When I reimplemented the most performance-critical bits of the interactive rebase in the sequencer, to speed up `git rebase -i` particularly on Windows (even if the benefits are still quite notable on Linux or macOS), I punted on the --root part.
I had always hoped that some other contributor (or I myself) would come back later to address the --root part in the sequencer, too, with the idea that this would move the last remaining complicated code from git-rebase--interactive.sh into sequencer.c, to facilitate converting the rest of git-rebase--interactive.sh. When I say "the last remaining complicated code", of course I neglect the --preserve-merges code, but as I worked hard on the --rebase-merges patch series with the intention to eventually deprecate and maybe even remove the --preserve-merges mode, I always implicitly assume that the --preserve-merges code will be moved into its own shell script (git-rebase--preserve-merges.sh, maybe?) and never be converted. So here goes: the patches to move the handling of --root into the sequencer. After two preparatory patches, the real conversion takes place in the third patch. After that, we take care of the --root related concerns that arise in conjunction with the --rebase-merges mode. As the --rebase-merges/--root patches overlap quite a bit (not so much in the code itself as in philosophical considerations such as "what should happen if you try to merge a branch into a new root", or the fact that the label/reset/merge commands make it desirable to be able to create a new root commit in the middle of a todo list), I had to consider in which order to contribute them. In the end, I decided to go with --rebase-merges first, so the --root patches are based on the --rebase-merges patch series. I consider this patch series a critical prerequisite for Alban's Google Summer of Code project to convert rebase -i into a builtin. Changes since v1: - Expanded is_pick_or_similar() to use a clear and verbose switch() statement, replacing the magic "command <= TODO_SQUASH". - Completely revamped read_author_ident(), using sq_dequote(); Sadly, trying to reuse builtin/am.c's read_author_script() would result in substantialy more lines of code, and I also failed to find an easy way to allow for arbitrary order of the environment variables in author-script. Johannes Schindelin (6): sequencer: extract helper to update active_cache_tree sequencer: learn about the special "fake root commit" handling rebase -i --root: let the sequencer handle even the initial part sequencer: allow introducing new root commits rebase --rebase-merges: a "merge" into a new root is a fast-forward rebase --rebase-merges: root commits can be cousins, too git-rebase--interactive.sh | 4 +- sequencer.c | 206 ++++++++++++++++++++++++++---- sequencer.h | 4 + t/t3404-rebase-interactive.sh | 19 ++- t/t3421-rebase-topology-linear.sh | 6 +- t/t3430-rebase-merges.sh | 72 +++++++++++ 6 files changed, 276 insertions(+), 35 deletions(-) base-commit: 673fb9cb8b5c7d57cb560b6ade45e419c8dd09fc Based-On: recreate-merges at https://github.com/dscho/git Fetch-Base-Via: git fetch https://github.com/dscho/git recreate-merges Published-As: https://github.com/dscho/git/releases/tag/sequencer-and-root-commits-v2 Fetch-It-Via: git fetch https://github.com/dscho/git sequencer-and-root-commits-v2 Branch-diff vs v1: 1: 42db734a980 ! 1: 73398da7119 sequencer: learn about the special "fake root commit" handling @@ -54,40 +54,50 @@ return NULL; } ++/* Read author-script and return an ident line (author <email> timestamp) */ +static const char *read_author_ident(struct strbuf *buf) +{ -+ char *p, *p2; ++ const char *keys[] = { ++ "GIT_AUTHOR_NAME=", "GIT_AUTHOR_EMAIL=", "GIT_AUTHOR_DATE=" ++ }; ++ char *in, *out, *eol; ++ int i = 0, len; + + if (strbuf_read_file(buf, rebase_path_author_script(), 256) <= 0) + return NULL; + -+ for (p = buf->buf; *p; p++) -+ if (skip_prefix(p, "'\\\\''", (const char **)&p2)) -+ strbuf_splice(buf, p - buf->buf, p2 - p, "'", 1); -+ else if (*p == '\'') -+ strbuf_splice(buf, p-- - buf->buf, 1, "", 0); -+ -+ if (skip_prefix(buf->buf, "GIT_AUTHOR_NAME=", (const char **)&p)) { -+ strbuf_splice(buf, 0, p - buf->buf, "", 0); -+ p = strchr(buf->buf, '\n'); -+ if (skip_prefix(p, "\nGIT_AUTHOR_EMAIL=", (const char **)&p2)) { -+ strbuf_splice(buf, p - buf->buf, p2 - p, " <", 2); -+ p = strchr(p, '\n'); -+ if (skip_prefix(p, "\nGIT_AUTHOR_DATE=@", -+ (const char **)&p2)) { -+ strbuf_splice(buf, p - buf->buf, p2 - p, -+ "> ", 2); -+ p = strchr(p, '\n'); -+ if (p) { -+ strbuf_setlen(buf, p - buf->buf); -+ return buf->buf; -+ } -+ } ++ /* dequote values and construct ident line in-place */ ++ for (in = out = buf->buf; i < 3 && in - buf->buf < buf->len; i++) { ++ if (!skip_prefix(in, keys[i], (const char **)&in)) { ++ warning("could not parse '%s' (looking for '%s'", ++ rebase_path_author_script(), keys[i]); ++ return NULL; + } -+ } -+ -+ warning(_("could not parse '%s'"), rebase_path_author_script()); -+ return NULL; ++ ++ eol = strchrnul(in, '\n'); ++ *eol = '\0'; ++ sq_dequote(in); ++ len = strlen(in); ++ ++ if (i > 0) /* separate values by spaces */ ++ *(out++) = ' '; ++ if (i == 1) /* email needs to be surrounded by <...> */ ++ *(out++) = '<'; ++ memmove(out, in, len); ++ out += len; ++ if (i == 1) /* email needs to be surrounded by <...> */ ++ *(out++) = '>'; ++ in = eol + 1; ++ } ++ ++ if (i < 3) { ++ warning("could not parse '%s' (looking for '%s')", ++ rebase_path_author_script(), keys[i]); ++ return NULL; ++ } ++ ++ buf->len = out - buf->buf; ++ return buf->buf; +} + static const char staged_changes_advice[] = @@ -159,7 +169,17 @@ +/* Does this command create a (non-merge) commit? */ +static int is_pick_or_similar(enum todo_command command) +{ -+ return command <= TODO_SQUASH; ++ switch (command) { ++ case TODO_PICK: ++ case TODO_REVERT: ++ case TODO_EDIT: ++ case TODO_REWORD: ++ case TODO_FIXUP: ++ case TODO_SQUASH: ++ return 1; ++ default: ++ return 0; ++ } +} + static int update_squash_messages(enum todo_command command, 2: 1c8740eaa91 = 2: 2dfe8315993 rebase -i --root: let the sequencer handle even the initial part 3: 8a7f5751412 = 3: 0ee765bbb36 sequencer: allow introducing new root commits 4: 0b7379b576b = 4: 29d7a9265e3 rebase --rebase-merges: a "merge" into a new root is a fast-forward 5: 270b8fdf477 = 5: f7ee1b3de12 rebase --rebase-merges: root commits can be cousins, too -- 2.17.0.windows.1.38.g05ca542f78d
