Argument unpacking with Traversables and non-integer keys.

Changed error message, added UPGRADING note and test.

Author: dstogov

UPGRADING

@@ -80,6 +80,19 @@ Core:
     note that reading and writing a value inside a single expression remains
     undefined behavior and may change again in the future.
 
+  . Argument unpacking stopped working with Traversables with non-integer keys.
+    The following code worked in PHP 7.0-7.2 by accident.
+
+        function foo(...$args) {
+            var_dump($args);
+        }
+        function gen() {
+            yield 1.23 => 123;
+        }
+        foo(...gen());
+
+    Now it generates an exception.
+
 BCMath:
   . All warnings thrown by BCMath functions are now using PHP's error handling.
     Formerly some warnings have directly been written to stderr.

Zend/tests/arg_unpack/non_integer_keys.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Argument unpacking does not work with non-integer keys
+--FILE--
+<?php
+function foo(...$args) {
+	var_dump($args);
+}
+function gen() {
+	yield 1.23 => 123;
+	yield "2.34" => 234;
+}
+
+try {
+	foo(...gen());
+} catch (Error $ex) {
+	echo "Exception: " . $ex->getMessage() . "\n";
+}
+
+?>
+--EXPECT--
+Exception: Cannot unpack Traversable with non-integer keys

Zend/zend_vm_def.h

@@ -4522,10 +4522,11 @@ ZEND_VM_C_LABEL(send_again):
 					}
 
 					if (UNEXPECTED(Z_TYPE(key) != IS_LONG)) {
-						ZEND_ASSERT(Z_TYPE(key) == IS_STRING);
 						zend_throw_error(NULL,
-							"Cannot unpack Traversable with string keys");
-						zval_ptr_dtor_str(&key);
+							(Z_TYPE(key) == IS_STRING) ?
+								"Cannot unpack Traversable with string keys" :
+								"Cannot unpack Traversable with non-integer keys");
+						zval_ptr_dtor(&key);
 						break;
 					}
 				}

Zend/zend_vm_execute.h

@@ -1359,10 +1359,11 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_SEND_UNPACK_SPEC_HANDLER(ZEND_
 					}
 
 					if (UNEXPECTED(Z_TYPE(key) != IS_LONG)) {
-						ZEND_ASSERT(Z_TYPE(key) == IS_STRING);
 						zend_throw_error(NULL,
-							"Cannot unpack Traversable with string keys");
-						zval_ptr_dtor_str(&key);
+							(Z_TYPE(key) == IS_STRING) ?
+								"Cannot unpack Traversable with string keys" :
+								"Cannot unpack Traversable with non-integer keys");
+						zval_ptr_dtor(&key);
 						break;
 					}
 				}