[PATCH 6/8] t/t5333-pseudo-merge-bitmaps.sh: demonstrate empty pseudo-merge groups

From: Taylor Blau <me@ttaylorr.com>
Date: Aug 15, 2024, 17:31 UTC
Message-ID: <228553e412fc3020a6f24eea601c47a08d70a2bf.1723743050.git.me@ttaylorr.com>
In-Reply-To: <cover.1723743050.git.me@ttaylorr.com>

Demonstrate that it is possible to generate empty pseudo-merge commits in certain cases.

In the below instance, we generate one non-empty pseudo-merge (containing commit "base"), and one empty pseudo-merge group (corresponding to the unstable commits within that group).

(In my testing, the pseudo-merge machinery seems to handle empty groups just fine, but generating them is pointless as they carry no information.)

This commit (introducing a deliberate "test_expect_failure") is split out from the actual fix (which will appear in the following commit) to demonstrate that the failure is correctly induced.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 t/t5333-pseudo-merge-bitmaps.sh | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/t/t5333-pseudo-merge-bitmaps.sh b/t/t5333-pseudo-merge-bitmaps.sh
index f052f395a7..0288691340 100755
--- a/t/t5333-pseudo-merge-bitmaps.sh
+++ b/t/t5333-pseudo-merge-bitmaps.sh
@@ -390,4 +390,24 @@ test_expect_success 'pseudo-merge reuse' '
 	)
 '
 
+test_expect_failure 'empty pseudo-merge group' '
+	git init pseudo-merge-empty-group &&
+	(
+		cd pseudo-merge-empty-group &&
+
+		# Ensure that a pseudo-merge group with no unstable
+		# commits does not generate an empty pseudo-merge
+		# bitmap.
+		git config bitmapPseudoMerge.empty.pattern refs/ &&
+
+		test_commit base &&
+		git repack -adb &&
+
+		test-tool bitmap dump-pseudo-merges >merges &&
+		test_line_count = 1 merges &&
+
+		test 0 -eq "$(grep -c commits=0 <merges)"
+	)
+'
+
 test_done

-- 
2.46.0.54.gc9a64b1d2a