From 1a3119ed06c8fbb1c00a6aa3615299252575abab Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Fri, 24 Mar 2023 10:08:00 -0700 Subject: [PATCH] blame: allow --contents to work with non-HEAD commit The --contents option can be used with git blame to blame the file as if it had the contents from the specified file. This is akin to copying the contents into the working tree and then running git blame. This option has been supported since 1cfe77333f27 ("git-blame: no rev means start from the working tree file.") The --contents option always blames the file as if it was based on the current HEAD commit. If you try to pass a revision while using --contents, you get the following error: fatal: cannot use --contents with final commit object name 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. Note that the behavior of generating a fake working commit is still skipped when a revision is provided but --contents is not provided. Generating such a commit in that case would combine the currently checked out file contents with the provided revision, which breaks normal blame behavior and produces unexpected results. This enables use of --contents with an arbitrary revision, rather than forcing the use of the local HEAD commit. This makes the --contents option significantly more flexible, as it is no longer required to check out the working tree to the desired commit before using --contents. Reword the documentation so that its clear that --contents can be used with . Add tests for the --contents option to the annotate-tests.sh test script. Signed-off-by: Jacob Keller Signed-off-by: Junio C Hamano --- Documentation/blame-options.txt | 10 ++++----- Documentation/git-blame.txt | 2 +- blame.c | 40 +++++++++++++++++++++------------ t/annotate-tests.sh | 14 ++++++++++++ 4 files changed, 46 insertions(+), 20 deletions(-) diff --git a/Documentation/blame-options.txt b/Documentation/blame-options.txt index 9a663535f4..95599bd6e5 100644 --- a/Documentation/blame-options.txt +++ b/Documentation/blame-options.txt @@ -64,11 +64,11 @@ include::line-range-format.txt[] manual page. --contents :: - When is not specified, the command annotates the - changes starting backwards from the working tree copy. - This flag makes the command pretend as if the working - tree copy has the contents of the named file (specify - `-` to make the command read from the standard input). + Pretend the file being annotated has a commit with the + contents from the named file and a parent of , + defaulting to HEAD when no is specified. You may + specify '-' to make the command read from the standard + input for the file contents. --date :: Specifies the format used to output dates. If --date is not diff --git a/Documentation/git-blame.txt b/Documentation/git-blame.txt index 4400a17330..f69a871a96 100644 --- a/Documentation/git-blame.txt +++ b/Documentation/git-blame.txt @@ -12,7 +12,7 @@ SYNOPSIS [-L ] [-S ] [-M] [-C] [-C] [-C] [--since=] [--ignore-rev ] [--ignore-revs-file ] [--color-lines] [--color-by-age] [--progress] [--abbrev=] - [ | --contents | --reverse ..] [--] + [ --contents ] [ | --reverse ..] [--] DESCRIPTION ----------- diff --git a/blame.c b/blame.c index 8bfeaa1c63..2c1f47b944 100644 --- a/blame.c +++ b/blame.c @@ -176,12 +176,12 @@ static void set_commit_buffer_from_strbuf(struct repository *r, static struct commit *fake_working_tree_commit(struct repository *r, struct diff_options *opt, const char *path, - const char *contents_from) + const char *contents_from, + struct object_id *oid) { struct commit *commit; struct blame_origin *origin; struct commit_list **parent_tail, *parent; - struct object_id head_oid; struct strbuf buf = STRBUF_INIT; const char *ident; time_t now; @@ -197,10 +197,7 @@ 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); append_merge_parents(r, parent_tail); verify_working_tree_path(r, commit, path); @@ -2771,22 +2768,37 @@ 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")); - if (sb->reverse && sb->revs->first_parent_only) sb->revs->children.name = NULL; - if (!sb->final) { + 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". + * Build a fake commit at the top of the history, when + * (1) "git blame [^A] --path", i.e. with no 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 (defaulting 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), ":"); } diff --git a/t/annotate-tests.sh b/t/annotate-tests.sh index f1b9a6ce4d..b35be20cf3 100644 --- a/t/annotate-tests.sh +++ b/t/annotate-tests.sh @@ -72,6 +72,16 @@ test_expect_success 'blame 1 author' ' check_count A 2 ' +test_expect_success 'blame with --contents' ' + check_count --contents=file A 2 +' + +test_expect_success 'blame with --contents changed' ' + echo "1A quick brown fox jumps over the" >contents && + echo "another lazy dog" >>contents && + check_count --contents=contents A 1 "Not Committed Yet" 1 +' + test_expect_success 'blame in a bare repo without starting commit' ' git clone --bare . bare.git && ( @@ -98,6 +108,10 @@ test_expect_success 'blame 2 authors' ' check_count A 2 B 2 ' +test_expect_success 'blame with --contents and revision' ' + check_count -h testTag --contents=file A 2 "Not Committed Yet" 2 +' + test_expect_success 'setup B1 lines (branch1)' ' git checkout -b branch1 main && echo "3A slow green fox jumps into the" >>file &&