From e74d47ed03d6377b373623361eb22244660a3ea3 Mon Sep 17 00:00:00 2001
From: Fariborz Jahanian <fjahanian@apple.com>
Date: Thu, 12 Jan 2012 22:12:08 +0000
Subject: [PATCH] objc: do not warn when converting to a const id qualfied by
 its list of protools. // rdar://10669694

llvm-svn: 148051
---
 clang/lib/Sema/SemaExpr.cpp                   |  4 +++-
 .../ignore-qualifier-on-qualified-id.m        | 21 +++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 clang/test/SemaObjC/ignore-qualifier-on-qualified-id.m

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index ceb836b3e87c..8625d9b26012 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -5304,7 +5304,9 @@ checkObjCPointerTypesForAssignment(Sema &S, QualType LHSType,
   QualType lhptee = LHSType->getAs<ObjCObjectPointerType>()->getPointeeType();
   QualType rhptee = RHSType->getAs<ObjCObjectPointerType>()->getPointeeType();
 
-  if (!lhptee.isAtLeastAsQualifiedAs(rhptee))
+  if (!lhptee.isAtLeastAsQualifiedAs(rhptee) &&
+      // make an exception for id<P>
+      !LHSType->isObjCQualifiedIdType())
     return Sema::CompatiblePointerDiscardsQualifiers;
 
   if (S.Context.typesAreCompatible(LHSType, RHSType))
diff --git a/clang/test/SemaObjC/ignore-qualifier-on-qualified-id.m b/clang/test/SemaObjC/ignore-qualifier-on-qualified-id.m
new file mode 100644
index 000000000000..36a2c1ad873d
--- /dev/null
+++ b/clang/test/SemaObjC/ignore-qualifier-on-qualified-id.m
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -x objective-c++ -fsyntax-only -verify %s
+// rdar://10667659
+
+@protocol NSCopying @end
+
+@interface NSString <NSCopying>
+@end
+
+void takeId(id test) {}
+
+void takeCopyableId(id<NSCopying> test) {}
+
+id<NSCopying> Test () {
+  NSString const *constantString = @"Test";
+  takeId(constantString);
+  takeCopyableId(constantString);
+  id ID = constantString;
+  id<NSCopying> IDQNSCopying = constantString;
+  return constantString;
+}