Fixed false positives about uninitialized variables

lib/checkother.cpp

@@ -1286,6 +1286,8 @@ private:
     static void use(bool &foundError, std::list<ExecutionPath *> &checks, const Token *tok, const int mode)
     {
         const unsigned int varid(tok->varId());
+        if (varid == 0)
+            return;
 
         std::list<ExecutionPath *>::const_iterator it;
         for (it = checks.begin(); it != checks.end(); ++it)

test/testother.cpp

@@ -1315,6 +1315,13 @@ private:
                        "    strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));\n"
                        "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        checkUninitVar("void foo()\n"
+                       "{\n"
+                       "    const std::string s(x());\n"
+                       "    strchr(s.c_str(), ',');\n"
+                       "}\n");
+        ASSERT_EQUALS("", errout.str());
     }