CppEditor: Return on invalid code in ExtractLiteralAsParameter::match

No declarator was provided but we assumed one.

Task-number: QTCREATORBUG-12853
Change-Id: I5faf96b63f39aff43c0165f7277345737e53f191
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/cppeditor/cppeditorplugin.h

@@ -201,13 +201,14 @@ private slots:
     void test_quickfix_ExtractLiteralAsParameter_typeDeduction();
     void test_quickfix_ExtractLiteralAsParameter_freeFunction_separateFiles();
     void test_quickfix_ExtractLiteralAsParameter_memberFunction_separateFiles();
+    void test_quickfix_ExtractLiteralAsParameter_notTriggeringForInvalidCode();
 
     void test_quickfix_InsertVirtualMethods_data();
     void test_quickfix_InsertVirtualMethods();
     void test_quickfix_InsertVirtualMethods_implementationFile();
     void test_quickfix_InsertVirtualMethods_BaseClassInNamespace();
 
-    // tests for "Include Hiererchy"
+    // tests for "Include Hierarchy"
     void test_includehierarchy_data();
     void test_includehierarchy();
 

src/plugins/cppeditor/cppquickfix_test.cpp

@@ -3614,3 +3614,21 @@ void CppEditorPlugin::test_quickfix_ExtractLiteralAsParameter_memberFunction_sep
     ExtractLiteralAsParameter factory;
     QuickFixTestCase(testFiles, &factory);
 }
+
+void CppEditorPlugin::test_quickfix_ExtractLiteralAsParameter_notTriggeringForInvalidCode()
+{
+    QList<QuickFixTestDocument::Ptr> testFiles;
+    QByteArray original;
+    QByteArray expected;
+
+    original =
+        "T(\"test\")\n"
+        "{\n"
+        "    const int i = @14;\n"
+        "}\n";
+    expected = original;
+    testFiles << QuickFixTestDocument::create("file.cpp", original, expected);
+
+    ExtractLiteralAsParameter factory;
+    QuickFixTestCase(testFiles, &factory);
+}

src/plugins/cppeditor/cppquickfixes.cpp

@@ -3884,13 +3884,15 @@ void ExtractLiteralAsParameter::match(const CppQuickFixInterface &interface,
             return;
     }
 
-    FunctionDeclaratorAST *functionDeclarator
-            = function->declarator->postfix_declarator_list->value->asFunctionDeclarator();
-    if (functionDeclarator
-            && functionDeclarator->parameter_declaration_clause
-            && functionDeclarator->parameter_declaration_clause->dot_dot_dot_token) {
-        // Do not handle functions with ellipsis parameter.
+    PostfixDeclaratorListAST * const declaratorList = function->declarator->postfix_declarator_list;
+    if (!declaratorList)
         return;
+    if (FunctionDeclaratorAST *declarator = declaratorList->value->asFunctionDeclarator()) {
+        if (declarator->parameter_declaration_clause
+                && declarator->parameter_declaration_clause->dot_dot_dot_token) {
+            // Do not handle functions with ellipsis parameter.
+            return;
+        }
     }
 
     const int priority = path.size() - 1;