null pointer: fixed false positive when condition checks if pointer is ok

lib/checkother.cpp

@@ -1129,6 +1129,22 @@ void CheckOther::nullPointerConditionalAssignment()
                 tok3 = tok3->next()->link();
                 if (!tok3)
                     break;
+
+                // check if the condition contains the variable..
+                for (const Token *tok4 = tok2->tokAt(2); tok4 && tok4 != tok3; tok4 = tok4->next())
+                {
+                    if (tok4->varId() == varid)
+                    {
+                        // The condition contains the variable..
+                        // to avoid false positives I bail out..
+                        tok3 = 0;
+                        break;
+                    }
+                }
+
+                if (!tok3)
+                    break;
+
                 if (tok3->next()->str() == "{")
                 {
                     tok2 = tok3->next()->link();

test/testother.cpp

@@ -910,6 +910,15 @@ private:
                          "    p->abcd();\n"
                          "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        checkNullPointer("static void foo()\n"
+                         "{\n"
+                         "    Foo *p = 0;\n"
+                         "    if (!p)\n"
+                         "        return;\n"
+                         "    p->abcd();\n"
+                         "}\n");
+        ASSERT_EQUALS("", errout.str());
     }