Fix #419 (missleading buffer overrun)

http://sourceforge.net/apps/trac/cppcheck/ticket/419

src/checkbufferoverrun.cpp

@@ -67,6 +67,11 @@ void CheckBufferOverrun::bufferOverrun(const Token *tok)
     reportError(tok, Severity::possibleError, "bufferOverrun", "Buffer overrun");
 }
 
+void CheckBufferOverrun::dangerousStdCin(const Token *tok)
+{
+    reportError(tok, Severity::possibleError, "dangerousStdCin", "Dangerous usage of std::cin, possible buffer overrun");
+}
+
 void CheckBufferOverrun::strncatUsage(const Token *tok)
 {
     reportError(tok, Severity::possibleError, "strncatUsage", "Dangerous usage of strncat. Tip: the 3rd parameter means maximum number of characters to append");
@@ -514,7 +519,7 @@ void CheckBufferOverrun::checkScope(const Token *tok, const char *varname[], con
         // cin..
         if (varid > 0 && Token::Match(tok, "cin >> %varid% ;", varid))
         {
-            bufferOverrun(tok);
+            dangerousStdCin(tok);
         }
 
         // Function call..

src/checkbufferoverrun.h

@@ -75,6 +75,7 @@ private:
     void arrayIndexOutOfBounds(const Token *tok);
     void arrayIndexOutOfBounds();
     void bufferOverrun(const Token *tok);
+    void dangerousStdCin(const Token *tok);
     void strncatUsage(const Token *tok);
     void outOfBounds(const Token *tok, const std::string &what);
     void sizeArgumentAsChar(const Token *tok);
@@ -83,6 +84,7 @@ private:
     {
         arrayIndexOutOfBounds(0);
         bufferOverrun(0);
+        dangerousStdCin(0);
         strncatUsage(0);
         outOfBounds(0, "index");
         sizeArgumentAsChar(0);

test/testbufferoverrun.cpp

@@ -827,7 +827,7 @@ private:
               "    char str[10];\n"
               "    cin >> str;\n"
               "}\n");
-        ASSERT_EQUALS("[test.cpp:4]: (possible error) Buffer overrun\n", errout.str());
+        ASSERT_EQUALS("[test.cpp:4]: (possible error) Dangerous usage of std::cin, possible buffer overrun\n", errout.str());
     }