sha1_file: fix iterating loose alternate objects

The string in 'base' contains a path suffix to a specific object;
when its value is used, the suffix must either be filled (as in
stat_sha1_file, open_sha1_file, check_and_freshen_nonlocal) or
cleared (as in prepare_packed_git) to avoid junk at the end.

660c889e (sha1_file: add for_each iterators for loose and packed
objects, 2014-10-15) introduced loose_from_alt_odb(), but this did
neither and treated 'base' as a complete path to the "base" object
directory, instead of a pointer to the "base" of the full path
string.

The trailing path after 'base' is still initialized to NUL, hiding
the bug in some common cases.  Additionally the descendent
for_each_file_in_obj_subdir() function swallows ENOENT, so an error
only shows if the alternate's path was last filled with a valid
object (where statting /path/to/existing/00/0bjectfile/00 fails).

Signed-off-by: Jonathon Mah <me@JonathonMah.com>
Helped-by: Kyle J. McKay <mackyle@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/sha1_file.c b/sha1_file.c
index 725de7f..a41cc4f 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -3406,9 +3406,16 @@ static int loose_from_alt_odb(struct alternate_object_database *alt,
                              void *vdata)
 {
        struct loose_alt_odb_data *data = vdata;
-       return for_each_loose_file_in_objdir(alt->base,
-                                            data->cb, NULL, NULL,
-                                            data->data);
+       struct strbuf buf = STRBUF_INIT;
+       int r;
+
+       /* copy base not including trailing '/' */
+       strbuf_add(&buf, alt->base, alt->name - alt->base - 1);
+       r = for_each_loose_file_in_objdir_buf(&buf,
+                                             data->cb, NULL, NULL,
+                                             data->data);
+       strbuf_release(&buf);
+       return r;
 }
 
 int for_each_loose_object(each_loose_object_fn cb, void *data)

diff --git a/t/t5304-prune.sh b/t/t5304-prune.sh
index e32e46d..0794d33 100755 (executable)
--- a/t/t5304-prune.sh
+++ b/t/t5304-prune.sh
@@ -253,4 +253,12 @@ test_expect_success 'prune .git/shallow' '
        test_path_is_missing .git/shallow
 '
 
+test_expect_success 'prune: handle alternate object database' '
+       test_create_repo A &&
+       git -C A commit --allow-empty -m "initial commit" &&
+       git clone --shared A B &&
+       git -C B commit --allow-empty -m "next commit" &&
+       git -C B prune
+'
+
 test_done