Fix bug 81159

Zend/tests/bug81159.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Bug #81159: Object to int warning when using an object as a string offset
+--FILE--
+<?php
+
+$s = 'Hello';
+$o = new stdClass();
+try {
+    $s[$o] = 'A';
+} catch (\Throwable $e) {
+    echo $e->getMessage(), "\n";
+}
+try {
+    var_dump($s[$o]);
+} catch (\Throwable $e) {
+    echo $e->getMessage(), "\n";
+}
+?>
+--EXPECT--
+Cannot access offset of type stdClass on string
+Cannot access offset of type stdClass on string

Zend/tests/offset_string.phpt

@@ -68,8 +68,6 @@ string(1) "i"
 Warning: String offset cast occurred in %s on line %d
 string(1) "S"
 Cannot access offset of type resource on string
-
-Warning: Object of class stdClass could not be converted to int in %s on line %d
 Cannot access offset of type stdClass on string
 Cannot access offset of type array on string
 Done

Zend/zend_execute.c

@@ -1384,7 +1384,7 @@ static zend_never_inline zend_long zend_check_string_offset(zval *dim, int type
 					return offset;
 				}
 				zend_illegal_string_offset(dim);
-				break;
+				return 0;
 			}
 			case IS_UNDEF:
 				ZVAL_UNDEFINED_OP2();
@@ -1399,7 +1399,7 @@ static zend_never_inline zend_long zend_check_string_offset(zval *dim, int type
 				goto try_again;
 			default:
 				zend_illegal_string_offset(dim);
-				break;
+				return 0;
 		}
 
 		offset = zval_get_long_func(dim);
@@ -2384,7 +2384,8 @@ static zend_always_inline void zend_fetch_dimension_address_read(zval *result, z
 						return;
 					}
 					zend_illegal_string_offset(dim);
-					break;
+					ZVAL_NULL(result);
+					return;
 				}
 				case IS_UNDEF:
 					ZVAL_UNDEFINED_OP2();
@@ -2401,7 +2402,8 @@ static zend_always_inline void zend_fetch_dimension_address_read(zval *result, z
 					goto try_string_offset;
 				default:
 					zend_illegal_string_offset(dim);
-					break;
+					ZVAL_NULL(result);
+					return;
 			}
 
 			offset = zval_get_long_func(dim);