Fix exception thrown during fiber destruction

Previously an exception thrown during fiber destruction resulted in a fatal error, but that exception should be able to be caught (unless we’ve entered shutdown, then still use a fatal error so the error is not hidden).

Author: trowski

Zend/tests/fibers/suspend-in-force-close-fiber-after-shutdown.phpt

@@ -1,5 +1,5 @@
 --TEST--
-Suspend in force closed fiber after shutdown
+Suspend in force-closed fiber after shutdown
 --FILE--
 <?php
 
@@ -19,7 +19,7 @@ echo "done\n";
 --EXPECTF--
 done
 
-Fatal error: Uncaught FiberError: Cannot suspend in a force closed fiber in %ssuspend-in-force-close-fiber-after-shutdown.php:%d
+Fatal error: Uncaught FiberError: Cannot suspend in a force-closed fiber in %ssuspend-in-force-close-fiber-after-shutdown.php:%d
 Stack trace:
 #0 %ssuspend-in-force-close-fiber-after-shutdown.php(%d): Fiber::suspend()
 #1 [internal function]: {closure}()

Zend/tests/fibers/suspend-in-force-close-fiber-catching-exception.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Suspend in force-closed fiber, catching exception thrown from destructor
+--FILE--
+<?php
+
+try {
+    (function (): void {
+        $fiber = new Fiber(function (): void {
+            try {
+                Fiber::suspend();
+            } finally {
+                Fiber::suspend();
+            }
+        });
+
+        $fiber->start();
+    })();
+} catch (FiberError $exception) {
+    echo $exception->getMessage(), "\n";
+}
+
+echo "done\n";
+
+?>
+--EXPECTF--
+Cannot suspend in a force-closed fiber
+done

Zend/tests/fibers/suspend-in-force-close-fiber.phpt

@@ -1,5 +1,5 @@
 --TEST--
-Suspend in force closed fiber
+Suspend in force-closed fiber
 --FILE--
 <?php
 
@@ -17,7 +17,7 @@ unset($fiber);
 
 ?>
 --EXPECTF--
-Fatal error: Uncaught FiberError: Cannot suspend in a force closed fiber in %ssuspend-in-force-close-fiber.php:%d
+Fatal error: Uncaught FiberError: Cannot suspend in a force-closed fiber in %ssuspend-in-force-close-fiber.php:%d
 Stack trace:
 #0 %ssuspend-in-force-close-fiber.php(%d): Fiber::suspend()
 #1 [internal function]: {closure}()

Zend/tests/fibers/unfinished-fiber-with-throw-in-finally.phpt

@@ -44,5 +44,5 @@ fiber
 inner finally
 finally exception
 outer finally
-Cannot suspend in a force closed fiber
+Cannot suspend in a force-closed fiber
 done

Zend/zend_fibers.c

@@ -349,8 +349,6 @@ static void ZEND_STACK_ALIGNED zend_fiber_execute(zend_fiber_context *context)
 		if (fiber->status == ZEND_FIBER_STATUS_SHUTDOWN) {
 			if (EXPECTED(zend_is_graceful_exit(EG(exception)) || zend_is_unwind_exit(EG(exception)))) {
 				zend_clear_exception();
-			} else {
-				zend_exception_error(EG(exception), E_ERROR);
 			}
 		} else {
 			fiber->status = ZEND_FIBER_STATUS_THREW;
@@ -380,14 +378,24 @@ static void zend_fiber_object_destroy(zend_object *object)
 {
 	zend_fiber *fiber = (zend_fiber *) object;
 
-	if (fiber->status == ZEND_FIBER_STATUS_SUSPENDED) {
-		zend_object *exception = EG(exception);
-		EG(exception) = NULL;
+	if (fiber->status != ZEND_FIBER_STATUS_SUSPENDED) {
+		return;
+	}
+
+	zend_object *exception = EG(exception);
+	EG(exception) = NULL;
+
+	fiber->status = ZEND_FIBER_STATUS_SHUTDOWN;
 
-		fiber->status = ZEND_FIBER_STATUS_SHUTDOWN;
+	zend_fiber_switch_to(fiber);
 
-		zend_fiber_switch_to(fiber);
+	if (EG(exception)) {
+		zend_exception_set_previous(EG(exception), exception);
 
+		if (EG(flags) & EG_FLAGS_IN_SHUTDOWN) {
+			zend_exception_error(EG(exception), E_ERROR);
+		}
+	} else {
 		EG(exception) = exception;
 	}
 }
@@ -471,7 +479,7 @@ ZEND_METHOD(Fiber, suspend)
 	}
 
 	if (UNEXPECTED(fiber->status == ZEND_FIBER_STATUS_SHUTDOWN)) {
-		zend_throw_error(zend_ce_fiber_error, "Cannot suspend in a force closed fiber");
+		zend_throw_error(zend_ce_fiber_error, "Cannot suspend in a force-closed fiber");
 		RETURN_THROWS();
 	}