From 3e22ef1c21f19548b2b2b7c35aa70840deff8308 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Thu, 4 Apr 2024 17:45:34 +0200
Subject: [PATCH] Fix #12586 Crash in getReallocFuncInfo() with namespace alias
 (#6230)

---
 lib/tokenize.cpp            |  2 ++
 test/testsimplifytokens.cpp | 13 +++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 4dcd5b6fad5..2d3c97e418a 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -10605,6 +10605,8 @@ void Tokenizer::simplifyNamespaceAliases()
                     }
 
                     if (tok2->strAt(1) == "::" && !alreadyHasNamespace(tokNameStart, tokNameEnd, tok2)) {
+                        if (Token::simpleMatch(tok2->tokAt(-1), "::") && tokNameStart->str() == "::")
+                            tok2->deletePrevious();
                         tok2->str(tokNameStart->str());
                         Token * tok3 = tokNameStart;
                         while (tok3 != tokNameEnd) {
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index 3a14888eef4..0f46f1e3998 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -113,6 +113,7 @@ class TestSimplifyTokens : public TestFixture {
         TEST_CASE(simplifyNestedNamespace);
         TEST_CASE(simplifyNamespaceAliases1);
         TEST_CASE(simplifyNamespaceAliases2); // ticket #10281
+        TEST_CASE(simplifyNamespaceAliases3);
 
         TEST_CASE(simplifyKnownVariables2);
         TEST_CASE(simplifyKnownVariables3);
@@ -1502,6 +1503,18 @@ class TestSimplifyTokens : public TestFixture {
                           "}"));
     }
 
+    void simplifyNamespaceAliases3() {
+        ASSERT_EQUALS("namespace N { namespace O { int g ( ) ; } } " // #12586
+                      "void f ( ) { "
+                      "int s ; s = 3 * :: N :: O :: g ( ) ; "
+                      "}",
+                      tok("namespace N { namespace O { int g(); } }\n"
+                          "namespace _n = ::N::O;\n"
+                          "void f() {\n"
+                          "    int s = 3 * ::_n::g();\n"
+                          "}\n"));
+    }
+
 #define simplifyKnownVariables(code) simplifyKnownVariables_(code, __FILE__, __LINE__)
     std::string simplifyKnownVariables_(const char code[], const char* file, int line) {
         Tokenizer tokenizer(settings0, this);