Fix memory leak in capture tests by using test_http_write callback

The capture tests (large_body_capture, grwprintf_truncation_bug) were calling
hs_request_begin_write which would call hs_request_terminate_connection
on write error, freeing the request. But the tests then tried to use the
captured buffer which was now owned by the request.

Fix: Have test_http_write callback also capture bytes when in CAPTURE mode
by calling hs_test_write directly. This allows proper cleanup via
destroy_test_request without double-free.

Also adds hs_test_write declaration to test_write_socket.h for proper
extern access.

Author: jeremycw

test/unit/test_respond.c

@@ -12,6 +12,10 @@ static int http_write_call_count = 0;
 
 static void test_http_write(struct http_request_s* request) {
   http_write_call_count++;
+  if (hs_test_write_mode == HS_TEST_WRITE_CAPTURE) {
+    hs_test_enable_write_stub(1);
+    hs_test_write(request->socket, request->buffer.buf, request->buffer.length);
+  }
 }
 
 static struct http_request_s* setup_test_request(void) {
@@ -111,7 +115,7 @@ MunitResult test_respond_large_body_capture(const MunitParameter params[], void*
   memset(large_body, 'X', 2048);
   hs_response_set_body(response, large_body, 2048);
 
-  hs_request_respond(request, response, hs_request_begin_write);
+  hs_request_respond(request, response, test_http_write);
 
   char* headers_end = strstr(captured_write_buf, "\r\n\r\n");
   munit_assert_ptr_not_null(headers_end);
@@ -124,6 +128,7 @@ MunitResult test_respond_large_body_capture(const MunitParameter params[], void*
 
   hs_test_enable_write_stub(0);
   hs_test_reset_capture();
+  destroy_test_request(request);
 
   return MUNIT_OK;
 }
@@ -156,7 +161,7 @@ MunitResult test_respond_grwprintf_truncation_bug(const MunitParameter params[],
   memset(body, 'Y', 64);
   hs_response_set_body(response, body, 64);
 
-  hs_request_respond(request, response, hs_request_begin_write);
+  hs_request_respond(request, response, test_http_write);
 
   munit_assert_ptr_not_null(captured_write_buf);
   munit_assert_size(captured_write_size, >, 0);
@@ -179,6 +184,7 @@ MunitResult test_respond_grwprintf_truncation_bug(const MunitParameter params[],
 
   hs_test_enable_write_stub(0);
   hs_test_reset_capture();
+  destroy_test_request(request);
 
   return MUNIT_OK;
 }

test/unit/test_write_socket.h

@@ -11,6 +11,7 @@ extern enum hs_test_write_mode_e hs_test_write_mode;
 
 void hs_test_enable_write_stub(int enabled);
 void hs_test_reset_capture(void);
+ssize_t hs_test_write(int fd, char const *data, size_t size);
 extern char* captured_write_buf;
 extern size_t captured_write_size;