From 3976f9c751d37ed76d7a31acc80a58f0f56f755a Mon Sep 17 00:00:00 2001
From: chrchr-github <noreply@github.com>
Date: Mon, 29 Jun 2026 19:19:02 +0200
Subject: [PATCH]  Fix #14876 Nullptr dereference in usingMatch()

---
 lib/tokenize.cpp           | 3 +++
 test/testsimplifyusing.cpp | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 7379957804f..4167aa71cec 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -2720,6 +2720,9 @@ namespace {
             return false;
         }
 
+        if (!tok->tokAt(-1))
+            return false;
+
         // skip other using with this name
         if (tok1->strAt(-1) == "using") {
             // fixme: this is wrong
diff --git a/test/testsimplifyusing.cpp b/test/testsimplifyusing.cpp
index 7359613510f..d0f40dce372 100644
--- a/test/testsimplifyusing.cpp
+++ b/test/testsimplifyusing.cpp
@@ -77,6 +77,7 @@ class TestSimplifyUsing : public TestFixture {
         TEST_CASE(simplifyUsing37);
         TEST_CASE(simplifyUsing38);
         TEST_CASE(simplifyUsing39);
+        TEST_CASE(simplifyUsing40);
 
         TEST_CASE(simplifyUsing8970);
         TEST_CASE(simplifyUsing8971);
@@ -939,6 +940,13 @@ class TestSimplifyUsing : public TestFixture {
         ASSERT_EQUALS("", errout_str());
     }
 
+    void simplifyUsing40() {
+        const char code[] = "uint8_t f();\n" // #14876
+                            "using ::std::uint8_t;";
+        const char expected[] = "uint8_t f ( ) ;";
+        ASSERT_EQUALS(expected, tok(code));
+    }
+
     void simplifyUsing8970() {
         const char code[] = "using V = std::vector<int>;\n"
                             "struct A {\n"