sha1-name.c: for ":/", find detached HEAD commits

This patch broadens the set of commits matched by ":/<pattern>" to
include commits reachable from HEAD but not any named ref. This avoids
surprising behavior when working with a detached HEAD and trying to
refer to a commit that was recently created and only exists within the
detached state.

If multiple worktrees exist, only the current worktree's HEAD is
considered reachable. This is consistent with the existing behavior for
other per-worktree refs: e.g., bisect refs are considered reachable, but
only within the relevant worktree.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: William Chargin <wchargin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/revisions.txt b/Documentation/revisions.txt
index dfcc49c72c0fe8f90c5e66d8de30d7ad27582c2b..0845c3f590c646502114482526c171182e63da90 100644 (file)
--- a/Documentation/revisions.txt
+++ b/Documentation/revisions.txt
@@ -180,7 +180,8 @@ existing tag object.
   A colon, followed by a slash, followed by a text, names
   a commit whose commit message matches the specified regular expression.
   This name returns the youngest matching commit which is
-  reachable from any ref. The regular expression can match any part of the
+  reachable from any ref, including HEAD.
+  The regular expression can match any part of the
   commit message. To match messages starting with a string, one can use
   e.g. ':/^foo'. The special sequence ':/!' is reserved for modifiers to what
   is matched. ':/!-foo' performs a negative match, while ':/!!foo' matches a

diff --git a/sha1_name.c b/sha1_name.c
index 611c7d24ddee678470ba74cb3c2ca669a778b44a..19f66713e140094c934d96a94316f566350b4303 100644 (file)
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1649,6 +1649,7 @@ static int get_oid_with_context_1(const char *name,
                        struct commit_list *list = NULL;
 
                        for_each_ref(handle_one_ref, &list);
+                       head_ref(handle_one_ref, &list);
                        commit_list_sort_by_date(&list);
                        return get_oid_oneline(name + 2, oid, list);
                }

diff --git a/t/t4208-log-magic-pathspec.sh b/t/t4208-log-magic-pathspec.sh
index a1705f70cffe2332fc65f670797539986f330f70..69643d101d2130fe4f236719870e8929eca709f2 100755 (executable)
--- a/t/t4208-log-magic-pathspec.sh
+++ b/t/t4208-log-magic-pathspec.sh
@@ -25,6 +25,32 @@ test_expect_success '"git log :/a -- " should not be ambiguous' '
        git log :/a --
 '
 
+test_expect_success '"git log :/detached -- " should find a commit only in HEAD' '
+       test_when_finished "git checkout master" &&
+       git checkout --detach &&
+       # Must manually call `test_tick` instead of using `test_commit`,
+       # because the latter additionally creates a tag, which would make
+       # the commit reachable not only via HEAD.
+       test_tick &&
+       git commit --allow-empty -m detached &&
+       test_tick &&
+       git commit --allow-empty -m something-else &&
+       git log :/detached --
+'
+
+test_expect_success '"git log :/detached -- " should not find an orphaned commit' '
+       test_must_fail git log :/detached --
+'
+
+test_expect_success '"git log :/detached -- " should find HEAD only of own worktree' '
+       git worktree add other-tree HEAD &&
+       git -C other-tree checkout --detach &&
+       test_tick &&
+       git -C other-tree commit --allow-empty -m other-detached &&
+       git -C other-tree log :/other-detached -- &&
+       test_must_fail git log :/other-detached --
+'
+
 test_expect_success '"git log -- :/a" should not be ambiguous' '
        git log -- :/a
 '