Fixed bug #79927

We need to unset the AT_FIRST_YIELD flag when yielding from an
array as well.

In the interest of being conservative, I'm applying this only to
PHP 8.

Author: nikic

NEWS

@@ -21,6 +21,8 @@ PHP                                                                        NEWS
     exit value in CLI). (Nikita)
   . Fixed bug #62294 (register_shutdown_function() does not correctly handle
     exit code). (Nikita)
+  . Fixed bug #79927 (Generator doesn't throw exception after multiple yield
+    from iterable). (Nikita)
 
 - Date:
   . Fixed bug #60302 (DateTime::createFromFormat should new static(), not new

Zend/tests/bug79927.phpt

@@ -0,0 +1,31 @@
+--TEST--
+Bug #79927: Generator doesn't throw exception after multiple yield from iterable
+--FILE--
+<?php
+
+$generator = (function () {
+    yield from [1, 2, 3];
+})();
+
+$generator->next();
+$generator->next();
+try {
+    $generator->rewind();
+} catch (Exception $e) {
+    echo $e->getMessage(), "\n";
+}
+echo $generator->current(), "\n";
+
+$generator2 = (function () {
+    yield from [];
+    yield 4;
+})();
+$generator2->current();
+$generator2->rewind();
+echo $generator2->current(), "\n";
+
+?>
+--EXPECT--
+Cannot rewind a generator that was already run
+3
+4

Zend/zend_generators.c

@@ -731,6 +731,9 @@ ZEND_API void zend_generator_resume(zend_generator *orig_generator) /* {{{ */
 		return;
 	}
 
+	/* Drop the AT_FIRST_YIELD flag */
+	orig_generator->flags &= ~ZEND_GENERATOR_AT_FIRST_YIELD;
+
 	if (UNEXPECTED(!Z_ISUNDEF(generator->values))) {
 		if (EXPECTED(zend_generator_get_next_delegated_value(generator) == SUCCESS)) {
 			orig_generator->flags &= ~ZEND_GENERATOR_DO_INIT;
@@ -740,9 +743,6 @@ ZEND_API void zend_generator_resume(zend_generator *orig_generator) /* {{{ */
 		 * after the "yield from" expression. */
 	}
 
-	/* Drop the AT_FIRST_YIELD flag */
-	orig_generator->flags &= ~ZEND_GENERATOR_AT_FIRST_YIELD;
-
 	{
 		/* Backup executor globals */
 		zend_execute_data *original_execute_data = EG(current_execute_data);