb,
+                               struct blame_entry ***blamed,
+                               struct blame_entry **toosmall,
+                               struct blame_origin *target,
+                               struct commit *parent,
+                               struct blame_origin *porigin,
+                               int opt)
+{
+       struct diff_options diff_opts;
+       int i, j;
+       struct blame_list *blame_list;
+       int num_ents;
+       struct blame_entry *unblamed = target->suspects;
+       struct blame_entry *leftover = NULL;
+
+       if (!unblamed)
+               return; /* nothing remains for this target */
+
+       diff_setup(&diff_opts);
+       DIFF_OPT_SET(&diff_opts, RECURSIVE);
+       diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+
+       diff_setup_done(&diff_opts);
+
+       /* Try "find copies harder" on new path if requested;
+        * we do not want to use diffcore_rename() actually to
+        * match things up; find_copies_harder is set only to
+        * force diff_tree_sha1() to feed all filepairs to diff_queue,
+        * and this code needs to be after diff_setup_done(), which
+        * usually makes find-copies-harder imply copy detection.
+        */
+       if ((opt & PICKAXE_BLAME_COPY_HARDEST)
+           || ((opt & PICKAXE_BLAME_COPY_HARDER)
+               && (!porigin || strcmp(target->path, porigin->path))))
+               DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
+
+       if (is_null_oid(&target->commit->object.oid))
+               do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
+       else
+               diff_tree_sha1(parent->tree->object.oid.hash,
+                              target->commit->tree->object.oid.hash,
+                              "", &diff_opts);
+
+       if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
+               diffcore_std(&diff_opts);
+
+       do {
+               struct blame_entry **unblamedtail = &unblamed;
+               blame_list = setup_blame_list(unblamed, &num_ents);
+
+               for (i = 0; i < diff_queued_diff.nr; i++) {
+                       struct diff_filepair *p = diff_queued_diff.queue[i];
+                       struct blame_origin *norigin;
+                       mmfile_t file_p;
+                       struct blame_entry this[3];
+
+                       if (!DIFF_FILE_VALID(p->one))
+                               continue; /* does not exist in parent */
+                       if (S_ISGITLINK(p->one->mode))
+                               continue; /* ignore git links */
+                       if (porigin && !strcmp(p->one->path, porigin->path))
+                               /* find_move already dealt with this path */
+                               continue;
+
+                       norigin = get_origin(parent, p->one->path);
+                       oidcpy(&norigin->blob_oid, &p->one->oid);
+                       norigin->mode = p->one->mode;
+                       fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, 
&sb->num_read_blob);
+                       if (!file_p.ptr)
+                               continue;
+
+                       for (j = 0; j < num_ents; j++) {
+                               find_copy_in_blob(sb, blame_list[j].ent,
+                                                 norigin, this, &file_p);
+                               copy_split_if_better(sb, blame_list[j].split,
+                                                    this);
+                               decref_split(this);
+                       }
+                       blame_origin_decref(norigin);
+               }
+
+               for (j = 0; j < num_ents; j++) {
+                       struct blame_entry *split = blame_list[j].split;
+                       if (split[1].suspect &&
+                           sb->copy_score < blame_entry_score(sb, &split[1])) {
+                               split_blame(blamed, &unblamedtail, split,
+                                           blame_list[j].ent);
+                       } else {
+                               blame_list[j].ent->next = leftover;
+                               leftover = blame_list[j].ent;
+                       }
+                       decref_split(split);
+               }
+               free(blame_list);
+               *unblamedtail = NULL;
+               toosmall = filter_small(sb, toosmall, &unblamed, 
sb->copy_score);
+       } while (unblamed);
+       target->suspects = reverse_blame(leftover, NULL);
+       diff_flush(&diff_opts);
+       clear_pathspec(&diff_opts.pathspec);
+}
+
+/*
+ * The blobs of origin and porigin exactly match, so everything
+ * origin is suspected for can be blamed on the parent.
+ */
+static void pass_whole_blame(struct blame_scoreboard *sb,
+                            struct blame_origin *origin, struct blame_origin 
*porigin)
+{
+       struct blame_entry *e, *suspects;
+
+       if (!porigin->file.ptr && origin->file.ptr) {
+               /* Steal its file */
+               porigin->file = origin->file;
+               origin->file.ptr = NULL;
+       }
+       suspects = origin->suspects;
+       origin->suspects = NULL;
+       for (e = suspects; e; e = e->next) {
+               blame_origin_incref(porigin);
+               blame_origin_decref(e->suspect);
+               e->suspect = porigin;
+       }
+       queue_blames(sb, porigin, suspects);
+}
+
+/*
+ * We pass blame from the current commit to its parents.  We keep saying
+ * "parent" (and "porigin"), but what we mean is to find scapegoat to
+ * exonerate ourselves.
+ */
+static struct commit_list *first_scapegoat(struct rev_info *revs, struct 
commit *commit,
+                                       int reverse)
+{
+       if (!reverse) {
+               if (revs->first_parent_only &&
+                   commit->parents &&
+                   commit->parents->next) {
+                       free_commit_list(commit->parents->next);
+                       commit->parents->next = NULL;
+               }
+               return commit->parents;
+       }
+       return lookup_decoration(&revs->children, &commit->object);
+}
+
+static int num_scapegoats(struct rev_info *revs, struct commit *commit, int 
reverse)
+{
+       struct commit_list *l = first_scapegoat(revs, commit, reverse);
+       return commit_list_count(l);
+}
+
+/* Distribute collected unsorted blames to the respected sorted lists
+ * in the various origins.
+ */
+static void distribute_blame(struct blame_scoreboard *sb, struct blame_entry 
*blamed)
+{
+       blamed = llist_mergesort(blamed, get_next_blame, set_next_blame,
+                                compare_blame_suspect);
+       while (blamed)
+       {
+               struct blame_origin *porigin = blamed->suspect;
+               struct blame_entry *suspects = NULL;
+               do {
+                       struct blame_entry *next = blamed->next;
+                       blamed->next = suspects;
+                       suspects = blamed;
+                       blamed = next;
+               } while (blamed && blamed->suspect == porigin);
+               suspects = reverse_blame(suspects, NULL);
+               queue_blames(sb, porigin, suspects);
+       }
+}
+
+#define MAXSG 16
+
+static void pass_blame(struct blame_scoreboard *sb, struct blame_origin 
*origin, int opt)
+{
+       struct rev_info *revs = sb->revs;
+       int i, pass, num_sg;
+       struct commit *commit = origin->commit;
+       struct commit_list *sg;
+       struct blame_origin *sg_buf[MAXSG];
+       struct blame_origin *porigin, **sg_origin = sg_buf;
+       struct blame_entry *toosmall = NULL;
+       struct blame_entry *blames, **blametail = &blames;
+
+       num_sg = num_scapegoats(revs, commit, sb->reverse);
+       if (!num_sg)
+               goto finish;
+       else if (num_sg < ARRAY_SIZE(sg_buf))
+               memset(sg_buf, 0, sizeof(sg_buf));
+       else
+               sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
+
+       /*
+        * The first pass looks for unrenamed path to optimize for
+        * common cases, then we look for renames in the second pass.
+        */
+       for (pass = 0; pass < 2 - sb->no_whole_file_rename; pass++) {
+               struct blame_origin *(*find)(struct commit *, struct 
blame_origin *);
+               find = pass ? find_rename : find_origin;
+
+               for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
+                    i < num_sg && sg;
+                    sg = sg->next, i++) {
+                       struct commit *p = sg->item;
+                       int j, same;
+
+                       if (sg_origin[i])
+                               continue;
+                       if (parse_commit(p))
+                               continue;
+                       porigin = find(p, origin);
+                       if (!porigin)
+                               continue;
+                       if (!oidcmp(&porigin->blob_oid, &origin->blob_oid)) {
+                               pass_whole_blame(sb, origin, porigin);
+                               blame_origin_decref(porigin);
+                               goto finish;
+                       }
+                       for (j = same = 0; j < i; j++)
+                               if (sg_origin[j] &&
+                                   !oidcmp(&sg_origin[j]->blob_oid, 
&porigin->blob_oid)) {
+                                       same = 1;
+                                       break;
+                               }
+                       if (!same)
+                               sg_origin[i] = porigin;
+                       else
+                               blame_origin_decref(porigin);
+               }
+       }
+
+       sb->num_commits++;
+       for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
+            i < num_sg && sg;
+            sg = sg->next, i++) {
+               struct blame_origin *porigin = sg_origin[i];
+               if (!porigin)
+                       continue;
+               if (!origin->previous) {
+                       blame_origin_incref(porigin);
+                       origin->previous = porigin;
+               }
+               pass_blame_to_parent(sb, origin, porigin);
+               if (!origin->suspects)
+                       goto finish;
+       }
+
+       /*
+        * Optionally find moves in parents' files.
+        */
+       if (opt & PICKAXE_BLAME_MOVE) {
+               filter_small(sb, &toosmall, &origin->suspects, sb->move_score);
+               if (origin->suspects) {
+                       for (i = 0, sg = first_scapegoat(revs, commit, 
sb->reverse);
+                            i < num_sg && sg;
+                            sg = sg->next, i++) {
+                               struct blame_origin *porigin = sg_origin[i];
+                               if (!porigin)
+                                       continue;
+                               find_move_in_parent(sb, &blametail, &toosmall, 
origin, porigin);
+                               if (!origin->suspects)
+                                       break;
+                       }
+               }
+       }
+
+       /*
+        * Optionally find copies from parents' files.
+        */
+       if (opt & PICKAXE_BLAME_COPY) {
+               if (sb->copy_score > sb->move_score)
+                       filter_small(sb, &toosmall, &origin->suspects, 
sb->copy_score);
+               else if (sb->copy_score < sb->move_score) {
+                       origin->suspects = blame_merge(origin->suspects, 
toosmall);
+                       toosmall = NULL;
+                       filter_small(sb, &toosmall, &origin->suspects, 
sb->copy_score);
+               }
+               if (!origin->suspects)
+                       goto finish;
+
+               for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
+                    i < num_sg && sg;
+                    sg = sg->next, i++) {
+                       struct blame_origin *porigin = sg_origin[i];
+                       find_copy_in_parent(sb, &blametail, &toosmall,
+                                           origin, sg->item, porigin, opt);
+                       if (!origin->suspects)
+                               goto finish;
+               }
+       }
+
+finish:
+       *blametail = NULL;
+       distribute_blame(sb, blames);
+       /*
+        * prepend toosmall to origin->suspects
+        *
+        * There is no point in sorting: this ends up on a big
+        * unsorted list in the caller anyway.
+        */
+       if (toosmall) {
+               struct blame_entry **tail = &toosmall;
+               while (*tail)
+                       tail = &(*tail)->next;
+               *tail = origin->suspects;
+               origin->suspects = toosmall;
+       }
+       for (i = 0; i < num_sg; i++) {
+               if (sg_origin[i]) {
+                       drop_origin_blob(sg_origin[i]);
+                       blame_origin_decref(sg_origin[i]);
+               }
+       }
+       drop_origin_blob(origin);
+       if (sg_buf != sg_origin)
+               free(sg_origin);
+}
+
+/*
+ * The main loop -- while we have blobs with lines whose true origin
+ * is still unknown, pick one blob, and allow its lines to pass blames
+ * to its parents. */
+void assign_blame(struct blame_scoreboard *sb, int opt)
+{
+       struct rev_info *revs = sb->revs;
+       struct commit *commit = prio_queue_get(&sb->commits);
+
+       while (commit) {
+               struct blame_entry *ent;
+               struct blame_origin *suspect = commit->util;
+
+               /* find one suspect to break down */
+               while (suspect && !suspect->suspects)
+                       suspect = suspect->next;
+
+               if (!suspect) {
+                       commit = prio_queue_get(&sb->commits);
+                       continue;
+               }
+
+               assert(commit == suspect->commit);
+
+               /*
+                * We will use this suspect later in the loop,
+                * so hold onto it in the meantime.
+                */
+               blame_origin_incref(suspect);
+               parse_commit(commit);
+               if (sb->reverse ||
+                   (!(commit->object.flags & UNINTERESTING) &&
+                    !(revs->max_age != -1 && commit->date < revs->max_age)))
+                       pass_blame(sb, suspect, opt);
+               else {
+                       commit->object.flags |= UNINTERESTING;
+                       if (commit->object.parsed)
+                               mark_parents_uninteresting(commit);
+               }
+               /* treat root commit as boundary */
+               if (!commit->parents && !sb->show_root)
+                       commit->object.flags |= UNINTERESTING;
+
+               /* Take responsibility for the remaining entries */
+               ent = suspect->suspects;
+               if (ent) {
+                       suspect->guilty = 1;
+                       for (;;) {
+                               struct blame_entry *next = ent->next;
+                               if (sb->found_guilty_entry)
+                                       sb->found_guilty_entry(ent, 
sb->found_guilty_entry_data);
+                               if (next) {
+                                       ent = next;
+                                       continue;
+                               }
+                               ent->next = sb->ent;
+                               sb->ent = suspect->suspects;
+                               suspect->suspects = NULL;
+                               break;
+                       }
+               }
+               blame_origin_decref(suspect);
+
+               if (sb->debug) /* sanity */
+                       sanity_check_refcnt(sb);
+       }
+}
diff --git a/blame.h b/blame.h
index 0d10e17..df824b2 100644
--- a/blame.h
+++ b/blame.h
@@ -8,6 +8,11 @@
 #include "prio-queue.h"
 #include "diff.h"
 
+#define PICKAXE_BLAME_MOVE             01
+#define PICKAXE_BLAME_COPY             02
+#define PICKAXE_BLAME_COPY_HARDER      04
+#define PICKAXE_BLAME_COPY_HARDEST     010
+
 /*
  * One blob in a commit that is being suspected
  */
@@ -157,4 +162,10 @@ extern struct blame_origin *get_origin(struct commit 
*commit, const char *path);
 
 extern struct commit *fake_working_tree_commit(struct diff_options *opt, const 
char *path, const char *contents_from);
 
+extern void blame_coalesce(struct blame_scoreboard *sb);
+extern void blame_sort_final(struct blame_scoreboard *sb);
+extern unsigned blame_entry_score(struct blame_scoreboard *sb, struct 
blame_entry *e);
+extern void assign_blame(struct blame_scoreboard *sb, int opt);
+extern const char *blame_nth_line(struct blame_scoreboard *sb, long lno);
+
 #endif /* BLAME_H */
diff --git a/builtin/blame.c b/builtin/blame.c
index 3679214..461506c 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -12,13 +12,10 @@
 #include "tag.h"
 #include "tree-walk.h"
 #include "diff.h"
-#include "diffcore.h"
 #include "revision.h"
 #include "quote.h"
-#include "xdiff-interface.h"
 #include "string-list.h"
 #include "mailmap.h"
-#include "mergesort.h"
 #include "parse-options.h"
 #include "prio-queue.h"
 #include "utf8.h"
@@ -61,11 +58,6 @@ static struct string_list mailmap = STRING_LIST_INIT_NODUP;
 #define DEBUG 0
 #endif
 
-#define PICKAXE_BLAME_MOVE             01
-#define PICKAXE_BLAME_COPY             02
-#define PICKAXE_BLAME_COPY_HARDER      04
-#define PICKAXE_BLAME_COPY_HARDEST     010
-
 static unsigned blame_move_score;
 static unsigned blame_copy_score;
 #define BLAME_DEFAULT_MOVE_SCORE       20
@@ -80,143 +72,6 @@ struct progress_info {
        int blamed_lines;
 };
 
-static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
-                     xdl_emit_hunk_consume_func_t hunk_func, void *cb_data, 
int xdl_opts)
-{
-       xpparam_t xpp = {0};
-       xdemitconf_t xecfg = {0};
-       xdemitcb_t ecb = {NULL};
-
-       xpp.flags = xdl_opts;
-       xecfg.hunk_func = hunk_func;
-       ecb.priv = cb_data;
-       return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
-}
-
-/*
- * Given an origin, prepare mmfile_t structure to be used by the
- * diff machinery
- */
-static void fill_origin_blob(struct diff_options *opt,
-                            struct blame_origin *o, mmfile_t *file, int 
*num_read_blob)
-{
-       if (!o->file.ptr) {
-               enum object_type type;
-               unsigned long file_size;
-
-               (*num_read_blob)++;
-               if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
-                   textconv_object(o->path, o->mode, &o->blob_oid, 1, 
&file->ptr, &file_size))
-                       ;
-               else
-                       file->ptr = read_sha1_file(o->blob_oid.hash, &type,
-                                                  &file_size);
-               file->size = file_size;
-
-               if (!file->ptr)
-                       die("Cannot read blob %s for path %s",
-                           oid_to_hex(&o->blob_oid),
-                           o->path);
-               o->file = *file;
-       }
-       else
-               *file = o->file;
-}
-
-static void drop_origin_blob(struct blame_origin *o)
-{
-       if (o->file.ptr) {
-               free(o->file.ptr);
-               o->file.ptr = NULL;
-       }
-}
-
-/*
- * Any merge of blames happens on lists of blames that arrived via
- * different parents in a single suspect.  In this case, we want to
- * sort according to the suspect line numbers as opposed to the final
- * image line numbers.  The function body is somewhat longish because
- * it avoids unnecessary writes.
- */
-
-static struct blame_entry *blame_merge(struct blame_entry *list1,
-                                      struct blame_entry *list2)
-{
-       struct blame_entry *p1 = list1, *p2 = list2,
-               **tail = &list1;
-
-       if (!p1)
-               return p2;
-       if (!p2)
-               return p1;
-
-       if (p1->s_lno <= p2->s_lno) {
-               do {
-                       tail = &p1->next;
-                       if ((p1 = *tail) == NULL) {
-                               *tail = p2;
-                               return list1;
-                       }
-               } while (p1->s_lno <= p2->s_lno);
-       }
-       for (;;) {
-               *tail = p2;
-               do {
-                       tail = &p2->next;
-                       if ((p2 = *tail) == NULL)  {
-                               *tail = p1;
-                               return list1;
-                       }
-               } while (p1->s_lno > p2->s_lno);
-               *tail = p1;
-               do {
-                       tail = &p1->next;
-                       if ((p1 = *tail) == NULL) {
-                               *tail = p2;
-                               return list1;
-                       }
-               } while (p1->s_lno <= p2->s_lno);
-       }
-}
-
-static void *get_next_blame(const void *p)
-{
-       return ((struct blame_entry *)p)->next;
-}
-
-static void set_next_blame(void *p1, void *p2)
-{
-       ((struct blame_entry *)p1)->next = p2;
-}
-
-/*
- * Final image line numbers are all different, so we don't need a
- * three-way comparison here.
- */
-
-static int compare_blame_final(const void *p1, const void *p2)
-{
-       return ((struct blame_entry *)p1)->lno > ((struct blame_entry *)p2)->lno
-               ? 1 : -1;
-}
-
-static int compare_blame_suspect(const void *p1, const void *p2)
-{
-       const struct blame_entry *s1 = p1, *s2 = p2;
-       /*
-        * to allow for collating suspects, we sort according to the
-        * respective pointer value as the primary sorting criterion.
-        * The actual relation is pretty unimportant as long as it
-        * establishes a total order.  Comparing as integers gives us
-        * that.
-        */
-       if (s1->suspect != s2->suspect)
-               return (intptr_t)s1->suspect > (intptr_t)s2->suspect ? 1 : -1;
-       if (s1->s_lno == s2->s_lno)
-               return 0;
-       return s1->s_lno > s2->s_lno ? 1 : -1;
-}
-
 static int compare_commits_by_reverse_commit_date(const void *a,
                                                  const void *b,
                                                  void *c)
@@ -224,63 +79,6 @@ static int compare_commits_by_reverse_commit_date(const 
void *a,
        return -compare_commits_by_commit_date(a, b, c);
 }
 
-static void blame_sort_final(struct blame_scoreboard *sb)
-{
-       sb->ent = llist_mergesort(sb->ent, get_next_blame, set_next_blame,
-                                 compare_blame_final);
-}
-
-static void sanity_check_refcnt(struct blame_scoreboard *);
-
-/*
- * If two blame entries that are next to each other came from
- * contiguous lines in the same origin (i.e. <commit, path> pair),
- * merge them together.
- */
-static void blame_coalesce(struct blame_scoreboard *sb)
-{
-       struct blame_entry *ent, *next;
-
-       for (ent = sb->ent; ent && (next = ent->next); ent = next) {
-               if (ent->suspect == next->suspect &&
-                   ent->s_lno + ent->num_lines == next->s_lno) {
-                       ent->num_lines += next->num_lines;
-                       ent->next = next->next;
-                       blame_origin_decref(next->suspect);
-                       free(next);
-                       ent->score = 0;
-                       next = ent; /* again */
-               }
-       }
-
-       if (sb->debug) /* sanity */
-               sanity_check_refcnt(sb);
-}
-
-/*
- * Merge the given sorted list of blames into a preexisting origin.
- * If there were no previous blames to that commit, it is entered into
- * the commit priority queue of the score board.
- */
-
-static void queue_blames(struct blame_scoreboard *sb, struct blame_origin 
*porigin,
-                        struct blame_entry *sorted)
-{
-       if (porigin->suspects)
-               porigin->suspects = blame_merge(porigin->suspects, sorted);
-       else {
-               struct blame_origin *o;
-               for (o = porigin->commit->util; o; o = o->next) {
-                       if (o->suspects) {
-                               porigin->suspects = sorted;
-                               return;
-                       }
-               }
-               porigin->suspects = sorted;
-               prio_queue_put(&sb->commits, porigin->commit);
-       }
-}
-
 /*
  * Fill the blob_sha1 field of an origin if it hasn't, so that later
  * call to fill_origin_blob() can use it to locate the data.  blob_sha1
@@ -307,1037 +105,12 @@ static int fill_blob_sha1_and_mode(struct blame_origin 
*origin)
        return -1;
 }
 
-/*
- * We have an origin -- check if the same path exists in the
- * parent and return an origin structure to represent it.
- */
-static struct blame_origin *find_origin(struct commit *parent,
-                                 struct blame_origin *origin)
-{
-       struct blame_origin *porigin;
-       struct diff_options diff_opts;
-       const char *paths[2];
-
-       /* First check any existing origins */
-       for (porigin = parent->util; porigin; porigin = porigin->next)
-               if (!strcmp(porigin->path, origin->path)) {
-                       /*
-                        * The same path between origin and its parent
-                        * without renaming -- the most common case.
-                        */
-                       return blame_origin_incref (porigin);
-               }
-
-       /* See if the origin->path is different between parent
-        * and origin first.  Most of the time they are the
-        * same and diff-tree is fairly efficient about this.
-        */
-       diff_setup(&diff_opts);
-       DIFF_OPT_SET(&diff_opts, RECURSIVE);
-       diff_opts.detect_rename = 0;
-       diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
-       paths[0] = origin->path;
-       paths[1] = NULL;
-
-       parse_pathspec(&diff_opts.pathspec,
-                      PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
-                      PATHSPEC_LITERAL_PATH, "", paths);
-       diff_setup_done(&diff_opts);
-
-       if (is_null_oid(&origin->commit->object.oid))
-               do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
-       else
-               diff_tree_sha1(parent->tree->object.oid.hash,
-                              origin->commit->tree->object.oid.hash,
-                              "", &diff_opts);
-       diffcore_std(&diff_opts);
-
-       if (!diff_queued_diff.nr) {
-               /* The path is the same as parent */
-               porigin = get_origin(parent, origin->path);
-               oidcpy(&porigin->blob_oid, &origin->blob_oid);
-               porigin->mode = origin->mode;
-       } else {
-               /*
-                * Since origin->path is a pathspec, if the parent
-                * commit had it as a directory, we will see a whole
-                * bunch of deletion of files in the directory that we
-                * do not care about.
-                */
-               int i;
-               struct diff_filepair *p = NULL;
-               for (i = 0; i < diff_queued_diff.nr; i++) {
-                       const char *name;
-                       p = diff_queued_diff.queue[i];
-                       name = p->one->path ? p->one->path : p->two->path;
-                       if (!strcmp(name, origin->path))
-                               break;
-               }
-               if (!p)
-                       die("internal error in blame::find_origin");
-               switch (p->status) {
-               default:
-                       die("internal error in blame::find_origin (%c)",
-                           p->status);
-               case 'M':
-                       porigin = get_origin(parent, origin->path);
-                       oidcpy(&porigin->blob_oid, &p->one->oid);
-                       porigin->mode = p->one->mode;
-                       break;
-               case 'A':
-               case 'T':
-                       /* Did not exist in parent, or type changed */
-                       break;
-               }
-       }
-       diff_flush(&diff_opts);
-       clear_pathspec(&diff_opts.pathspec);
-       return porigin;
-}
-
-/*
- * We have an origin -- find the path that corresponds to it in its
- * parent and return an origin structure to represent it.
- */
-static struct blame_origin *find_rename(struct commit *parent,
-                                 struct blame_origin *origin)
-{
-       struct blame_origin *porigin = NULL;
-       struct diff_options diff_opts;
-       int i;
-
-       diff_setup(&diff_opts);
-       DIFF_OPT_SET(&diff_opts, RECURSIVE);
-       diff_opts.detect_rename = DIFF_DETECT_RENAME;
-       diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
-       diff_opts.single_follow = origin->path;
-       diff_setup_done(&diff_opts);
-
-       if (is_null_oid(&origin->commit->object.oid))
-               do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
-       else
-               diff_tree_sha1(parent->tree->object.oid.hash,
-                              origin->commit->tree->object.oid.hash,
-                              "", &diff_opts);
-       diffcore_std(&diff_opts);
-
-       for (i = 0; i < diff_queued_diff.nr; i++) {
-               struct diff_filepair *p = diff_queued_diff.queue[i];
-               if ((p->status == 'R' || p->status == 'C') &&
-                   !strcmp(p->two->path, origin->path)) {
-                       porigin = get_origin(parent, p->one->path);
-                       oidcpy(&porigin->blob_oid, &p->one->oid);
-                       porigin->mode = p->one->mode;
-                       break;
-               }
-       }
-       diff_flush(&diff_opts);
-       clear_pathspec(&diff_opts.pathspec);
-       return porigin;
-}
-
-/*
- * Append a new blame entry to a given output queue.
- */
-static void add_blame_entry(struct blame_entry ***queue,
-                           const struct blame_entry *src)
-{
-       struct blame_entry *e = xmalloc(sizeof(*e));
-       memcpy(e, src, sizeof(*e));
-       blame_origin_incref(e->suspect);
-
-       e->next = **queue;
-       **queue = e;
-       *queue = &e->next;
-}
-
-/*
- * src typically is on-stack; we want to copy the information in it to
- * a malloced blame_entry that gets added to the given queue.  The
- * origin of dst loses a refcnt.
- */
-static void dup_entry(struct blame_entry ***queue,
-                     struct blame_entry *dst, struct blame_entry *src)
-{
-       blame_origin_incref(src->suspect);
-       blame_origin_decref(dst->suspect);
-       memcpy(dst, src, sizeof(*src));
-       dst->next = **queue;
-       **queue = dst;
-       *queue = &dst->next;
-}
-
-static const char *blame_nth_line(struct blame_scoreboard *sb, long lno)
-{
-       return sb->final_buf + sb->lineno[lno];
-}
-
 static const char *nth_line_cb(void *data, long lno)
 {
        return blame_nth_line((struct blame_scoreboard *)data, lno);
 }
 
 /*
- * It is known that lines between tlno to same came from parent, and e
- * has an overlap with that range.  it also is known that parent's
- * line plno corresponds to e's line tlno.
- *
- *                <---- e ----->
- *                   <------>
- *                   <------------>
- *             <------------>
- *             <------------------>
- *
- * Split e into potentially three parts; before this chunk, the chunk
- * to be blamed for the parent, and after that portion.
- */
-static void split_overlap(struct blame_entry *split,
-                         struct blame_entry *e,
-                         int tlno, int plno, int same,
-                         struct blame_origin *parent)
-{
-       int chunk_end_lno;
-       memset(split, 0, sizeof(struct blame_entry [3]));
-
-       if (e->s_lno < tlno) {
-               /* there is a pre-chunk part not blamed on parent */
-               split[0].suspect = blame_origin_incref(e->suspect);
-               split[0].lno = e->lno;
-               split[0].s_lno = e->s_lno;
-               split[0].num_lines = tlno - e->s_lno;
-               split[1].lno = e->lno + tlno - e->s_lno;
-               split[1].s_lno = plno;
-       }
-       else {
-               split[1].lno = e->lno;
-               split[1].s_lno = plno + (e->s_lno - tlno);
-       }
-
-       if (same < e->s_lno + e->num_lines) {
-               /* there is a post-chunk part not blamed on parent */
-               split[2].suspect = blame_origin_incref(e->suspect);
-               split[2].lno = e->lno + (same - e->s_lno);
-               split[2].s_lno = e->s_lno + (same - e->s_lno);
-               split[2].num_lines = e->s_lno + e->num_lines - same;
-               chunk_end_lno = split[2].lno;
-       }
-       else
-               chunk_end_lno = e->lno + e->num_lines;
-       split[1].num_lines = chunk_end_lno - split[1].lno;
-
-       /*
-        * if it turns out there is nothing to blame the parent for,
-        * forget about the splitting.  !split[1].suspect signals this.
-        */
-       if (split[1].num_lines < 1)
-               return;
-       split[1].suspect = blame_origin_incref(parent);
-}
-
-/*
- * split_overlap() divided an existing blame e into up to three parts
- * in split.  Any assigned blame is moved to queue to
- * reflect the split.
- */
-static void split_blame(struct blame_entry ***blamed,
-                       struct blame_entry ***unblamed,
-                       struct blame_entry *split,
-                       struct blame_entry *e)
-{
-       if (split[0].suspect && split[2].suspect) {
-               /* The first part (reuse storage for the existing entry e) */
-               dup_entry(unblamed, e, &split[0]);
-
-               /* The last part -- me */
-               add_blame_entry(unblamed, &split[2]);
-
-               /* ... and the middle part -- parent */
-               add_blame_entry(blamed, &split[1]);
-       }
-       else if (!split[0].suspect && !split[2].suspect)
-               /*
-                * The parent covers the entire area; reuse storage for
-                * e and replace it with the parent.
-                */
-               dup_entry(blamed, e, &split[1]);
-       else if (split[0].suspect) {
-               /* me and then parent */
-               dup_entry(unblamed, e, &split[0]);
-               add_blame_entry(blamed, &split[1]);
-       }
-       else {
-               /* parent and then me */
-               dup_entry(blamed, e, &split[1]);
-               add_blame_entry(unblamed, &split[2]);
-       }
-}
-
-/*
- * After splitting the blame, the origins used by the
- * on-stack blame_entry should lose one refcnt each.
- */
-static void decref_split(struct blame_entry *split)
-{
-       int i;
-
-       for (i = 0; i < 3; i++)
-               blame_origin_decref(split[i].suspect);
-}
-
-/*
- * reverse_blame reverses the list given in head, appending tail.
- * That allows us to build lists in reverse order, then reverse them
- * afterwards.  This can be faster than building the list in proper
- * order right away.  The reason is that building in proper order
- * requires writing a link in the _previous_ element, while building
- * in reverse order just requires placing the list head into the
- * _current_ element.
- */
-
-static struct blame_entry *reverse_blame(struct blame_entry *head,
-                                        struct blame_entry *tail)
-{
-       while (head) {
-               struct blame_entry *next = head->next;
-               head->next = tail;
-               tail = head;
-               head = next;
-       }
-       return tail;
-}
-
-/*
- * Process one hunk from the patch between the current suspect for
- * blame_entry e and its parent.  This first blames any unfinished
- * entries before the chunk (which is where target and parent start
- * differing) on the parent, and then splits blame entries at the
- * start and at the end of the difference region.  Since use of -M and
- * -C options may lead to overlapping/duplicate source line number
- * ranges, all we can rely on from sorting/merging is the order of the
- * first suspect line number.
- */
-static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq,
-                       int tlno, int offset, int same,
-                       struct blame_origin *parent)
-{
-       struct blame_entry *e = **srcq;
-       struct blame_entry *samep = NULL, *diffp = NULL;
-
-       while (e && e->s_lno < tlno) {
-               struct blame_entry *next = e->next;
-               /*
-                * current record starts before differing portion.  If
-                * it reaches into it, we need to split it up and
-                * examine the second part separately.
-                */
-               if (e->s_lno + e->num_lines > tlno) {
-                       /* Move second half to a new record */
-                       int len = tlno - e->s_lno;
-                       struct blame_entry *n = xcalloc(1, sizeof (struct 
blame_entry));
-                       n->suspect = e->suspect;
-                       n->lno = e->lno + len;
-                       n->s_lno = e->s_lno + len;
-                       n->num_lines = e->num_lines - len;
-                       e->num_lines = len;
-                       e->score = 0;
-                       /* Push new record to diffp */
-                       n->next = diffp;
-                       diffp = n;
-               } else
-                       blame_origin_decref(e->suspect);
-               /* Pass blame for everything before the differing
-                * chunk to the parent */
-               e->suspect = blame_origin_incref(parent);
-               e->s_lno += offset;
-               e->next = samep;
-               samep = e;
-               e = next;
-       }
-       /*
-        * As we don't know how much of a common stretch after this
-        * diff will occur, the currently blamed parts are all that we
-        * can assign to the parent for now.
-        */
-
-       if (samep) {
-               **dstq = reverse_blame(samep, **dstq);
-               *dstq = &samep->next;
-       }
-       /*
-        * Prepend the split off portions: everything after e starts
-        * after the blameable portion.
-        */
-       e = reverse_blame(diffp, e);
-
-       /*
-        * Now retain records on the target while parts are different
-        * from the parent.
-        */
-       samep = NULL;
-       diffp = NULL;
-       while (e && e->s_lno < same) {
-               struct blame_entry *next = e->next;
-
-               /*
-                * If current record extends into sameness, need to split.
-                */
-               if (e->s_lno + e->num_lines > same) {
-                       /*
-                        * Move second half to a new record to be
-                        * processed by later chunks
-                        */
-                       int len = same - e->s_lno;
-                       struct blame_entry *n = xcalloc(1, sizeof (struct 
blame_entry));
-                       n->suspect = blame_origin_incref(e->suspect);
-                       n->lno = e->lno + len;
-                       n->s_lno = e->s_lno + len;
-                       n->num_lines = e->num_lines - len;
-                       e->num_lines = len;
-                       e->score = 0;
-                       /* Push new record to samep */
-                       n->next = samep;
-                       samep = n;
-               }
-               e->next = diffp;
-               diffp = e;
-               e = next;
-       }
-       **srcq = reverse_blame(diffp, reverse_blame(samep, e));
-       /* Move across elements that are in the unblamable portion */
-       if (diffp)
-               *srcq = &diffp->next;
-}
-
-struct blame_chunk_cb_data {
-       struct blame_origin *parent;
-       long offset;
-       struct blame_entry **dstq;
-       struct blame_entry **srcq;
-};
-
-/* diff chunks are from parent to target */
-static int blame_chunk_cb(long start_a, long count_a,
-                         long start_b, long count_b, void *data)
-{
-       struct blame_chunk_cb_data *d = data;
-       if (start_a - start_b != d->offset)
-               die("internal error in blame::blame_chunk_cb");
-       blame_chunk(&d->dstq, &d->srcq, start_b, start_a - start_b,
-                   start_b + count_b, d->parent);
-       d->offset = start_a + count_a - (start_b + count_b);
-       return 0;
-}
-
-/*
- * We are looking at the origin 'target' and aiming to pass blame
- * for the lines it is suspected to its parent.  Run diff to find
- * which lines came from parent and pass blame for them.
- */
-static void pass_blame_to_parent(struct blame_scoreboard *sb,
-                                struct blame_origin *target,
-                                struct blame_origin *parent)
-{
-       mmfile_t file_p, file_o;
-       struct blame_chunk_cb_data d;
-       struct blame_entry *newdest = NULL;
-
-       if (!target->suspects)
-               return; /* nothing remains for this target */
-
-       d.parent = parent;
-       d.offset = 0;
-       d.dstq = &newdest; d.srcq = &target->suspects;
-
-       fill_origin_blob(&sb->revs->diffopt, parent, &file_p, 
&sb->num_read_blob);
-       fill_origin_blob(&sb->revs->diffopt, target, &file_o, 
&sb->num_read_blob);
-       sb->num_get_patch++;
-
-       if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, sb->xdl_opts))
-               die("unable to generate diff (%s -> %s)",
-                   oid_to_hex(&parent->commit->object.oid),
-                   oid_to_hex(&target->commit->object.oid));
-       /* The rest are the same as the parent */
-       blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, parent);
-       *d.dstq = NULL;
-       queue_blames(sb, parent, newdest);
-
-       return;
-}
-
-/*
- * The lines in blame_entry after splitting blames many times can become
- * very small and trivial, and at some point it becomes pointless to
- * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
- * ordinary C program, and it is not worth to say it was copied from
- * totally unrelated file in the parent.
- *
- * Compute how trivial the lines in the blame_entry are.
- */
-static unsigned blame_entry_score(struct blame_scoreboard *sb, struct 
blame_entry *e)
-{
-       unsigned score;
-       const char *cp, *ep;
-
-       if (e->score)
-               return e->score;
-
-       score = 1;
-       cp = blame_nth_line(sb, e->lno);
-       ep = blame_nth_line(sb, e->lno + e->num_lines);
-       while (cp < ep) {
-               unsigned ch = *((unsigned char *)cp);
-               if (isalnum(ch))
-                       score++;
-               cp++;
-       }
-       e->score = score;
-       return score;
-}
-
-/*
- * best_so_far[] and this[] are both a split of an existing blame_entry
- * that passes blame to the parent.  Maintain best_so_far the best split
- * so far, by comparing this and best_so_far and copying this into
- * bst_so_far as needed.
- */
-static void copy_split_if_better(struct blame_scoreboard *sb,
-                                struct blame_entry *best_so_far,
-                                struct blame_entry *this)
-{
-       int i;
-
-       if (!this[1].suspect)
-               return;
-       if (best_so_far[1].suspect) {
-               if (blame_entry_score(sb, &this[1]) < blame_entry_score(sb, 
&best_so_far[1]))
-                       return;
-       }
-
-       for (i = 0; i < 3; i++)
-               blame_origin_incref(this[i].suspect);
-       decref_split(best_so_far);
-       memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
-}
-
-/*
- * We are looking at a part of the final image represented by
- * ent (tlno and same are offset by ent->s_lno).
- * tlno is where we are looking at in the final image.
- * up to (but not including) same match preimage.
- * plno is where we are looking at in the preimage.
- *
- * <-------------- final image ---------------------->
- *       <------ent------>
- *         ^tlno ^same
- *    <---------preimage----->
- *         ^plno
- *
- * All line numbers are 0-based.
- */
-static void handle_split(struct blame_scoreboard *sb,
-                        struct blame_entry *ent,
-                        int tlno, int plno, int same,
-                        struct blame_origin *parent,
-                        struct blame_entry *split)
-{
-       if (ent->num_lines <= tlno)
-               return;
-       if (tlno < same) {
-               struct blame_entry this[3];
-               tlno += ent->s_lno;
-               same += ent->s_lno;
-               split_overlap(this, ent, tlno, plno, same, parent);
-               copy_split_if_better(sb, split, this);
-               decref_split(this);
-       }
-}
-
-struct handle_split_cb_data {
-       struct blame_scoreboard *sb;
-       struct blame_entry *ent;
-       struct blame_origin *parent;
-       struct blame_entry *split;
-       long plno;
-       long tlno;
-};
-
-static int handle_split_cb(long start_a, long count_a,
-                          long start_b, long count_b, void *data)
-{
-       struct handle_split_cb_data *d = data;
-       handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent,
-                    d->split);
-       d->plno = start_a + count_a;
-       d->tlno = start_b + count_b;
-       return 0;
-}
-
-/*
- * Find the lines from parent that are the same as ent so that
- * we can pass blames to it.  file_p has the blob contents for
- * the parent.
- */
-static void find_copy_in_blob(struct blame_scoreboard *sb,
-                             struct blame_entry *ent,
-                             struct blame_origin *parent,
-                             struct blame_entry *split,
-                             mmfile_t *file_p)
-{
-       const char *cp;
-       mmfile_t file_o;
-       struct handle_split_cb_data d;
-
-       memset(&d, 0, sizeof(d));
-       d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;
-       /*
-        * Prepare mmfile that contains only the lines in ent.
-        */
-       cp = blame_nth_line(sb, ent->lno);
-       file_o.ptr = (char *) cp;
-       file_o.size = blame_nth_line(sb, ent->lno + ent->num_lines) - cp;
-
-       /*
-        * file_o is a part of final image we are annotating.
-        * file_p partially may match that image.
-        */
-       memset(split, 0, sizeof(struct blame_entry [3]));
-       if (diff_hunks(file_p, &file_o, handle_split_cb, &d, sb->xdl_opts))
-               die("unable to generate diff (%s)",
-                   oid_to_hex(&parent->commit->object.oid));
-       /* remainder, if any, all match the preimage */
-       handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
-}
-
-/* Move all blame entries from list *source that have a score smaller
- * than score_min to the front of list *small.
- * Returns a pointer to the link pointing to the old head of the small list.
- */
-
-static struct blame_entry **filter_small(struct blame_scoreboard *sb,
-                                        struct blame_entry **small,
-                                        struct blame_entry **source,
-                                        unsigned score_min)
-{
-       struct blame_entry *p = *source;
-       struct blame_entry *oldsmall = *small;
-       while (p) {
-               if (blame_entry_score(sb, p) <= score_min) {
-                       *small = p;
-                       small = &p->next;
-                       p = *small;
-               } else {
-                       *source = p;
-                       source = &p->next;
-                       p = *source;
-               }
-       }
-       *small = oldsmall;
-       *source = NULL;
-       return small;
-}
-
-/*
- * See if lines currently target is suspected for can be attributed to
- * parent.
- */
-static void find_move_in_parent(struct blame_scoreboard *sb,
-                               struct blame_entry ***blamed,
-                               struct blame_entry **toosmall,
-                               struct blame_origin *target,
-                               struct blame_origin *parent)
-{
-       struct blame_entry *e, split[3];
-       struct blame_entry *unblamed = target->suspects;
-       struct blame_entry *leftover = NULL;
-       mmfile_t file_p;
-
-       if (!unblamed)
-               return; /* nothing remains for this target */
-
-       fill_origin_blob(&sb->revs->diffopt, parent, &file_p, 
&sb->num_read_blob);
-       if (!file_p.ptr)
-               return;
-
-       /* At each iteration, unblamed has a NULL-terminated list of
-        * entries that have not yet been tested for blame.  leftover
-        * contains the reversed list of entries that have been tested
-        * without being assignable to the parent.
-        */
-       do {
-               struct blame_entry **unblamedtail = &unblamed;
-               struct blame_entry *next;
-               for (e = unblamed; e; e = next) {
-                       next = e->next;
-                       find_copy_in_blob(sb, e, parent, split, &file_p);
-                       if (split[1].suspect &&
-                           sb->move_score < blame_entry_score(sb, &split[1])) {
-                               split_blame(blamed, &unblamedtail, split, e);
-                       } else {
-                               e->next = leftover;
-                               leftover = e;
-                       }
-                       decref_split(split);
-               }
-               *unblamedtail = NULL;
-               toosmall = filter_small(sb, toosmall, &unblamed, 
sb->move_score);
-       } while (unblamed);
-       target->suspects = reverse_blame(leftover, NULL);
-}
-
-struct blame_list {
-       struct blame_entry *ent;
-       struct blame_entry split[3];
-};
-
-/*
- * Count the number of entries the target is suspected for,
- * and prepare a list of entry and the best split.
- */
-static struct blame_list *setup_blame_list(struct blame_entry *unblamed,
-                                          int *num_ents_p)
-{
-       struct blame_entry *e;
-       int num_ents, i;
-       struct blame_list *blame_list = NULL;
-
-       for (e = unblamed, num_ents = 0; e; e = e->next)
-               num_ents++;
-       if (num_ents) {
-               blame_list = xcalloc(num_ents, sizeof(struct blame_list));
-               for (e = unblamed, i = 0; e; e = e->next)
-                       blame_list[i++].ent = e;
-       }
-       *num_ents_p = num_ents;
-       return blame_list;
-}
-
-/*
- * For lines target is suspected for, see if we can find code movement
- * across file boundary from the parent commit.  porigin is the path
- * in the parent we already tried.
- */
-static void find_copy_in_parent(struct blame_scoreboard *sb,
-                               struct blame_entry ***blamed,
-                               struct blame_entry **toosmall,
-                               struct blame_origin *target,
-                               struct commit *parent,
-                               struct blame_origin *porigin,
-                               int opt)
-{
-       struct diff_options diff_opts;
-       int i, j;
-       struct blame_list *blame_list;
-       int num_ents;
-       struct blame_entry *unblamed = target->suspects;
-       struct blame_entry *leftover = NULL;
-
-       if (!unblamed)
-               return; /* nothing remains for this target */
-
-       diff_setup(&diff_opts);
-       DIFF_OPT_SET(&diff_opts, RECURSIVE);
-       diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
-
-       diff_setup_done(&diff_opts);
-
-       /* Try "find copies harder" on new path if requested;
-        * we do not want to use diffcore_rename() actually to
-        * match things up; find_copies_harder is set only to
-        * force diff_tree_sha1() to feed all filepairs to diff_queue,
-        * and this code needs to be after diff_setup_done(), which
-        * usually makes find-copies-harder imply copy detection.
-        */
-       if ((opt & PICKAXE_BLAME_COPY_HARDEST)
-           || ((opt & PICKAXE_BLAME_COPY_HARDER)
-               && (!porigin || strcmp(target->path, porigin->path))))
-               DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
-
-       if (is_null_oid(&target->commit->object.oid))
-               do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
-       else
-               diff_tree_sha1(parent->tree->object.oid.hash,
-                              target->commit->tree->object.oid.hash,
-                              "", &diff_opts);
-
-       if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
-               diffcore_std(&diff_opts);
-
-       do {
-               struct blame_entry **unblamedtail = &unblamed;
-               blame_list = setup_blame_list(unblamed, &num_ents);
-
-               for (i = 0; i < diff_queued_diff.nr; i++) {
-                       struct diff_filepair *p = diff_queued_diff.queue[i];
-                       struct blame_origin *norigin;
-                       mmfile_t file_p;
-                       struct blame_entry this[3];
-
-                       if (!DIFF_FILE_VALID(p->one))
-                               continue; /* does not exist in parent */
-                       if (S_ISGITLINK(p->one->mode))
-                               continue; /* ignore git links */
-                       if (porigin && !strcmp(p->one->path, porigin->path))
-                               /* find_move already dealt with this path */
-                               continue;
-
-                       norigin = get_origin(parent, p->one->path);
-                       oidcpy(&norigin->blob_oid, &p->one->oid);
-                       norigin->mode = p->one->mode;
-                       fill_origin_blob(&sb->revs->diffopt, norigin, &file_p, 
&sb->num_read_blob);
-                       if (!file_p.ptr)
-                               continue;
-
-                       for (j = 0; j < num_ents; j++) {
-                               find_copy_in_blob(sb, blame_list[j].ent,
-                                                 norigin, this, &file_p);
-                               copy_split_if_better(sb, blame_list[j].split,
-                                                    this);
-                               decref_split(this);
-                       }
-                       blame_origin_decref(norigin);
-               }
-
-               for (j = 0; j < num_ents; j++) {
-                       struct blame_entry *split = blame_list[j].split;
-                       if (split[1].suspect &&
-                           sb->copy_score < blame_entry_score(sb, &split[1])) {
-                               split_blame(blamed, &unblamedtail, split,
-                                           blame_list[j].ent);
-                       } else {
-                               blame_list[j].ent->next = leftover;
-                               leftover = blame_list[j].ent;
-                       }
-                       decref_split(split);
-               }
-               free(blame_list);
-               *unblamedtail = NULL;
-               toosmall = filter_small(sb, toosmall, &unblamed, 
sb->copy_score);
-       } while (unblamed);
-       target->suspects = reverse_blame(leftover, NULL);
-       diff_flush(&diff_opts);
-       clear_pathspec(&diff_opts.pathspec);
-}
-
-/*
- * The blobs of origin and porigin exactly match, so everything
- * origin is suspected for can be blamed on the parent.
- */
-static void pass_whole_blame(struct blame_scoreboard *sb,
-                            struct blame_origin *origin, struct blame_origin 
*porigin)
-{
-       struct blame_entry *e, *suspects;
-
-       if (!porigin->file.ptr && origin->file.ptr) {
-               /* Steal its file */
-               porigin->file = origin->file;
-               origin->file.ptr = NULL;
-       }
-       suspects = origin->suspects;
-       origin->suspects = NULL;
-       for (e = suspects; e; e = e->next) {
-               blame_origin_incref(porigin);
-               blame_origin_decref(e->suspect);
-               e->suspect = porigin;
-       }
-       queue_blames(sb, porigin, suspects);
-}
-
-/*
- * We pass blame from the current commit to its parents.  We keep saying
- * "parent" (and "porigin"), but what we mean is to find scapegoat to
- * exonerate ourselves.
- */
-static struct commit_list *first_scapegoat(struct rev_info *revs, struct 
commit *commit,
-                                          int reverse)
-{
-       if (!reverse) {
-               if (revs->first_parent_only &&
-                   commit->parents &&
-                   commit->parents->next) {
-                       free_commit_list(commit->parents->next);
-                       commit->parents->next = NULL;
-               }
-               return commit->parents;
-       }
-       return lookup_decoration(&revs->children, &commit->object);
-}
-
-static int num_scapegoats(struct rev_info *revs, struct commit *commit, int 
reverse)
-{
-       struct commit_list *l = first_scapegoat(revs, commit, reverse);
-       return commit_list_count(l);
-}
-
-/* Distribute collected unsorted blames to the respected sorted lists
- * in the various origins.
- */
-static void distribute_blame(struct blame_scoreboard *sb, struct blame_entry 
*blamed)
-{
-       blamed = llist_mergesort(blamed, get_next_blame, set_next_blame,
-                                compare_blame_suspect);
-       while (blamed)
-       {
-               struct blame_origin *porigin = blamed->suspect;
-               struct blame_entry *suspects = NULL;
-               do {
-                       struct blame_entry *next = blamed->next;
-                       blamed->next = suspects;
-                       suspects = blamed;
-                       blamed = next;
-               } while (blamed && blamed->suspect == porigin);
-               suspects = reverse_blame(suspects, NULL);
-               queue_blames(sb, porigin, suspects);
-       }
-}
-
-#define MAXSG 16
-
-static void pass_blame(struct blame_scoreboard *sb, struct blame_origin 
*origin, int opt)
-{
-       struct rev_info *revs = sb->revs;
-       int i, pass, num_sg;
-       struct commit *commit = origin->commit;
-       struct commit_list *sg;
-       struct blame_origin *sg_buf[MAXSG];
-       struct blame_origin *porigin, **sg_origin = sg_buf;
-       struct blame_entry *toosmall = NULL;
-       struct blame_entry *blames, **blametail = &blames;
-
-       num_sg = num_scapegoats(revs, commit, sb->reverse);
-       if (!num_sg)
-               goto finish;
-       else if (num_sg < ARRAY_SIZE(sg_buf))
-               memset(sg_buf, 0, sizeof(sg_buf));
-       else
-               sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
-
-       /*
-        * The first pass looks for unrenamed path to optimize for
-        * common cases, then we look for renames in the second pass.
-        */
-       for (pass = 0; pass < 2 - sb->no_whole_file_rename; pass++) {
-               struct blame_origin *(*find)(struct commit *, struct 
blame_origin *);
-               find = pass ? find_rename : find_origin;
-
-               for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
-                    i < num_sg && sg;
-                    sg = sg->next, i++) {
-                       struct commit *p = sg->item;
-                       int j, same;
-
-                       if (sg_origin[i])
-                               continue;
-                       if (parse_commit(p))
-                               continue;
-                       porigin = find(p, origin);
-                       if (!porigin)
-                               continue;
-                       if (!oidcmp(&porigin->blob_oid, &origin->blob_oid)) {
-                               pass_whole_blame(sb, origin, porigin);
-                               blame_origin_decref(porigin);
-                               goto finish;
-                       }
-                       for (j = same = 0; j < i; j++)
-                               if (sg_origin[j] &&
-                                   !oidcmp(&sg_origin[j]->blob_oid, 
&porigin->blob_oid)) {
-                                       same = 1;
-                                       break;
-                               }
-                       if (!same)
-                               sg_origin[i] = porigin;
-                       else
-                               blame_origin_decref(porigin);
-               }
-       }
-
-       sb->num_commits++;
-       for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
-            i < num_sg && sg;
-            sg = sg->next, i++) {
-               struct blame_origin *porigin = sg_origin[i];
-               if (!porigin)
-                       continue;
-               if (!origin->previous) {
-                       blame_origin_incref(porigin);
-                       origin->previous = porigin;
-               }
-               pass_blame_to_parent(sb, origin, porigin);
-               if (!origin->suspects)
-                       goto finish;
-       }
-
-       /*
-        * Optionally find moves in parents' files.
-        */
-       if (opt & PICKAXE_BLAME_MOVE) {
-               filter_small(sb, &toosmall, &origin->suspects, sb->move_score);
-               if (origin->suspects) {
-                       for (i = 0, sg = first_scapegoat(revs, commit, 
sb->reverse);
-                            i < num_sg && sg;
-                            sg = sg->next, i++) {
-                               struct blame_origin *porigin = sg_origin[i];
-                               if (!porigin)
-                                       continue;
-                               find_move_in_parent(sb, &blametail, &toosmall, 
origin, porigin);
-                               if (!origin->suspects)
-                                       break;
-                       }
-               }
-       }
-
-       /*
-        * Optionally find copies from parents' files.
-        */
-       if (opt & PICKAXE_BLAME_COPY) {
-               if (sb->copy_score > sb->move_score)
-                       filter_small(sb, &toosmall, &origin->suspects, 
sb->copy_score);
-               else if (sb->copy_score < sb->move_score) {
-                       origin->suspects = blame_merge(origin->suspects, 
toosmall);
-                       toosmall = NULL;
-                       filter_small(sb, &toosmall, &origin->suspects, 
sb->copy_score);
-               }
-               if (!origin->suspects)
-                       goto finish;
-
-               for (i = 0, sg = first_scapegoat(revs, commit, sb->reverse);
-                    i < num_sg && sg;
-                    sg = sg->next, i++) {
-                       struct blame_origin *porigin = sg_origin[i];
-                       find_copy_in_parent(sb, &blametail, &toosmall,
-                                           origin, sg->item, porigin, opt);
-                       if (!origin->suspects)
-                               goto finish;
-               }
-       }
-
-finish:
-       *blametail = NULL;
-       distribute_blame(sb, blames);
-       /*
-        * prepend toosmall to origin->suspects
-        *
-        * There is no point in sorting: this ends up on a big
-        * unsorted list in the caller anyway.
-        */
-       if (toosmall) {
-               struct blame_entry **tail = &toosmall;
-               while (*tail)
-                       tail = &(*tail)->next;
-               *tail = origin->suspects;
-               origin->suspects = toosmall;
-       }
-       for (i = 0; i < num_sg; i++) {
-               if (sg_origin[i]) {
-                       drop_origin_blob(sg_origin[i]);
-                       blame_origin_decref(sg_origin[i]);
-               }
-       }
-       drop_origin_blob(origin);
-       if (sg_buf != sg_origin)
-               free(sg_origin);
-}
-
-/*
  * Information on commits, used for output.
  */
 struct commit_info {
@@ -1546,74 +319,6 @@ static void found_guilty_entry(struct blame_entry *ent, 
void *data)
        display_progress(pi->progress, pi->blamed_lines);
 }
 
-/*
- * The main loop -- while we have blobs with lines whose true origin
- * is still unknown, pick one blob, and allow its lines to pass blames
- * to its parents. */
-static void assign_blame(struct blame_scoreboard *sb, int opt)
-{
-       struct rev_info *revs = sb->revs;
-       struct commit *commit = prio_queue_get(&sb->commits);
-
-       while (commit) {
-               struct blame_entry *ent;
-               struct blame_origin *suspect = commit->util;
-
-               /* find one suspect to break down */
-               while (suspect && !suspect->suspects)
-                       suspect = suspect->next;
-
-               if (!suspect) {
-                       commit = prio_queue_get(&sb->commits);
-                       continue;
-               }
-
-               assert(commit == suspect->commit);
-
-               /*
-                * We will use this suspect later in the loop,
-                * so hold onto it in the meantime.
-                */
-               blame_origin_incref(suspect);
-               parse_commit(commit);
-               if (sb->reverse ||
-                   (!(commit->object.flags & UNINTERESTING) &&
-                    !(revs->max_age != -1 && commit->date < revs->max_age)))
-                       pass_blame(sb, suspect, opt);
-               else {
-                       commit->object.flags |= UNINTERESTING;
-                       if (commit->object.parsed)
-                               mark_parents_uninteresting(commit);
-               }
-               /* treat root commit as boundary */
-               if (!commit->parents && !sb->show_root)
-                       commit->object.flags |= UNINTERESTING;
-
-               /* Take responsibility for the remaining entries */
-               ent = suspect->suspects;
-               if (ent) {
-                       suspect->guilty = 1;
-                       for (;;) {
-                               struct blame_entry *next = ent->next;
-                               if (sb->found_guilty_entry)
-                                       sb->found_guilty_entry(ent, 
sb->found_guilty_entry_data);
-                               if (next) {
-                                       ent = next;
-                                       continue;
-                               }
-                               ent->next = sb->ent;
-                               sb->ent = suspect->suspects;
-                               suspect->suspects = NULL;
-                               break;
-                       }
-               }
-               blame_origin_decref(suspect);
-
-               if (sb->debug) /* sanity */
-                       sanity_check_refcnt(sb);
-       }
-}
-
 static const char *format_time(timestamp_t time, const char *tz_str,
                               int show_raw_time)
 {
@@ -1927,29 +632,6 @@ static void find_alignment(struct blame_scoreboard *sb, 
int *option)
                abbrev = auto_abbrev + 1;
 }
 
-/*
- * For debugging -- origin is refcounted, and this asserts that
- * we do not underflow.
- */
-static void sanity_check_refcnt(struct blame_scoreboard *sb)
-{
-       int baa = 0;
-       struct blame_entry *ent;
-
-       for (ent = sb->ent; ent; ent = ent->next) {
-               /* Nobody should have zero or negative refcnt */
-               if (ent->suspect->refcnt <= 0) {
-                       fprintf(stderr, "%s in %s has negative refcnt %d\n",
-                               ent->suspect->path,
-                               oid_to_hex(&ent->suspect->commit->object.oid),
-                               ent->suspect->refcnt);
-                       baa = 1;
-               }
-       }
-       if (baa)
-               sb->on_sanity_fail(sb, baa);
-}
-
 static void sanity_check_on_fail(struct blame_scoreboard *sb, int baa)
 {
        int opt = OUTPUT_SHOW_SCORE | OUTPUT_SHOW_NUMBER | OUTPUT_SHOW_NAME;
-- 
2.9.3

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