[PATCH] revision: fix --no-walk path filtering regression

["Kristofer Karlsson via GitGitGadget" <gitgitgadget@gmail.com>]

From: Kristofer Karlsson <krka@spotify.com>

Since dd4bc01c0a (revision: use priority queue for non-limited
streaming walks, 2026-05-27), "git rev-list --no-walk <commit>
-- <path>" ignores the path arguments and outputs all commits
regardless of whether they touch the given paths.

That commit introduced a REV_WALK_NO_WALK enum value to separate
--no-walk from the streaming walk in get_revision_1(). The new
case skips process_parents(), which is correct for not enqueuing
parents, but also skips try_to_simplify_commit() which
process_parents() calls to evaluate whether each commit touches
the given paths.

Add a call to try_to_simplify_commit() for the
REV_WALK_NO_WALK case, folding it into the existing
REV_WALK_REFLOG case which already does the same.

Add tests for --no-walk path filtering to t6017. The
"single commit, match" test is defensive and passes without
the fix, while the other two fail without it.

Reported-by: Peter Colberg <pcolberg@redhat.com>
Signed-off-by: Kristofer Karlsson <krka@spotify.com>
---
    revision: fix --no-walk path filtering regression
    
    Fix for a regression reported by Peter Colberg [1] where git rev-list
    --no-walk <commit> -- <path> ignores path arguments since dd4bc01c0a.
    
    Verified against linux.git with the exact example from the report:
    
    git rev-list --topo-order v7.0..v7.1 -- drivers/gpu/drm/ |
    git rev-list --stdin --no-walk=unsorted -- ':!drivers/gpu/drm/'
    
    
    Without fix: 2026 commits (all pass through unfiltered) With fix: 146
    commits (correctly filtered)
    
    [1]
    https://lore.kernel.org/git/CAL71e4NjDTHbKR8z7pSrPpzDrX19JOTR04sArm7P=m5ivqkskA@mail.gmail.com/T/#u

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2181%2Fspkrka%2Fkk%2Fno-walk-pathspec-fix-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2181/spkrka/kk/no-walk-pathspec-fix-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/2181

 revision.c                |  2 +-
 t/t6017-rev-list-stdin.sh | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/revision.c b/revision.c
index ccbe2e03d1..e990e3f96b 100644
--- a/revision.c
+++ b/revision.c
@@ -4419,6 +4419,7 @@ static struct commit *get_revision_1(struct rev_info *revs)
 
 		switch (mode) {
 		case REV_WALK_REFLOG:
+		case REV_WALK_NO_WALK:
 			try_to_simplify_commit(revs, commit);
 			break;
 		case REV_WALK_TOPO:
@@ -4432,7 +4433,6 @@ static struct commit *get_revision_1(struct rev_info *revs)
 					    oid_to_hex(&commit->object.oid));
 			}
 			break;
-		case REV_WALK_NO_WALK:
 		case REV_WALK_LIMITED:
 			break;
 		}
diff --git a/t/t6017-rev-list-stdin.sh b/t/t6017-rev-list-stdin.sh
index 4821b90e74..32284f1831 100755
--- a/t/t6017-rev-list-stdin.sh
+++ b/t/t6017-rev-list-stdin.sh
@@ -148,4 +148,22 @@ test_expect_success '--not via stdin does not influence revisions from command l
 	test_cmp expect actual
 '
 
+test_expect_success '--no-walk filters by path (single commit, match)' '
+	git rev-parse side-1 >expect &&
+	git rev-list --no-walk side-1 -- file-1 >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--no-walk filters by path (single commit, no match)' '
+	git rev-list --no-walk side-2 -- file-1 >actual &&
+	test_must_be_empty actual
+'
+
+test_expect_success '--no-walk with pathspec exclusion' '
+	git rev-parse side-3 side-2 >expect &&
+	git rev-parse side-1 side-2 side-3 >input &&
+	git rev-list --stdin --no-walk -- ":!file-1" <input >actual &&
+	test_cmp expect actual
+'
+
 test_done

base-commit: d35c5399e3e54ac277bb391fc2f6be3e816d312b
-- 
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