[PATCH 11/18] alternates: encapsulate alt->base munging

[Jeff King]

The alternate_object_database struct holds a path to the
alternate objects, but we also use that buffer as scratch
space for forming loose object filenames. Let's pull that
logic into a helper function so that we can more easily
modify it.

Signed-off-by: Jeff King <p...@peff.net>
---
 sha1_file.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/sha1_file.c b/sha1_file.c
index 549cf1e..ccf59ba 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -204,6 +204,13 @@ const char *sha1_file_name(const unsigned char *sha1)
        return buf;
 }
 
+static const char *alt_sha1_path(struct alternate_object_database *alt,
+                                const unsigned char *sha1)
+{
+       fill_sha1_path(alt->name, sha1);
+       return alt->base;
+}
+
 /*
  * Return the name of the pack or index file with the specified sha1
  * in its filename.  *base and *name are scratch space that must be
@@ -601,8 +608,8 @@ static int check_and_freshen_nonlocal(const unsigned char 
*sha1, int freshen)
        struct alternate_object_database *alt;
        prepare_alt_odb();
        for (alt = alt_odb_list; alt; alt = alt->next) {
-               fill_sha1_path(alt->name, sha1);
-               if (check_and_freshen_file(alt->base, freshen))
+               const char *path = alt_sha1_path(alt, sha1);
+               if (check_and_freshen_file(path, freshen))
                        return 1;
        }
        return 0;
@@ -1600,8 +1607,8 @@ static int stat_sha1_file(const unsigned char *sha1, 
struct stat *st)
        prepare_alt_odb();
        errno = ENOENT;
        for (alt = alt_odb_list; alt; alt = alt->next) {
-               fill_sha1_path(alt->name, sha1);
-               if (!lstat(alt->base, st))
+               const char *path = alt_sha1_path(alt, sha1);
+               if (!lstat(path, st))
                        return 0;
        }
 
@@ -1621,8 +1628,8 @@ static int open_sha1_file(const unsigned char *sha1)
 
        prepare_alt_odb();
        for (alt = alt_odb_list; alt; alt = alt->next) {
-               fill_sha1_path(alt->name, sha1);
-               fd = git_open_noatime(alt->base);
+               const char *path = alt_sha1_path(alt, sha1);
+               fd = git_open_noatime(path);
                if (fd >= 0)
                        return fd;
                if (most_interesting_errno == ENOENT)
-- 
2.10.0.618.g82cc264