Fixed bug #76711 (OPcache enabled triggers false-positive "Illegal string offset")

Author: dstogov

NEWS

@@ -14,6 +14,10 @@ PHP                                                                        NEWS
   . Fixed bug #76901 (method_exists on SPL iterator passthrough method corrupts
     memory). (Nikita)
 
+- Opcache:
+  . Fixed bug #76711 (OPcache enabled triggers false-positive "Illegal string
+   offset"). (Dmitry)
+
 - Standard:
   . Fixed bug #75533 (array_reduce is slow when $carry is large array).
     (Manabu Matsui)

ext/opcache/Optimizer/compact_literals.c

@@ -378,6 +378,7 @@ void zend_optimizer_compact_literals(zend_op_array *op_array, zend_optimizer_ctx
 						} else {
 							map[i] = j;
 							ZVAL_LONG(&zv, j);
+							Z_EXTRA(op_array->literals[i]) = 0; /* allow merging with FETCH_DIM_... */
 							zend_hash_index_add_new(&hash, Z_LVAL(op_array->literals[i]), &zv);
 							if (i != j) {
 								op_array->literals[j] = op_array->literals[i];

ext/opcache/tests/bug76711.phpt

@@ -0,0 +1,19 @@
+--TEST--
+Bug #76711 OPcache enabled triggers false-positive "Illegal string offset"
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.optimization_level=-1
+--SKIPIF--
+<?php require_once('skipif.inc'); ?>
+--FILE--
+<?php
+function test($foo) {
+    var_dump(0);
+    var_dump($foo[0]);
+}
+test("str");
+?>
+--EXPECT--
+int(0)
+string(1) "s"