Bug 1431204 - Only addref the mutator if is not null r=mayhemer

MozReview-Commit-ID: 94VsIsLxx2T

--HG--
extra : rebase_source : 3608e624bd8dce13ac7a5dac45a3522b3b685460

caps/NullPrincipalURI.h

@@ -78,7 +78,10 @@ public:
 
     NS_IMETHOD SetSpec(const nsACString & aSpec, nsIURIMutator** aMutator) override
     {
-      NS_ADDREF(*aMutator = this);
+      if (aMutator) {
+        nsCOMPtr<nsIURIMutator> mutator = this;
+        mutator.forget(aMutator);
+      }
       return NS_ERROR_NOT_IMPLEMENTED;
     }
 

image/decoders/icon/nsIconURI.h

@@ -69,8 +69,12 @@ public:
       return NS_OK;
     }
 
-    NS_IMETHOD SetSpec(const nsACString & aSpec, nsIURIMutator** aMutator) override {
-      NS_ADDREF(*aMutator = this);
+    NS_IMETHOD SetSpec(const nsACString & aSpec, nsIURIMutator** aMutator) override
+    {
+      if (aMutator) {
+        nsCOMPtr<nsIURIMutator> mutator = this;
+        mutator.forget(aMutator);
+      }
       return InitFromSpec(aSpec);
     }