From 40719c56dbb3461549869d213c9dd8f1b116098e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Wed, 28 Nov 2012 08:48:48 +0100
Subject: [PATCH] Fixed #4183 (false positive with method named c_str())

---
 lib/checkstl.cpp | 7 +++++--
 test/teststl.cpp | 9 +++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/lib/checkstl.cpp b/lib/checkstl.cpp
index bb0d3c560..ccab39baa 100644
--- a/lib/checkstl.cpp
+++ b/lib/checkstl.cpp
@@ -1194,8 +1194,11 @@ void CheckStl::string_c_str()
                         tok2 = tok->next()->link();
                     else
                         tok2 = tok2->previous();
-                    if (tok2 && Token::simpleMatch(tok2->tokAt(-4), ". c_str ( )"))
-                        string_c_strParam(tok, i->second);
+                    if (tok2 && Token::simpleMatch(tok2->tokAt(-4), ". c_str ( )")) {
+                        const Variable* var = symbolDatabase->getVariableFromVarId(tok2->tokAt(-5)->varId());
+                        if (var && Token::Match(var->typeStartToken(), "const| std :: string|wstring"))
+                            string_c_strParam(tok, i->second);
+                    }
                 }
             }
 
diff --git a/test/teststl.cpp b/test/teststl.cpp
index c5ffaa442..3d45eb4cc 100644
--- a/test/teststl.cpp
+++ b/test/teststl.cpp
@@ -1864,6 +1864,15 @@ private:
               "    return hello().c_str();\n"
               "}\n");
         ASSERT_EQUALS("[test.cpp:11]: (error) Dangerous usage of c_str(). The value returned by c_str() is invalid after this call.\n", errout.str());
+
+        // #4183 - using MyStringClass.c_str()
+        check("void a(const std::string &str);\n"
+              "\n"
+              "void b() {\n"
+              "    MyStringClass s;\n"
+              "    a(s.c_str());\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void autoPointer() {