ENH: more efficent fix for bug # 2063

Source/cmLocalVisualStudio7Generator.cxx

@@ -889,10 +889,12 @@ void cmLocalVisualStudio7Generator::OutputLibraries(std::ostream& fout,
           debugPostfix = m_Makefile->GetDefinition("CMAKE_DEBUG_POSTFIX");
           }
         }
-      // since windows is case insensitive then check for lower case .lib as
-      // at the end of the string, if not yet there add it.
-      std::string lowerCaseLib = cmSystemTools::LowerCase(j->first);
-      if(lowerCaseLib.rfind(".lib") != (lowerCaseLib.size()-4))
+      // chop off the last 4 chars of the library string
+      std::string lowerCaseLibExt = j->first.substr(j->first.size()-4, 4);
+      // lower case the extension
+      lowerCaseLibExt = cmSystemTools::LowerCase(lowerCaseLibExt);
+      // now check to see if it was a .lib, if not then add a .lib
+      if(lowerCaseLibExt != ".lib")
         {
         lib += debugPostfix + ".lib";
         }