Bug 617699 nsDOMFileReader::DispatchProgressEvent compares PRUint64 mReadTotal >= 0, r+a=sicking

content/base/src/nsDOMFileReader.cpp

@@ -88,6 +88,7 @@
 #define LOADEND_STR "loadend"
 
 #define NS_PROGRESS_EVENT_INTERVAL 50
+const PRUint64 kUnknownSize = PRUint64(-1);
 
 NS_IMPL_CYCLE_COLLECTION_CLASS(nsDOMFileReader)
 
@@ -519,7 +520,7 @@ nsDOMFileReader::ReadFileContent(nsIDOMBlob* aFile,
   }
 
   //Obtain the total size of the file before reading
-  mReadTotal = -1;
+  mReadTotal = kUnknownSize;
   mFile->GetSize(&mReadTotal);
 
   rv = mChannel->AsyncOpen(this, nsnull);
@@ -575,8 +576,17 @@ nsDOMFileReader::DispatchProgressEvent(const nsAString& aType)
   if (!progress)
     return;
 
-  progress->InitProgressEvent(aType, PR_FALSE, PR_FALSE, mReadTotal >= 0,
-                              mReadTransferred, PR_MAX(mReadTotal, 0));
+  PRBool known;
+  PRUint64 size;
+  if (mReadTotal != kUnknownSize) {
+    known = PR_TRUE;
+    size = mReadTotal;
+  } else {
+    known = PR_FALSE;
+    size = 0;
+  }
+  progress->InitProgressEvent(aType, PR_FALSE, PR_FALSE, known,
+                              mReadTransferred, size);
 
   this->DispatchDOMEvent(nsnull, event, nsnull, nsnull);
 }