diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 046b18712c38..409219a57156 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -413,7 +413,16 @@ comments::FullComment *ASTContext::getCommentForDecl(
   if (!RC) {
     if (isa<ObjCMethodDecl>(D) || isa<FunctionDecl>(D)) {
       SmallVector<const NamedDecl*, 8> Overridden;
-      if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D))
+      const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D);
+      if (OMD && OMD->isPropertyAccessor()) {
+        if (const ObjCPropertyDecl *PDecl = OMD->findPropertyDecl()) {
+          if (comments::FullComment *FC = getCommentForDecl(PDecl, PP)) {
+            comments::FullComment *CFC = cloneFullComment(FC, D);
+            return CFC;
+          }
+        }
+      }
+      if (OMD)
         addRedeclaredMethods(OMD, Overridden);
       getOverriddenMethods(dyn_cast<NamedDecl>(D), Overridden);
       for (unsigned i = 0, e = Overridden.size(); i < e; i++) {
diff --git a/clang/lib/AST/DeclObjC.cpp b/clang/lib/AST/DeclObjC.cpp
index 32503ad78578..816c43200a89 100644
--- a/clang/lib/AST/DeclObjC.cpp
+++ b/clang/lib/AST/DeclObjC.cpp
@@ -947,6 +947,11 @@ ObjCMethodDecl::findPropertyDecl(bool CheckOverrides) const {
   
   if (isPropertyAccessor()) {
     const ObjCContainerDecl *Container = cast<ObjCContainerDecl>(getParent());
+    // If container is class extension, find its primary class.
+    if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(Container))
+      if (CatDecl->IsClassExtension())
+        Container = CatDecl->getClassInterface();
+    
     bool IsGetter = (NumArgs == 0);
 
     for (ObjCContainerDecl::prop_iterator I = Container->prop_begin(),
diff --git a/clang/test/Index/annotate-comments-property-accessor.m b/clang/test/Index/annotate-comments-property-accessor.m
new file mode 100644
index 000000000000..2bd1d0135cdd
--- /dev/null
+++ b/clang/test/Index/annotate-comments-property-accessor.m
@@ -0,0 +1,62 @@
+// RUN: rm -rf %t
+// RUN: mkdir %t
+// RUN: c-index-test -test-load-source all -comments-xml-schema=%S/../../bindings/xml/comment-xml-schema.rng %s > %t/out
+// RUN: FileCheck %s < %t/out
+// rdar://12378879
+
+// Ensure that XML we generate is not invalid.
+// RUN: FileCheck %s -check-prefix=WRONG < %t/out
+// WRONG-NOT: CommentXMLInvalid
+
+@interface AppDelegate
+/**
+  \brief This is ReadonlyProperty
+*/
+@property (readonly, getter = ReadonlyGetter) int MyProperty;
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}annotate-comments-property-accessor.m" line="[[@LINE-1]]" column="51"><Name>MyProperty</Name><USR>c:objc(cs)AppDelegate(py)MyProperty</USR><Declaration>- (int)ReadonlyGetter;</Declaration><Abstract><Para> This is ReadonlyProperty</Para></Abstract></Function>]
+
+/**
+  \brief This is GeneralProperty
+*/
+@property int GeneralProperty;
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}annotate-comments-property-accessor.m" line="[[@LINE-1]]" column="15"><Name>GeneralProperty</Name><USR>c:objc(cs)AppDelegate(py)GeneralProperty</USR><Declaration>- (int)GeneralProperty;</Declaration><Abstract><Para> This is GeneralProperty</Para></Abstract></Function>]
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}annotate-comments-property-accessor.m" line="[[@LINE-2]]" column="15"><Name>GeneralProperty</Name><USR>c:objc(cs)AppDelegate(py)GeneralProperty</USR><Declaration>- (void)setGeneralProperty:(int)GeneralProperty;</Declaration><Abstract><Para> This is GeneralProperty</Para></Abstract></Function>]
+
+/**
+  \brief This is PropertyInPrimaryClass
+*/
+@property (copy, nonatomic) id PropertyInPrimaryClass;
+- (void) setThisRecord : (id)arg;
+- (id) Record;
+@end
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}annotate-comments-property-accessor.m" line="[[@LINE-4]]" column="32"><Name>PropertyInPrimaryClass</Name><USR>c:objc(cs)AppDelegate(py)PropertyInPrimaryClass</USR><Declaration>- (id)PropertyInPrimaryClass;</Declaration><Abstract><Para> This is PropertyInPrimaryClass</Para></Abstract></Function>]
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}annotate-comments-property-accessor.m" line="[[@LINE-5]]" column="32"><Name>PropertyInPrimaryClass</Name><USR>c:objc(cs)AppDelegate(py)PropertyInPrimaryClass</USR><Declaration>- (void)setPropertyInPrimaryClass:(id)PropertyInPrimaryClass;</Declaration><Abstract><Para> This is PropertyInPrimaryClass</Para></Abstract></Function>]
+
+@interface AppDelegate()
+- (id) GetterInClassExtension;
+/**
+  \brief This is Record
+*/
+@property (copy, setter = setThisRecord:) id Record;
+@end
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}annotate-comments-property-accessor.m" line="[[@LINE-6]]" column="1"><Name>PropertyInClassExtension</Name><USR>c:objc(cs)AppDelegate(py)PropertyInClassExtension</USR><Declaration>- (id)GetterInClassExtension;</Declaration><Abstract><Para> This is PropertyInClassExtension</Para></Abstract></Function>]
+
+@interface AppDelegate()
+/**
+  \brief This is PropertyInClassExtension
+*/
+@property (copy, getter = GetterInClassExtension) id PropertyInClassExtension;
+
+- (id) PropertyInPrimaryClass;
+@end
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}annotate-comments-property-accessor.m" line="[[@LINE-4]]" column="54"><Name>PropertyInClassExtension</Name><USR>c:objc(cs)AppDelegate(py)PropertyInClassExtension</USR><Declaration>- (id)GetterInClassExtension;</Declaration><Abstract><Para> This is PropertyInClassExtension</Para></Abstract></Function>]
+// CHECK: FullCommentAsXML=[<Function isInstanceMethod="1" file="{{[^"]+}}annotate-comments-property-accessor.m" line="[[@LINE-5]]" column="54"><Name>PropertyInClassExtension</Name><USR>c:objc(cs)AppDelegate(py)PropertyInClassExtension</USR><Declaration>- (void)setPropertyInClassExtension:(id)PropertyInClassExtension;</Declaration><Abstract><Para> This is PropertyInClassExtension</Para></Abstract></Function>]
+  
+@implementation AppDelegate
+- (id) PropertyInPrimaryClass { return 0; }
+@end
+
+
+
+
+