From ba42ceb0cb7827a9bbad29a1e08d4a25339ea57d Mon Sep 17 00:00:00 2001
From: Przemyslaw Gorszkowski <pgorszkowski@gmail.com>
Date: Wed, 30 Apr 2014 09:07:57 +0200
Subject: [PATCH] C++: nested class with enclosing template class

The parent of instantiation of nested class of template class
should be the instantiation of enclosing template class.

To prevent the infinite loop for case with local typedef of enclosing
template we should not change a parent of typedefed instatiation of
enclosing template. Example:
template <typename T>
struct Enclosing
{
  typedef Enclosing<T> EnclosingT;// first case
  struct Nested
  {
    typedef Enclosing<T> EnclosingT;// second case
  };
};

Task-number: QTCREATORBUG-11752
Task-number: QTCREATORBUG-11999
Change-Id: Iadd7b5ef73ee0c4881f59c9dabfe03339f55827b
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>
---
 src/libs/cplusplus/LookupContext.cpp        | 17 ++++++++++++++++
 src/plugins/cpptools/cppcompletion_test.cpp | 22 +++++++++++++++++++--
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/libs/cplusplus/LookupContext.cpp b/src/libs/cplusplus/LookupContext.cpp
index 98050c911b6..3828babe790 100644
--- a/src/libs/cplusplus/LookupContext.cpp
+++ b/src/libs/cplusplus/LookupContext.cpp
@@ -88,6 +88,19 @@ static void path_helper(Symbol *symbol, QList<const Name *> *names)
     }
 }
 
+static bool isNestedInstantiationEnclosingTemplate(
+        ClassOrNamespace *nestedClassOrNamespaceInstantiation,
+        ClassOrNamespace *enclosingTemplateClassInstantiation)
+{
+    while (enclosingTemplateClassInstantiation) {
+        if (enclosingTemplateClassInstantiation == nestedClassOrNamespaceInstantiation)
+            return false;
+        enclosingTemplateClassInstantiation = enclosingTemplateClassInstantiation->parent();
+    }
+
+    return true;
+}
+
 namespace CPlusPlus {
 
 static inline bool compareName(const Name *name, const Name *other)
@@ -1282,6 +1295,10 @@ void ClassOrNamespace::NestedClassInstantiator::instantiate(ClassOrNamespace *en
             }
         }
 
+        if (isNestedInstantiationEnclosingTemplate(nestedClassOrNamespaceInstantiation,
+                                                   enclosingTemplateClass)) {
+            nestedClassOrNamespaceInstantiation->_parent = enclosingTemplateClassInstantiation;
+        }
         instantiate(nestedClassOrNamespace, nestedClassOrNamespaceInstantiation);
 
         enclosingTemplateClassInstantiation->_classOrNamespaces[nestedName] =
diff --git a/src/plugins/cpptools/cppcompletion_test.cpp b/src/plugins/cpptools/cppcompletion_test.cpp
index e96c790c6c0..c1e03a84010 100644
--- a/src/plugins/cpptools/cppcompletion_test.cpp
+++ b/src/plugins/cpptools/cppcompletion_test.cpp
@@ -306,8 +306,6 @@ void CppToolsPlugin::test_completion()
     expectedCompletions.sort();
 
     QEXPECT_FAIL("enum_in_function_in_struct_in_function", "doesn't work", Abort);
-    QEXPECT_FAIL("nested_class_in_template_class_QTCREATORBUG-11752",
-                 "related to infiniteLoopLocalTypedef_QTCREATORBUG-11999", Abort);
     QCOMPARE(actualCompletions, expectedCompletions);
 }
 
@@ -2264,6 +2262,26 @@ void CppToolsPlugin::test_completion_data()
             << QLatin1String("foo")
             << QLatin1String("Foo"));
 
+    QTest::newRow("infiniteLoopLocalTypedef_QTCREATORBUG-11999") << _(
+            "template <typename T>\n"
+            "struct Temp\n"
+            "{\n"
+            "   struct Nested\n"
+            "   {\n"
+            "       typedef Temp<T> TempT;\n"
+            "       T t;\n"
+            "   };\n"
+            "   Nested nested;\n"
+            "};\n"
+            "struct Foo { int foo; };\n"
+            "void fun() {\n"
+            "   Temp<Foo> tempFoo;\n"
+            "   @\n"
+            "}\n"
+        ) << _("tempFoo.nested.t.") << (QStringList()
+            << QLatin1String("foo")
+            << QLatin1String("Foo"));
+
     QTest::newRow("lambda_parameter") << _(
             "auto func = [](int arg1) { return @; };\n"
         ) << _("ar") << (QStringList()