Ensure end handlers fire only once for fatals

Author: SammyK

Zend/zend.c

@@ -1329,6 +1329,11 @@ static ZEND_COLD void zend_error_impl(
 		do {
 			if (ex->func->type != ZEND_INTERNAL_FUNCTION) {
 				zend_observer_fcall_end(ex, NULL);
+				/* If an extension catches a fatal error and raises another one, the
+				 * observer end handlers will fire more than once. This requires us
+				 * to "unobserve" the functions after the end handlers have fired the
+				 * first time. */
+				zend_observer_fcall_unobserve(ex->func);
 			}
 		} while ((ex = ex->prev_execute_data) != NULL);
 	}

Zend/zend_observer.c

@@ -210,6 +210,15 @@ ZEND_API void ZEND_FASTCALL zend_observer_fcall_end(
 	}
 }
 
+ZEND_API void zend_observer_fcall_unobserve(zend_function *func)
+{
+	if (ZEND_OBSERVER_ENABLED
+		&& ZEND_OBSERVABLE_FN(func->common.fn_flags)
+		&& ZEND_OBSERVER_DATA(&func->op_array)) {
+		ZEND_OBSERVER_DATA(&func->op_array) = ZEND_OBSERVER_NOT_OBSERVED;
+	}
+}
+
 ZEND_API void zend_observer_error_register(zend_observer_error_cb cb)
 {
 	zend_llist_add_element(&zend_observer_error_callbacks, &cb);

Zend/zend_observer.h

@@ -70,6 +70,8 @@ ZEND_API void ZEND_FASTCALL zend_observer_fcall_end(
 	zend_execute_data *execute_data,
 	zval *return_value);
 
+ZEND_API void zend_observer_fcall_unobserve(zend_function *func);
+
 typedef void (*zend_observer_error_cb)(int type, const char *error_filename, uint32_t error_lineno, zend_string *message);
 
 ZEND_API void zend_observer_error_register(zend_observer_error_cb callback);

ext/zend_test/tests/observer_error_04.phpt

@@ -0,0 +1,43 @@
+--TEST--
+Observer: fatal errors caught with zend_try will fire end handlers once
+--SKIPIF--
+<?php if (!extension_loaded('zend-test')) die('skip: zend-test extension required'); ?>
+<?php if (!extension_loaded('soap')) die('skip: soap extension required'); ?>
+--INI--
+zend_test.observer.enabled=1
+zend_test.observer.observe_all=1
+zend_test.observer.show_return_value=1
+--FILE--
+<?php
+function foo()
+{
+    try {
+        // ext/soap catches a fatal error and then throws an exception
+        $client = new SoapClient('foo');
+    } catch (SoapFault $e) {
+        echo $e->getMessage() . PHP_EOL;
+    }
+}
+
+function main()
+{
+    foo();
+}
+
+main();
+
+echo 'Done.' . PHP_EOL;
+?>
+--EXPECTF--
+<!-- init '%s/observer_error_%d.php' -->
+<file '%s/observer_error_%d.php'>
+  <!-- init main() -->
+  <main>
+    <!-- init foo() -->
+    <foo>
+    </foo:NULL>
+  </main:NULL>
+</file '%s/observer_error_%d.php'>
+SOAP-ERROR: Parsing WSDL: Couldn't load from 'foo' : failed to load external entity "foo"
+
+Done.