Only a read of 0 means EOF. r=dougt

xpcom/io/nsFileStream.cpp

@@ -61,7 +61,7 @@ PRInt32 nsInputStream::read(void* s, PRInt32 n)
       return 0;
   PRInt32 result = 0;
   mInputStream->Read((char*)s, n, (PRUint32*)&result);
-  if (result < n)
+  if (result == 0)
       set_at_eof(PR_TRUE);
   return result;
 } // nsInputStream::read