1 file changed, 29 insertions, 1 deletion
diff --git a/tests/t0003-cache.sh b/tests/t0003-cache.sh
index ec88046..d247ae4 100755
--- a/tests/t0003-cache.sh
+++ b/tests/t0003-cache.sh
@@ -231,7 +231,7 @@ test_expect_success 'a failed final write still delivers the page' '
 
 # The second request lands while the first is inside its filter, which says
 # so through a marker file, since a fresh binary can take a moment to start.
-overlap_requests() {
+start_first_request() {
 	n=0
 	rm -f filter-running
 	cgit_rc lockrc "url=bigpage/about/" >first.out 2>first.err &
@@ -240,6 +240,10 @@ overlap_requests() {
 		sleep 1
 		n=$((n + 1))
 	done
+}
+
+overlap_requests() {
+	start_first_request
 	cgit_rc lockrc "url=bigpage/log/" >/dev/null 2>second.err
 	wait
 }
@@ -269,6 +273,30 @@ test_expect_success 'a slot stays locked while an exec filter runs' '
 	! grep "Unable to lock" second.err
 '
 
+# A request that opens the lock file just before its holder renames it into
+# place as the live slot goes on to lock the slot itself. strace holds the
+# second request's flock back until the first has finished, and the check
+# that the path still names the locked file turns that lock down, so the
+# slot keeps the first request's key. strace needs ptrace and a version that
+# can delay a call, which some systems do not give.
+test_lazy_prereq STRACE_DELAY '
+	strace -o /dev/null -e inject=flock:delay_enter=1 true
+'
+
+test_expect_success STRACE_DELAY 'a lock taken after the rename leaves the slot alone' '
+	rm -rf cache3 && mkdir cache3 &&
+	start_first_request &&
+	strace -o /dev/null -e inject=flock:delay_enter=4000000 \
+		-E CGIT_CONFIG="$PWD/lockrc" -E QUERY_STRING="url=bigpage/log/" \
+		cgit >second.out 2>second.err &&
+	wait &&
+	grep "id=.about." first.out &&
+	grep "</html>" second.out &&
+	tr "\000" "\n" <"cache3/$(ls cache3)" | head -n 1 >slot.key &&
+	grep "about" slot.key &&
+	! grep "log" slot.key
+'
+
 # An flock lasts until the last copy of its descriptor closes, so a filter
 # may hold the slot's lock file only as the stdout it writes the page to. A
 # stray copy would keep the slot locked for as long as the filter, or