diff --git a/clang/lib/Checker/CocoaConventions.cpp b/clang/lib/Checker/CocoaConventions.cpp
index b446a048d4888945db80b30cd070f21e204bb657..8a3abc8bae7e6e61ece3e6fb33c56307cf4fa3eb 100644
--- a/clang/lib/Checker/CocoaConventions.cpp
+++ b/clang/lib/Checker/CocoaConventions.cpp
@@ -63,72 +63,48 @@ cocoa::NamingConvention cocoa::deriveNamingConvention(Selector S) {
 
   // A method/function name may contain a prefix.  We don't know it is there,
   // however, until we encounter the first '_'.
-  bool InPossiblePrefix = true;
-  bool AtBeginning = true;
-  NamingConvention C = NoConvention;
-
   while (*s != '\0') {
-    // Skip '_'.
-    if (*s == '_') {
-      if (InPossiblePrefix) {
-        // If we already have a convention, return it.  Otherwise, skip
-        // the prefix as if it wasn't there.
-        if (C != NoConvention)
-          break;
-        
-        InPossiblePrefix = false;
-        AtBeginning = true;
-        assert(C == NoConvention);
-      }
-      ++s;
-      continue;
-    }
-
-    // Skip numbers, ':', etc.
-    if (!isalpha(*s)) {
+    // Skip '_', numbers, ':', etc.
+    if (*s == '_' || !isalpha(*s)) {      
       ++s;
       continue;
     }
+    break;
+  }
 
-    const char *wordEnd = parseWord(s);
-    assert(wordEnd > s);
-    unsigned len = wordEnd - s;
+  // Parse the first word, and look for specific keywords.
+  const char *wordEnd = parseWord(s);
+  assert(wordEnd > s);
+  unsigned len = wordEnd - s;
 
-    switch (len) {
+  switch (len) {
     default:
-      break;
+      return NoConvention;
     case 3:
       // Methods starting with 'new' follow the create rule.
-      if (AtBeginning && StringRef(s, len).equals_lower("new"))
-        C = CreateRule;
-      break;
+      return (memcmp(s, "new", 3) == 0) ? CreateRule : NoConvention;
     case 4:
-      // Methods starting with 'alloc' or contain 'copy' follow the
-      // create rule
-      if (C == NoConvention && StringRef(s, len).equals_lower("copy"))
-        C = CreateRule;
-      else // Methods starting with 'init' follow the init rule.
-        if (AtBeginning && StringRef(s, len).equals_lower("init"))
-          C = InitRule;
-      break;
+      // Methods starting with 'copy' follow the create rule.
+      if (memcmp(s, "copy", 4) == 0)
+        return CreateRule;
+      // Methods starting with 'init' follow the init rule.
+      if (memcmp(s, "init", 4) == 0)
+        return InitRule;
+      return NoConvention;
     case 5:
-      if (AtBeginning && StringRef(s, len).equals_lower("alloc"))
-        C = CreateRule;
-      break;
-    }
-
-    // If we aren't in the prefix and have a derived convention then just
-    // return it now.
-    if (!InPossiblePrefix && C != NoConvention)
-      return C;
-
-    AtBeginning = false;
-    s = wordEnd;
+      return (memcmp(s, "alloc", 5) == 0) ? CreateRule : NoConvention;
+    case 7:
+      // Methods starting with 'mutableCopy' follow the create rule.
+      if (memcmp(s, "mutable", 7) == 0) {
+        // Look at the next word to see if it is "Copy".
+        s = wordEnd;
+        wordEnd = parseWord(s);
+        len = wordEnd - s;
+        if (len == 4 && memcmp(s, "Copy", 4) == 0)
+          return CreateRule;
+      }
+      return NoConvention;
   }
-
-  // We will get here if there wasn't more than one word
-  // after the prefix.
-  return C;
 }
 
 bool cocoa::isRefType(QualType RetTy, llvm::StringRef Prefix,
diff --git a/clang/test/Analysis/refcnt_naming.m b/clang/test/Analysis/refcnt_naming.m
index 9defce2735ef0f53101e6d56d72d25aeb5f04fd2..f84dd6e054365f381a189beb8cb352a72de0b151 100644
--- a/clang/test/Analysis/refcnt_naming.m
+++ b/clang/test/Analysis/refcnt_naming.m
@@ -11,6 +11,8 @@ typedef signed char BOOL;
 @class NSArray, NSString, NSURL;
 
 @interface NamingTest : NSObject {}
+-(NSObject*)copyPhoto;
+-(NSObject*)mutableCopyPhoto;
 -(NSObject*)photocopy;    // read as "photocopy"
 -(NSObject*)photoCopy;    // read as "photo Copy"
 -(NSObject*)__blebPRCopy; // read as "bleb PRCopy"
@@ -45,9 +47,11 @@ typedef signed char BOOL;
 }
 
 void testNames(NamingTest* x) {
+  [x copyPhoto]; // expected-warning{{leak}}
+  [x mutableCopyPhoto]; // expected-warning{{leak}}
   [x photocopy]; // no-warning
-  [x photoCopy]; // expected-warning{{leak}}
-  [x __blebPRCopy]; // expected-warning{{leak}}
+  [x photoCopy]; // no-warning
+  [x __blebPRCopy]; // no-warning
   [x __blebPRcopy]; // no-warning
   [x new_theprefixdoescount]; // expected-warning{{leak}}
   [x newestAwesomeStuff]; // no-warning
diff --git a/clang/test/Analysis/retain-release.m b/clang/test/Analysis/retain-release.m
index edaedcb4f5066def617c2e78e24bc8bce0db74e3..f6e43c99e88bde9b5de7b9e6d27a1fa244d5bf15 100644
--- a/clang/test/Analysis/retain-release.m
+++ b/clang/test/Analysis/retain-release.m
@@ -762,13 +762,13 @@ int RDar6320065_test() {
 @end
 
 @implementation RDar6859457 
-- (NSString*) NoCopyString { return [[NSString alloc] init]; } // no-warning
-- (NSString*) noCopyString { return [[NSString alloc] init]; } // no-warning
+- (NSString*) NoCopyString { return [[NSString alloc] init]; } // expected-warning{{leak}}
+- (NSString*) noCopyString { return [[NSString alloc] init]; } // expected-warning{{leak}}
 @end
 
 void test_RDar6859457(RDar6859457 *x, void *bytes, NSUInteger dataLength) {
-  [x NoCopyString]; // expected-warning{{leak}}
-  [x noCopyString]; // expected-warning{{leak}}
+  [x NoCopyString]; // no-warning
+  [x noCopyString]; // no-warning
   [NSData dataWithBytesNoCopy:bytes length:dataLength];  // no-warning
   [NSData dataWithBytesNoCopy:bytes length:dataLength freeWhenDone:1]; // no-warning
 }