JIT: Fixed reference-counting inference

Author: dstogov

ext/opcache/Optimizer/zend_inference.c

@@ -2147,7 +2147,7 @@ static uint32_t binary_op_result_type(
 		case ZEND_BW_AND:
 		case ZEND_BW_XOR:
 			if ((t1_type & MAY_BE_STRING) && (t2_type & MAY_BE_STRING)) {
-				tmp |= MAY_BE_STRING | MAY_BE_RC1;
+				tmp |= MAY_BE_STRING | MAY_BE_RC1 | MAY_BE_RCN;
 			}
 			if ((t1_type & ~MAY_BE_STRING) || (t2_type & ~MAY_BE_STRING)) {
 				tmp |= MAY_BE_LONG;

ext/opcache/tests/jit/and_001.phpt

@@ -0,0 +1,17 @@
+--TEST--
+JIT BW_AND: 001 (emty string)
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.file_update_protection=0
+opcache.jit_buffer_size=1M
+--FILE--
+<?php
+$a = [];
+$b = "";
+$a["" & $b] *= 3;
+?>
+DONE
+--EXPECTF--
+Warning: Undefined array key "" in %sand_001.php on line 4
+DONE