Re: [PATCH v2] blame: allow --contents to work with non-HEAD commit
From: Junio C Hamano <hidden>
Date: 2023-03-24 15:30:36
Jacob Keller [off-list ref] writes:
This is because the blame process generates a fake working tree commit which always uses the HEAD object as its sole parent. Enhance fake_working_tree_commit to take the object ID to use for the parent instead of always using the HEAD object. Then, always generate a fake commit when we have contents provided, even if we have a final object. Remove the check to disallow --contents and a final revision.
Around here, probably in between the two paragraphs, it makes sense to explain why we do this enhancement only for --contents but not for the case where we take contents from the working tree file (that would ensure what I wrote will not go waste in my review ;-).
quoted hunk
diff --git a/Documentation/blame-options.txt b/Documentation/blame-options.txt index 9a663535f443..6476dd327377 100644 --- a/Documentation/blame-options.txt +++ b/Documentation/blame-options.txt@@ -64,11 +64,10 @@ include::line-range-format.txt[] manual page. --contents <file>:: + Pretend the file being annotated has the contents from the named + file instead of using the contents of <rev> or the working tree + copy. You may specify '-' to make the command read from standard + input for the file contents.
Hmph, I can sort of see that "or the working tree copy" refers to the behaviour when <rev> is not given, but I wonder if it makes it easier to understand to explicitly say that missing <rev> (or having no positive end) defaults to "HEAD" when choosing the parent of the fake commit with the given contents in it.
quoted hunk
@@ -198,10 +198,7 @@ static struct commit *fake_working_tree_commit(struct repository *r, commit->date = now; parent_tail = &commit->parents; - if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL)) - die("no such ref: HEAD"); - - parent_tail = append_parent(r, parent_tail, &head_oid); + parent_tail = append_parent(r, parent_tail, oid);
Good. As fake_working_tree_commit() is no longer about creating a fake commit based on "HEAD", we do not interpret "HEAD" here, and instead the caller is now responsible for feeding the fake parent object name to us.
quoted hunk
@@ -2772,22 +2769,30 @@ void setup_scoreboard(struct blame_scoreboard *sb, sb->commits.compare = compare_commits_by_reverse_commit_date; } - if (sb->final && sb->contents_from) - die(_("cannot use --contents with final commit object name")); -
OK.
+ if (sb->contents_from || !sb->final) {
+ struct object_id head_oid, *parent_oid;
+
/*
* "--not A B -- path" without anything positive;
* do not default to HEAD, but use the working tree
* or "--contents".
*/
This comment is no longer valid, as this block handles more cases now:
/*
* Build a fake commit at the tip of the history, when
* (1) "git blame ^A ^B -- path", i.e. without any positive
* end of the history range, in which case we build such
* a fake commit on top of the HEAD to blame in-tree
* modifications.
* (2) "git blame --contents=file [A] -- path", with or without
* positive end of the history range but with --contents,
* in which case we pretend that there is a fake commit
* on top of the positive end (defaults to HEAD) that
* has the given contents in the path.
*/
+ if (sb->final) {
+ parent_oid = &sb->final->object.oid;
+ } else {
+ if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
+ die("no such ref: HEAD");
+ parent_oid = &head_oid;
+ }
+
setup_work_tree();
sb->final = fake_working_tree_commit(sb->repo,
&sb->revs->diffopt,
- sb->path, sb->contents_from);
+ sb->path, sb->contents_from,
+ parent_oid);
add_pending_object(sb->revs, &(sb->final->object), ":");
}Other than that, looking good. Thanks.