From: Nikita Popov <nikita.ppv@gmail.com>
Date: Fri, 3 Apr 2020 08:06:41 +0000 (+0200)
Subject: Fixed bug #78434
X-Git-Tag: php-7.4.7RC1~73
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=823a956855c1f38ed8ee888bf248917e28d40314;p=php

Fixed bug #78434

The DO_INIT flag, which will skip the first resume on a primed
generator, should always be set when starting to yield from a
new generator, not only when the yield from happens during priming.
---

diff --git a/NEWS b/NEWS
index 67d71eca64..dd770268ae 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,9 @@ PHP                                                                        NEWS
 
 ?? ??? ????, PHP 7.4.6
 
+- Core:
+  . Fixed bug #78434 (Generator yields no items after valid() call). (Nikita)
+
 - DOM:
   . Fixed bug #78221 (DOMNode::normalize() doesn't remove empty text nodes).
     (cmb)
diff --git a/Zend/tests/generators/bug78434.phpt b/Zend/tests/generators/bug78434.phpt
new file mode 100644
index 0000000000..dd9351e168
--- /dev/null
+++ b/Zend/tests/generators/bug78434.phpt
@@ -0,0 +1,27 @@
+--TEST--
+Bug #78434: Generator skips first item after valid() call
+--FILE--
+<?php
+
+$function = function () {
+    yield 0;
+};
+
+$wrapper = function () use ($function) {
+    $generator = $function();
+    $generator->valid();
+    yield from $generator;
+
+    $generator = $function();
+    $generator->valid();
+    yield from $generator;
+};
+
+foreach ($wrapper() as $value) {
+    echo $value, "\n";
+}
+
+?>
+--EXPECT--
+0
+0
diff --git a/Zend/tests/generators/yield_from_multi_tree.phpt b/Zend/tests/generators/yield_from_multi_tree.phpt
index 9bec138149..808d693eae 100644
--- a/Zend/tests/generators/yield_from_multi_tree.phpt
+++ b/Zend/tests/generators/yield_from_multi_tree.phpt
@@ -10,9 +10,6 @@ function from($levels) {
 }
 
 function gen($gen, $level) {
-	if ($level % 2) {
-		yield $gen->current();
-	}
 	yield from $gen;
 }
 
diff --git a/Zend/zend_generators.c b/Zend/zend_generators.c
index 7031e9a810..9d8546f518 100644
--- a/Zend/zend_generators.c
+++ b/Zend/zend_generators.c
@@ -609,6 +609,7 @@ void zend_generator_yield_from(zend_generator *generator, zend_generator *from)
 	generator->node.parent = from;
 	zend_generator_get_current(generator);
 	GC_DELREF(&from->std);
+	generator->flags |= ZEND_GENERATOR_DO_INIT;
 }
 
 ZEND_API zend_generator *zend_generator_update_current(zend_generator *generator, zend_generator *leaf)
@@ -785,6 +786,7 @@ try_again:
 
 	if (UNEXPECTED((orig_generator->flags & ZEND_GENERATOR_DO_INIT) != 0 && !Z_ISUNDEF(generator->value))) {
 		/* We must not advance Generator if we yield from a Generator being currently run */
+		orig_generator->flags &= ~ZEND_GENERATOR_DO_INIT;
 		return;
 	}
 
@@ -864,15 +866,15 @@ try_again:
 			goto try_again;
 		}
 	}
+
+	orig_generator->flags &= ~ZEND_GENERATOR_DO_INIT;
 }
 /* }}} */
 
 static inline void zend_generator_ensure_initialized(zend_generator *generator) /* {{{ */
 {
 	if (UNEXPECTED(Z_TYPE(generator->value) == IS_UNDEF) && EXPECTED(generator->execute_data) && EXPECTED(generator->node.parent == NULL)) {
-		generator->flags |= ZEND_GENERATOR_DO_INIT;
 		zend_generator_resume(generator);
-		generator->flags &= ~ZEND_GENERATOR_DO_INIT;
 		generator->flags |= ZEND_GENERATOR_AT_FIRST_YIELD;
 	}
 }