--- a/dom/base/DOMException.cpp
+++ b/dom/base/DOMException.cpp
@@ -345,26 +345,38 @@ Exception::GetName(char** aName)
   return NS_OK;
 }
 
 /* readonly attribute string filename; */
 NS_IMETHODIMP
 Exception::GetFilename(char** aFilename)
 {
   NS_ENSURE_TRUE(mInitialized, NS_ERROR_NOT_INITIALIZED);
-    XPC_STRING_GETTER_BODY(aFilename, mFilename);
+
+  if (mLocation) {
+    return mLocation->GetFilename(aFilename);
+  }
+
+  XPC_STRING_GETTER_BODY(aFilename, mFilename);
 }
 
 /* readonly attribute uint32_t lineNumber; */
 NS_IMETHODIMP
 Exception::GetLineNumber(uint32_t *aLineNumber)
 {
   NS_ENSURE_ARG_POINTER(aLineNumber);
   NS_ENSURE_TRUE(mInitialized, NS_ERROR_NOT_INITIALIZED);
 
+  if (mLocation) {
+    int32_t lineno;
+    nsresult rv = mLocation->GetLineNumber(&lineno);
+    *aLineNumber = lineno;
+    return rv;
+  }
+
   *aLineNumber = mLineNumber;
   return NS_OK;
 }
 
 /* readonly attribute uint32_t columnNumber; */
 NS_IMETHODIMP
 Exception::GetColumnNumber(uint32_t* aColumnNumber)
 {
@@ -474,25 +486,16 @@ Exception::Initialize(const char *aMessa
   if (aName) {
     mName = (char*) nsMemory::Clone(aName, sizeof(char)*(strlen(aName)+1));
   }
 
   mResult = aResult;
 
   if (aLocation) {
     mLocation = aLocation;
-    // For now, fill in our location details from our stack frame.
-    // Later we may allow other locations?
-    nsresult rc;
-    if (NS_FAILED(rc = aLocation->GetFilename(&mFilename))) {
-      return rc;
-    }
-    if (NS_FAILED(rc = aLocation->GetLineNumber(&mLineNumber))) {
-      return rc;
-    }
   } else {
     nsresult rv;
     nsXPConnect* xpc = nsXPConnect::XPConnect();
     rv = xpc->GetCurrentJSStack(getter_AddRefs(mLocation));
     if (NS_FAILED(rv)) {
       return rv;
     }
   }
@@ -553,16 +556,24 @@ Exception::GetFilename(nsString& retval)
   MOZ_ASSERT(NS_SUCCEEDED(rv));
   CopyUTF8toUTF16(str, retval);
   nsMemory::Free(str);
 }
 
 uint32_t
 Exception::LineNumber() const
 {
+  if (mLocation) {
+    int32_t lineno;
+    if (NS_SUCCEEDED(mLocation->GetLineNumber(&lineno))) {
+      return lineno;
+    }
+    return 0;
+  }
+
   return mLineNumber;
 }
 
 uint32_t
 Exception::ColumnNumber() const
 {
   return 0;
 }