From 62786f9a509a06ac031c066837d7a2285469677b Mon Sep 17 00:00:00 2001
From: Bryce Kwon <bryce@brycekwon.com>
Date: Sat, 8 Aug 2026 12:49:54 -1000
Subject: Emit generated runs in batches, not a write each

---
 tests/t0106-diff.sh | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

(limited to 'tests')

diff --git a/tests/t0106-diff.sh b/tests/t0106-diff.sh
index 3e0d15c..4074276 100755
--- a/tests/t0106-diff.sh
+++ b/tests/t0106-diff.sh
@@ -51,4 +51,57 @@ test_expect_success 'ssdiff still numbers a hunk that carries a length' '
 	grep "#n1.>1</a>" tmp
 '
 
+# --- Intra-line highlighting across many changed pairs ----------------------
+# The character-level highlight reuses one table across every changed pair.
+# Lines shrink down the file so a short comparison always follows a longer one,
+# which is where a stale cell would show up as misplaced del and add spans.
+test_expect_success 'set up a repo with shrinking changed lines' '
+	mkrepo repos/lcs 1 &&
+	(
+		cd repos/lcs &&
+		awk "BEGIN{for(n=120;n>0;n-=3){s=\"\";
+			for(i=0;i<n;i++)s=s sprintf(\"%c\",97+(i*7+n)%26); print s}}" >lines.txt &&
+		git add lines.txt &&
+		git commit -m "add lines.txt" &&
+		awk "BEGIN{for(n=120;n>0;n-=3){s=\"\";
+			for(i=0;i<n;i++){c=97+(i*7+n)%26; if(i%7==0)c=97+(c-97+5)%26;
+			s=s sprintf(\"%c\",c)} print s}}" >lines.txt &&
+		git commit -am "change every line"
+	) &&
+	{
+		echo "virtual-root=/" &&
+		echo "cache-size=0" &&
+		echo "repo.url=lcs" &&
+		echo "repo.path=$PWD/repos/lcs/.git"
+	} >lcsrc
+'
+
+test_expect_success 'every changed pair gets both a del and an add span' '
+	CGIT_CONFIG="$PWD/lcsrc" QUERY_STRING="url=lcs/diff/&dt=1" cgit >tmp &&
+	dels=$(grep -o "<span class=.del.>" tmp | wc -l) &&
+	adds=$(grep -o "<span class=.add.>" tmp | wc -l) &&
+	test "$dels" -gt 0 &&
+	test "$dels" -eq "$adds"
+'
+
+test_expect_success 'stripping the highlight leaves every line intact' '
+	sed -e "s/<[^>]*>//g" tmp >plain.out &&
+	git -C repos/lcs show HEAD~1:lines.txt >old.txt &&
+	git -C repos/lcs show HEAD:lines.txt >new.txt &&
+	while read -r line
+	do
+		grep -qF "$line" plain.out || {
+			echo "missing old line: $line"
+			return 1
+		}
+	done <old.txt &&
+	while read -r line
+	do
+		grep -qF "$line" plain.out || {
+			echo "missing new line: $line"
+			return 1
+		}
+	done <new.txt
+'
+
 test_done
-- 
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