test: Fix a flaky test_proxy_07_cache_control.py (seen on Windows CI).

test/modules/proxy/env.py

@@ -57,6 +57,17 @@ def _process(self):
                     # capture request to backend
                     self._request = data
                     c.sendall(self._make_response(data))
+                    # Half-close for an orderly FIN instead of letting the
+                    # OS tear the socket down under us. An abrupt close()
+                    # right after sendall() can, depending on the platform's
+                    # TCP stack and buffering, surface to the peer as a
+                    # reset rather than a clean end of the response, which
+                    # httpd's proxy and cache code treat as an aborted
+                    # connection and a reason to discard the cache entry.
+                    try:
+                        c.shutdown(socket.SHUT_WR)
+                    except OSError:
+                        pass
                 finally:
                     c.close()
             except socket.timeout:

test/modules/proxy/test_07_cache_control.py

@@ -1,4 +1,5 @@
 import os
+import time
 import uuid
 
 import pytest
@@ -131,6 +132,12 @@ def test_proxy_07_001(self, env, index):
     def test_proxy_07_002(self, env, index):
         cc = ", ".join(CASES[index][0])
         r1 = self.get(env, index)
+        # The cache entry for r1 is committed by the CACHE_SAVE filter on
+        # the EOS-only pass that follows the body, which can still be
+        # running server side for an instant after the body itself has
+        # already reached this process. Give it room to land before relying
+        # on it, instead of risking a spurious backend hit on r2.
+        time.sleep(0.1)
         r2 = self.get(env, index)
         assert self.backend_hits(index) == 1, f"Cache-Control: {cc} not cached"
         assert r2["header"]["x-cache"].startswith("HIT")
@@ -145,6 +152,9 @@ def test_proxy_07_003(self, env, index):
         r1 = self.get(env, index)
         assert r1["header"]["x-secret"] == "s"
         assert r1["header"]["set-cookie"] == "a=b"
+        # See test_proxy_07_002: give the CACHE_SAVE filter's commit time
+        # to land before asserting on it.
+        time.sleep(0.1)
         r2 = self.get(env, index)
         assert self.backend_hits(index) == 1, f"Cache-Control: {cc} not cached"
         assert r2["header"]["x-cache"].startswith("HIT")