fix: exit() and dd() support in worker mode (#1946)

* Verifies exit behavior.

* formatting

* Checks for actual exit.

* Fixes test.

* Fixes test.

* Update testdata/dd.php

Co-authored-by: Kévin Dunglas <kevin@dunglas.fr>

---------

Co-authored-by: Kévin Dunglas <kevin@dunglas.fr>

Author: AlliBalliBaba

caddy/caddy_test.go

@@ -1423,3 +1423,27 @@ func TestWorkerMatchDirectiveWithoutFileServer(t *testing.T) {
 	// the request should completely fall through the php_server module
 	tester.AssertGetResponse("http://localhost:"+testPort+"/static.txt", http.StatusNotFound, "Request falls through")
 }
+
+func TestDd(t *testing.T) {
+	tester := caddytest.NewTester(t)
+	tester.InitServer(`
+		{
+			skip_install_trust
+			admin localhost:2999
+		}
+
+		http://localhost:`+testPort+` {
+			php {
+				worker ../testdata/dd.php 1 {
+					match *
+				}
+			}
+		`, "caddyfile")
+
+	// simulate Symfony's dd()
+	tester.AssertGetResponse(
+		"http://localhost:"+testPort+"/some-path?output=dump123",
+		http.StatusInternalServerError,
+		"dump123",
+	)
+}

frankenphp.c

@@ -464,12 +464,16 @@ PHP_FUNCTION(frankenphp_handle_request) {
 
   /*
    * If an exception occurred, print the message to the client before
-   * closing the connection and bailout.
+   * closing the connection.
    */
-  if (EG(exception) && !zend_is_unwind_exit(EG(exception)) &&
-      !zend_is_graceful_exit(EG(exception))) {
-    zend_exception_error(EG(exception), E_ERROR);
-    zend_bailout();
+  if (EG(exception)) {
+    if (!zend_is_unwind_exit(EG(exception)) &&
+        !zend_is_graceful_exit(EG(exception))) {
+      zend_exception_error(EG(exception), E_ERROR);
+    } else {
+      /* exit() will jump directly to after php_execute_script */
+      zend_bailout();
+    }
   }
 
   frankenphp_worker_request_shutdown();

testdata/dd.php

@@ -0,0 +1,32 @@
+<?php
+
+// simulate Symfony's dd() behavior
+// see https://github.com/symfony/http-kernel/blob/7.3/DataCollector/DumpDataCollector.php#L216
+class Dumper
+{
+    private string $message;
+
+    public function dump(string $message): void
+    {
+        http_response_code(500);
+        $this->message = $message;
+    }
+
+    public function __destruct()
+    {
+        if (isset($this->message)) {
+            echo $this->message;
+        }
+    }
+}
+
+$dumper = new Dumper();
+
+while (frankenphp_handle_request(function () use ($dumper) {
+    $dumper->dump($_GET['output'] ?? '');
+    exit(1);
+})) {
+    // keep handling requests
+}
+
+echo "we should never reach here\n";