From 65d70a6b6afcd141f2d9c493840bfdeb2a607b9d Mon Sep 17 00:00:00 2001
From: Ilija Tovilo <ilija.tovilo@me.com>
Date: Mon, 17 Mar 2025 23:01:22 +0100
Subject: [PATCH] Fix parser expectation error for amp token

Currently, this is only handled for the "unexpected token" part of the
message, but not the "expected" part.

Fixes GH-18026
---
 Zend/tests/gh18026.phpt     | 12 ++++++++++++
 Zend/zend_language_parser.y |  8 ++++++++
 2 files changed, 20 insertions(+)
 create mode 100644 Zend/tests/gh18026.phpt

diff --git a/Zend/tests/gh18026.phpt b/Zend/tests/gh18026.phpt
new file mode 100644
index 000000000000..0e33e349b12f
--- /dev/null
+++ b/Zend/tests/gh18026.phpt
@@ -0,0 +1,12 @@
+--TEST--
+GH-18026: Confusing "amp" reference in parser error
+--FILE--
+<?php
+
+class Demo {
+    private (set) mixed $v1;
+}
+
+?>
+--EXPECTF--
+Parse error: syntax error, unexpected token ")", expecting token "&" in %s on line %d
diff --git a/Zend/zend_language_parser.y b/Zend/zend_language_parser.y
index c671b3a295e5..1f117d142c15 100644
--- a/Zend/zend_language_parser.y
+++ b/Zend/zend_language_parser.y
@@ -1819,6 +1819,14 @@ static YYSIZE_T zend_yytnamerr(char *yyres, const char *yystr)
 		return sizeof("\"\\\"")-1;
 	}
 
+	/* We used "amp" as a dummy label to avoid a duplicate token literal warning. */
+	if (strcmp(toktype, "\"amp\"") == 0) {
+		if (yyres) {
+			yystpcpy(yyres, "token \"&\"");
+		}
+		return sizeof("token \"&\"")-1;
+	}
+
 	/* Strip off the outer quote marks */
 	if (toktype_len >= 2 && *toktype == '"') {
 		toktype++;