From c13f8fd35f02555d137b88cc5a9b2716e8723617 Mon Sep 17 00:00:00 2001
From: Alexandre Daubois <alex.daubois@gmail.com>
Date: Fri, 9 Jan 2026 11:33:02 +0100
Subject: [PATCH] Core: fix missing deprecation when accessing null array key
 with JIT

---
 NEWS                                       |  2 ++
 Zend/Optimizer/sccp.c                      | 12 ++++++++++++
 ext/opcache/tests/jit/fetch_dim_r_001.phpt |  4 +++-
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index 5a03492c24203..a57698930b811 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,8 @@ PHP                                                                        NEWS
     (henderkes)
   . Fixed bug GH-20767 (build failure with musttail/preserve_none feature
     on macOs). (David Carlier)
+  . Fix deprecation now showing when accessing null key of an array with JIT.
+    (alexandre-daubois)
 
 - MbString:
   . Fixed bug GH-20833 (mb_str_pad() divide by zero if padding string is
diff --git a/Zend/Optimizer/sccp.c b/Zend/Optimizer/sccp.c
index 7e2fc2db1b256..643e79d68ba35 100644
--- a/Zend/Optimizer/sccp.c
+++ b/Zend/Optimizer/sccp.c
@@ -1535,6 +1535,12 @@ static void sccp_visit_instr(scdf_ctx *scdf, zend_op *opline, zend_ssa_op *ssa_o
 			SKIP_IF_TOP(op1);
 			SKIP_IF_TOP(op2);
 
+			if (op2 && Z_TYPE_P(op2) == IS_NULL) {
+				/* Emits deprecation at run-time. */
+				SET_RESULT_BOT(result);
+				break;
+			}
+
 			if (ct_eval_fetch_dim(&zv, op1, op2, (opline->opcode != ZEND_FETCH_LIST_R)) == SUCCESS) {
 				SET_RESULT(result, &zv);
 				zval_ptr_dtor_nogc(&zv);
@@ -1546,6 +1552,12 @@ static void sccp_visit_instr(scdf_ctx *scdf, zend_op *opline, zend_ssa_op *ssa_o
 			SKIP_IF_TOP(op1);
 			SKIP_IF_TOP(op2);
 
+			if (op2 && Z_TYPE_P(op2) == IS_NULL) {
+				/* Emits deprecation at run-time. */
+				SET_RESULT_BOT(result);
+				break;
+			}
+
 			if (ct_eval_isset_dim(&zv, opline->extended_value, op1, op2) == SUCCESS) {
 				SET_RESULT(result, &zv);
 				zval_ptr_dtor_nogc(&zv);
diff --git a/ext/opcache/tests/jit/fetch_dim_r_001.phpt b/ext/opcache/tests/jit/fetch_dim_r_001.phpt
index 3ff56263db683..819ec7edca655 100644
--- a/ext/opcache/tests/jit/fetch_dim_r_001.phpt
+++ b/ext/opcache/tests/jit/fetch_dim_r_001.phpt
@@ -30,7 +30,7 @@ function foo() {
 }
 foo();
 ?>
---EXPECT--
+--EXPECTF--
 int(1)
 int(3)
 int(2)
@@ -38,6 +38,8 @@ int(1)
 int(3)
 int(1)
 int(2)
+
+Deprecated: Using null as an array offset is deprecated, use an empty string instead in %s on line %d
 int(4)
 int(5)
 int(5)