Merge branch 'PHP-8.1'

* PHP-8.1:
  Handle holes in zend_get_opcode_id()

Author: nikic

Zend/zend_vm_gen.php

@@ -2651,7 +2651,8 @@ function gen_vm($def, $skel) {
     fputs($f, "ZEND_API zend_uchar zend_get_opcode_id(const char *name, size_t length) {\n");
     fputs($f, "\tzend_uchar opcode;\n");
     fputs($f, "\tfor (opcode = 0; opcode < (sizeof(zend_vm_opcodes_names) / sizeof(zend_vm_opcodes_names[0])) - 1; opcode++) {\n");
-    fputs($f, "\t\tif (strncmp(zend_vm_opcodes_names[opcode], name, length) == 0) {\n");
+    fputs($f, "\t\tconst char *opcode_name = zend_vm_opcodes_names[opcode];\n");
+    fputs($f, "\t\tif (opcode_name && strncmp(opcode_name, name, length) == 0) {\n");
     fputs($f, "\t\t\treturn opcode;\n");
     fputs($f, "\t\t}\n");
     fputs($f, "\t}\n");

Zend/zend_vm_opcodes.c

@@ -449,7 +449,8 @@ ZEND_API uint32_t ZEND_FASTCALL zend_get_opcode_flags(zend_uchar opcode) {
 ZEND_API zend_uchar zend_get_opcode_id(const char *name, size_t length) {
 	zend_uchar opcode;
 	for (opcode = 0; opcode < (sizeof(zend_vm_opcodes_names) / sizeof(zend_vm_opcodes_names[0])) - 1; opcode++) {
-		if (strncmp(zend_vm_opcodes_names[opcode], name, length) == 0) {
+		const char *opcode_name = zend_vm_opcodes_names[opcode];
+		if (opcode_name && strncmp(opcode_name, name, length) == 0) {
 			return opcode;
 		}
 	}