Skip bailout for unwind and graceful exit in zend_throw_exception_internal()

Fixes GH-18619

Author: iluuu1994

Zend/tests/gh18619.phpt

@@ -0,0 +1,20 @@
+--TEST--
+Gh-18619: exit() from error handler should not trigger bailout
+--FILE--
+<?php
+
+function foo($e) {
+    exit;
+}
+
+set_exception_handler('foo');
+
+register_shutdown_function(function () {
+    var_dump(set_exception_handler(null));
+});
+
+throw new Error();
+
+?>
+--EXPECT--
+string(3) "foo"

Zend/zend_exceptions.c

@@ -210,9 +210,13 @@ ZEND_API ZEND_COLD void zend_throw_exception_internal(zend_object *exception) /*
 			return;
 		}
 		if (EG(exception)) {
-			if (Z_TYPE(EG(user_exception_handler)) != IS_UNDEF
-			 && !zend_is_unwind_exit(EG(exception))
-			 && !zend_is_graceful_exit(EG(exception))) {
+			if (zend_is_unwind_exit(EG(exception))
+			 || zend_is_graceful_exit(EG(exception))) {
+				/* Stack is fully unwound, clear the unwind exit. */
+				zend_exception_error(EG(exception), E_ERROR);
+				return;
+			}
+			if (Z_TYPE(EG(user_exception_handler)) != IS_UNDEF) {
 				zend_user_exception_handler();
 				if (EG(exception)) {
 					zend_exception_error(EG(exception), E_ERROR);