blame: fix object casting regression

Commit 1b0d400 refactored the prepare_final() function so
that it could be reused in multiple places. Originally, the
loop had two outputs: a commit to stuff into sb->final, and
the name of the commit from the rev->pending array.

After the refactor, that loop is put in its own function
with a single return value: the object_array_entry from the
rev->pending array. This contains both the name and the object,
but with one important difference: the object is the
_original_ object found by the revision parser, not the
dereferenced commit. If one feeds a tag to "git blame", we
end up casting the tag object to a "struct commit", which
causes a segfault.

Instead, let's return the commit (properly casted) directly
from the function, and take the "name" as an optional
out-parameter. This does the right thing, and actually
simplifies the callers, who no longer need to cast or
dereference the object_array_entry themselves.

[test case by Max Kirillov <max@max630.net>]

Signed-off-by: Jeff King <peff@peff.net>
This commit is contained in:
Jeff King 2015-11-17 18:22:37 -05:00
parent 700fd28e4f
commit 7cb5f7c44d
2 changed files with 21 additions and 16 deletions

View File

@ -2396,10 +2396,12 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
return commit;
}
static struct object_array_entry *find_single_final(struct rev_info *revs)
static struct commit *find_single_final(struct rev_info *revs,
const char **name_p)
{
int i;
struct object_array_entry *found = NULL;
struct commit *found = NULL;
const char *name = NULL;
for (i = 0; i < revs->pending.nr; i++) {
struct object *obj = revs->pending.objects[i].item;
@ -2411,22 +2413,20 @@ static struct object_array_entry *find_single_final(struct rev_info *revs)
die("Non commit %s?", revs->pending.objects[i].name);
if (found)
die("More than one commit to dig from %s and %s?",
revs->pending.objects[i].name,
found->name);
found = &(revs->pending.objects[i]);
revs->pending.objects[i].name, name);
found = (struct commit *)obj;
name = revs->pending.objects[i].name;
}
if (name_p)
*name_p = name;
return found;
}
static char *prepare_final(struct scoreboard *sb)
{
struct object_array_entry *found = find_single_final(sb->revs);
if (found) {
sb->final = (struct commit *) found->item;
return xstrdup(found->name);
} else {
return NULL;
}
const char *name;
sb->final = find_single_final(sb->revs, &name);
return xstrdup_or_null(name);
}
static char *prepare_initial(struct scoreboard *sb)
@ -2712,11 +2712,9 @@ parse_done:
die("Cannot use --contents with final commit object name");
if (reverse && revs.first_parent_only) {
struct object_array_entry *entry = find_single_final(sb.revs);
if (!entry)
final_commit = find_single_final(sb.revs, NULL);
if (!final_commit)
die("--reverse and --first-parent together require specified latest commit");
else
final_commit = (struct commit*) entry->item;
}
/*

View File

@ -68,6 +68,13 @@ test_expect_success 'blame 1 author' '
check_count A 2
'
test_expect_success 'blame by tag objects' '
git tag -m "test tag" testTag &&
git tag -m "test tag #2" testTag2 testTag &&
check_count -h testTag A 2 &&
check_count -h testTag2 A 2
'
test_expect_success 'setup B lines' '
echo "2A quick brown fox jumps over the" >>file &&
echo "lazy dog" >>file &&