From 6a9b662b50927b2dbe3c8d383f04d1d7b649b28f Mon Sep 17 00:00:00 2001
From: Bryce Kwon <bryce@brycekwon.com>
Date: Sat, 8 Aug 2026 12:49:57 -1000
Subject: Gather page output into one buffer

---
 tests/t0020-validate-cache.sh | 49 +++++++++++++++++++++++++++++++++++++++++++
 tests/t0111-filter.sh         | 16 ++++++++++++++
 2 files changed, 65 insertions(+)

(limited to 'tests')

diff --git a/tests/t0020-validate-cache.sh b/tests/t0020-validate-cache.sh
index 657765d..7e6334c 100755
--- a/tests/t0020-validate-cache.sh
+++ b/tests/t0020-validate-cache.sh
@@ -75,4 +75,53 @@ test_expect_success 'verify cache-size=1021' '
 	test_cmp output.full output.second
 '
 
+# --- A cached page must hold everything the uncached one produced -----------
+# Page output is buffered, so the slot is only complete if the buffer is
+# emptied before the generated content is measured. The blob here is larger
+# than one buffer, so a missing flush would truncate the cached copy.
+test_expect_success 'set up a repo with a page larger than the output buffer' '
+	mkrepo repos/bigpage 1 &&
+	(
+		cd repos/bigpage &&
+		awk "BEGIN{for(i=0;i<20000;i++) print \"line \" i \" of the big file\"}" >big.txt &&
+		git add big.txt &&
+		git commit -m "add big.txt"
+	) &&
+	{
+		echo "virtual-root=/" &&
+		echo "cache-root=$PWD/cache2" &&
+		echo "cache-size=64" &&
+		echo "enable-tree-linenumbers=1" &&
+		echo "repo.url=bigpage" &&
+		echo "repo.path=$PWD/repos/bigpage/.git"
+	} >bigrc &&
+	rm -rf cache2 && mkdir cache2
+'
+
+bigq() { CGIT_CONFIG="$PWD/bigrc" QUERY_STRING="$1" cgit; }
+
+test_expect_success 'the first request fills the slot and the second replays it' '
+	bigq "url=bigpage/tree/big.txt" >big.first &&
+	test $(wc -c <big.first) -gt 65536 &&
+	bigq "url=bigpage/tree/big.txt" >big.second &&
+	strip_headers <big.first >big.first.body &&
+	strip_headers <big.second >big.second.body &&
+	test_cmp big.first.body big.second.body
+'
+
+test_expect_success 'the cached body matches one generated with the cache off' '
+	sed -e "s/^cache-size=64$/cache-size=0/" bigrc >bignocache &&
+	CGIT_CONFIG="$PWD/bignocache" QUERY_STRING="url=bigpage/tree/big.txt" cgit >big.nocache &&
+	strip_headers <big.nocache >big.nocache.body &&
+	# The footer carries the time the page was generated, which differs
+	# between the two runs by construction.
+	sed -e "s/generated by .*//" big.nocache.body >big.a &&
+	sed -e "s/generated by .*//" big.second.body >big.b &&
+	test_cmp big.a big.b
+'
+
+test_expect_success 'the page ends where it should, so nothing was dropped' '
+	tail -c 200 big.second.body | grep "</html>"
+'
+
 test_done
diff --git a/tests/t0111-filter.sh b/tests/t0111-filter.sh
index 2fdc366..da4172f 100755
--- a/tests/t0111-filter.sh
+++ b/tests/t0111-filter.sh
@@ -41,6 +41,22 @@ do
 	test_expect_success "check whether the $prefix email filter works for committers" '
 		grep "<committer@example.com> commit C O MITTER &LT;COMMITTER@EXAMPLE.COM&GT;" tmp
 	'
+
+	# Page output is buffered, so anything written before a filter opens has
+	# to leave the buffer before the filter takes over stdout, and anything
+	# written while it is open has to leave before stdout is handed back.
+	# A missed flush reorders the page rather than losing it, so check that
+	# the markup around the filtered text is still on the right side of it.
+	test_expect_success "the $prefix source filter output stays inside its cell" "
+		cgit_url 'filter-$prefix/tree/a%2bb' >tmp &&
+		tr -d '\n' <tmp >flat.out &&
+		grep '<code>a+b HELLO</code>' flat.out
+	"
+
+	test_expect_success "the $prefix about filter output stays inside its div" "
+		cgit_url 'filter-$prefix/about/' >tmp &&
+		grep \"<div id='summary'>a+b HELLO\" tmp
+	"
 done
 
 test_done
-- 
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