From 73a92964ffd80ae907314b8202ed99716e4ba918 Mon Sep 17 00:00:00 2001
From: Bob Weinand <bobwei9@hotmail.com>
Date: Wed, 25 Nov 2015 09:49:39 +0100
Subject: [PATCH] Fixed bug #70965 (yield from with a common iterator primes
 too much)

---
 Zend/tests/generators/bug70965.phpt | 32 +++++++++++++++++++++++++++++
 Zend/zend_generators.c              | 10 ++++-----
 2 files changed, 37 insertions(+), 5 deletions(-)
 create mode 100644 Zend/tests/generators/bug70965.phpt

diff --git a/Zend/tests/generators/bug70965.phpt b/Zend/tests/generators/bug70965.phpt
new file mode 100644
index 0000000000..4ed34fd640
--- /dev/null
+++ b/Zend/tests/generators/bug70965.phpt
@@ -0,0 +1,32 @@
+--TEST--
+Bug #70965 (yield from with a common iterator primes too much)
+--FILE--
+<?php
+
+function it() {
+    yield from [1, 2, 3, 4, 5];
+}
+
+function bar($g) {
+    yield from $g;
+}
+
+$gen = it();
+$gens[] = bar($gen);
+$gens[] = bar($gen);
+
+do {
+    foreach($gens as $g) {
+        var_dump($g->current());
+        $gen->next();
+    }
+} while ($gen->valid());
+
+?>
+--EXPECT--
+int(1)
+int(2)
+int(3)
+int(4)
+int(5)
+int(5)
diff --git a/Zend/zend_generators.c b/Zend/zend_generators.c
index 5502633570..9ef63df8d6 100644
--- a/Zend/zend_generators.c
+++ b/Zend/zend_generators.c
@@ -621,6 +621,11 @@ try_again:
 		return;
 	}
 
+	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 */
+		return;
+	}
+
 	if (UNEXPECTED(!Z_ISUNDEF(generator->values))) {
 		if (EXPECTED(zend_generator_get_next_delegated_value(generator) == SUCCESS)) {
 			return;
@@ -629,11 +634,6 @@ try_again:
 		 * after the "yield from" expression. */
 	}
 
-	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 */
-		return;
-	}
-
 	/* Drop the AT_FIRST_YIELD flag */
 	orig_generator->flags &= ~ZEND_GENERATOR_AT_FIRST_YIELD;
 
-- 
2.40.0