Throw from MultipleIterator::key/current() for invalid iterator

Calling current()/key() on an invalid iterator is an error
condition. Throw instead of returning false.

Author: nikic

ext/spl/spl_observer.c

@@ -1097,7 +1097,9 @@ static void spl_multiple_iterator_get_all(spl_SplObjectStorage *intern, int get_
 
 	num_elements = zend_hash_num_elements(&intern->storage);
 	if (num_elements < 1) {
-		RETURN_FALSE;
+		zend_throw_exception_ex(spl_ce_RuntimeException, 0, "Called %s() on an invalid iterator",
+			get_type == SPL_MULTIPLE_ITERATOR_GET_ALL_CURRENT ? "current" : "key");
+		RETURN_THROWS();
 	}
 
 	array_init_size(return_value, num_elements);

ext/spl/spl_observer.stub.php

@@ -58,7 +58,7 @@ public function valid() {}
     /** @return int */
     public function key() {}
 
-    /** @return object|null */
+    /** @return object */
     public function current() {}
 
     /** @return void */
@@ -141,10 +141,10 @@ public function rewind() {}
     /** @return bool */
     public function valid() {}
 
-    /** @return array|false */
+    /** @return array */
     public function key() {}
 
-    /** @return array|false */
+    /** @return array */
     public function current() {}
 
     /** @return void */

ext/spl/spl_observer_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 89437500594aa41fa5cd36f31de07ad65f2bf408 */
+ * Stub hash: b82f26b4c1340b58c0faa31c5e14fef4c9778928 */
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_SplObserver_update, 0, 0, 1)
 	ZEND_ARG_OBJ_INFO(0, subject, SplSubject, 0)

ext/spl/tests/multiple_iterator_001.phpt

@@ -13,7 +13,16 @@ echo "-- Default flags, no iterators --\n";
 foreach($m as $value) {
     var_dump($value);
 }
-var_dump($m->current());
+try {
+    var_dump($m->current());
+} catch (RuntimeException $e) {
+    echo $e->getMessage(), "\n";
+}
+try {
+    var_dump($m->key());
+} catch (RuntimeException $e) {
+    echo $e->getMessage(), "\n";
+}
 
 $m->attachIterator($iter1);
 $m->attachIterator($iter2);
@@ -105,7 +114,8 @@ foreach($m as $key => $value) {
 ?>
 --EXPECTF--
 -- Default flags, no iterators --
-bool(false)
+Called current() on an invalid iterator
+Called key() on an invalid iterator
 -- Default flags, MultipleIterator::MIT_NEED_ALL | MultipleIterator::MIT_KEYS_NUMERIC --
 bool(true)
 array(3) {