From 8d38a56221dff0df80fad41dc61bbc4131d96169 Mon Sep 17 00:00:00 2001
From: Bryce Kwon <bryce@brycekwon.com>
Date: Wed, 4 Nov 2026 23:13:43 -1000
Subject: Put a Lua filter's print output where it runs

LuaJIT and Lua 5.1 leave print's line in stdio's buffer until cgit
exits, after the end of the page.
---
 tests/t0201-filters.sh | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

(limited to 'tests')

diff --git a/tests/t0201-filters.sh b/tests/t0201-filters.sh
index 8d8743a..4b39f18 100755
--- a/tests/t0201-filters.sh
+++ b/tests/t0201-filters.sh
@@ -168,4 +168,24 @@ test_expect_success CGIT_LUA 'a lua filter can encode an argument and include a
 	grep "a+b%26c|included <b>bold</b>" tmp
 '
 
+# The print of LuaJIT and Lua 5.1 leaves its line in stdio's buffer, which only
+# reached the page as cgit exited, behind the closing tag. A print lands where
+# the filter runs.
+test_expect_success CGIT_LUA 'a lua filter prints where it runs' '
+	cat >print.lua <<-\EOF &&
+	function filter_open(...) end
+	function filter_write(str)
+		print("printed", 1, nil, true)
+		html(str)
+	end
+	function filter_close() return 0 end
+	EOF
+	sed "s|loud.lua|print.lua|" loudrc >printrc &&
+	cgit_rc printrc "url=foo/commit" >tmp &&
+	tab=$(printf "\t") &&
+	grep "<div class=.commit-subject.>printed${tab}1${tab}nil${tab}true$" tmp &&
+	sed -n "/<\/html>/,\$p" tmp >tail &&
+	! grep printed tail
+'
+
 test_done
-- 
cgit 2.12.1