C++: fixed code completion for namespace aliases

Task-number: QTCREATORBUG-166

Change-Id: I7a19065a57bfb943e5fc4e2bd9bd81988c1175e3
Reviewed-by: Sergey Shambir <sergey.shambir.auto@gmail.com>
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/libs/cplusplus/LookupContext.cpp

@@ -641,7 +641,8 @@ void CreateBindings::lookupInScope(const Name *name, Scope *scope,
 
             if (s->asNamespaceAlias() && binding) {
                 ClassOrNamespace *targetNamespaceBinding = binding->lookupType(name);
-                if (targetNamespaceBinding && targetNamespaceBinding->symbols().size() == 1) {
+                //there can be many namespace definitions
+                if (targetNamespaceBinding && targetNamespaceBinding->symbols().size() > 0) {
                     Symbol *resolvedSymbol = targetNamespaceBinding->symbols().first();
                     item.setType(resolvedSymbol->type()); // override the type
                 }

src/plugins/cpptools/cppcompletion_test.cpp

@@ -1751,3 +1751,50 @@ void CppToolsPlugin::test_completion_typedef_using_templates2()
     QVERIFY(completions.contains(QLatin1String("Foo")));
     QVERIFY(completions.contains(QLatin1String("bar")));
 }
+
+void CppToolsPlugin::test_completion_namespace_alias_with_many_namespace_declarations()
+{
+    TestData data;
+    data.srcText =
+            "namespace NS1\n"
+            "{\n"
+            "namespace NS2\n"
+            "{\n"
+            "struct Foo1\n"
+            "{\n"
+            "    int bar1;\n"
+            "};\n"
+            "}\n"
+            "}\n"
+            "namespace NS1\n"
+            "{\n"
+            "namespace NS2\n"
+            "{\n"
+            "struct Foo2\n"
+            "{\n"
+            "    int bar2;\n"
+            "};\n"
+            "}\n"
+            "}\n"
+            "namespace NS = NS1::NS2;\n"
+            "int main()\n"
+            "{\n"
+            "    @\n"
+            "    // padding so we get the scope right\n"
+            "}\n"
+            ;
+    setup(&data);
+
+    Utils::ChangeSet change;
+    QString txt = QLatin1String("NS::");
+    change.insert(data.pos, txt);
+    QTextCursor cursor(data.doc);
+    change.apply(&cursor);
+    data.pos += txt.length();
+
+    QStringList completions = getCompletions(data);
+
+    QCOMPARE(completions.size(), 2);
+    QVERIFY(completions.contains(QLatin1String("Foo1")));
+    QVERIFY(completions.contains(QLatin1String("Foo2")));
+}

src/plugins/cpptools/cppcompletionassist.cpp

@@ -517,7 +517,9 @@ public:
 
     BasicProposalItem *operator()(Symbol *symbol)
     {
-        if (! symbol || ! symbol->name() || symbol->name()->isQualifiedNameId())
+        //using declaration can be qualified
+        if (! symbol || ! symbol->name() || (symbol->name()->isQualifiedNameId()
+                                             && ! symbol->asUsingDeclaration()))
             return 0;
 
         BasicProposalItem *previousItem = switchCompletionItem(0);

src/plugins/cpptools/cpptoolsplugin.h

@@ -126,6 +126,7 @@ private slots:
     void test_completion_template_specialization_with_pointer();
     void test_completion_typedef_using_templates1();
     void test_completion_typedef_using_templates2();
+    void test_completion_namespace_alias_with_many_namespace_declarations();
 
     void test_format_pointerdeclaration_in_simpledeclarations();
     void test_format_pointerdeclaration_in_simpledeclarations_data();