objc: 'id' and block pointer compare in mergeTypes is
made symmetrical. // rdar://10734265


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149065 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 5a7a73d..295489f 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -5934,9 +5934,12 @@
         return LHS;
     }
     // allow block pointer type to match an 'id' type.
-    if (OfBlockPointer && !BlockReturnType &&
-        LHS->isObjCIdType() && RHS->isBlockPointerType())
-      return LHS;
+    if (OfBlockPointer && !BlockReturnType) {
+       if (LHS->isObjCIdType() && RHS->isBlockPointerType())
+         return LHS;
+      if (RHS->isObjCIdType() && LHS->isBlockPointerType())
+        return RHS;
+    }
     
     return QualType();
   }
diff --git a/test/SemaObjC/block-id-as-block-argtype.m b/test/SemaObjC/block-id-as-block-argtype.m
index 1b71a5c..20bb6ad 100644
--- a/test/SemaObjC/block-id-as-block-argtype.m
+++ b/test/SemaObjC/block-id-as-block-argtype.m
@@ -9,13 +9,19 @@
 
 void fn(block4_t arg); // expected-note {{passing argument to parameter 'arg' here}}
 
+void another_fn(block2_t arg);
+
 int main() {
     block1_t b1;
     block2_t b2;
     block3_t b3;
     block3_t b4;
+    block4_t b5;
+
     fn(b1);  // expected-error {{incompatible block pointer types passing 'block1_t' (aka 'void (^)(int)') to parameter of type 'block4_t' (aka 'void (^)(id)')}}
     fn(b2);  // must succeed: block1_t *is* compatible with id
     fn(b3);  // succeeds: NSObject* compatible with id
     fn(b4);  // succeeds: id compatible with id
+
+    another_fn(b5);
 }