[PATCH v2 2/3] diff: fix filtering of additional headers under --remerge-diff

["Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com>]

From: Elijah Newren <newren@gmail.com>

Commit 95433eeed9 ("diff: add ability to insert additional headers for
paths", 2022-02-02) introduced the possibility of additional headers.
Because there could be conflicts with no content differences (e.g. a
modify/delete conflict resolved in favor of taking the modified file
as-is), that commit also modified the diff_queue_is_empty() and
diff_flush_patch() logic to ensure these headers were included even if
there was no associated content diff.

However, when the pickaxe is active, we really only want the remerge
conflict headers to be shown when there is an associated content diff.
Adjust the logic in these two functions accordingly.

This also removes the TEST_PASSES_SANITIZE_LEAK=true declaration from
t4069, as there is apparently some kind of memory leak with the pickaxe
code.

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 diff.c                  |  2 ++
 t/t4069-remerge-diff.sh | 17 ++++++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/diff.c b/diff.c
index d672efed7ab..85905261ce4 100644
--- a/diff.c
+++ b/diff.c
@@ -5860,6 +5860,7 @@ static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
 {
 	int include_conflict_headers =
 	    (additional_headers(o, p->one->path) &&
+	     !o->pickaxe_opts &&
 	     (!o->filter || filter_bit_tst(DIFF_STATUS_UNMERGED, o)));
 
 	/*
@@ -5915,6 +5916,7 @@ int diff_queue_is_empty(struct diff_options *o)
 	int i;
 	int include_conflict_headers =
 	    (o->additional_path_headers &&
+	     !o->pickaxe_opts &&
 	     (!o->filter || filter_bit_tst(DIFF_STATUS_UNMERGED, o)));
 
 	if (include_conflict_headers)
diff --git a/t/t4069-remerge-diff.sh b/t/t4069-remerge-diff.sh
index e3e6fbd97b2..95a16d19aec 100755
--- a/t/t4069-remerge-diff.sh
+++ b/t/t4069-remerge-diff.sh
@@ -2,7 +2,6 @@
 
 test_description='remerge-diff handling'
 
-TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # This test is ort-specific
@@ -90,6 +89,22 @@ test_expect_success 'remerge-diff with both a resolved conflict and an unrelated
 	test_cmp expect actual
 '
 
+test_expect_success 'pickaxe still includes additional headers for relevant changes' '
+	# reuses "expect" from the previous testcase
+
+	git log --oneline --remerge-diff -Sacht ab_resolution >tmp &&
+	sed -e "s/[0-9a-f]\{7,\}/HASH/g" tmp >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'can filter out additional headers with pickaxe' '
+	git show --remerge-diff --submodule=log --find-object=HEAD ab_resolution >actual &&
+	test_must_be_empty actual &&
+
+	git show --remerge-diff -S"not present" --all >actual &&
+	test_must_be_empty actual
+'
+
 test_expect_success 'setup non-content conflicts' '
 	git switch --orphan base &&
 
-- 
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