Issue #12590: IDLE editor window now always displays the first line
when opening a long file.  With Tk 8.5, the first line was hidden.
diff --git a/Lib/idlelib/IOBinding.py b/Lib/idlelib/IOBinding.py
index a8c351f..c515432 100644
--- a/Lib/idlelib/IOBinding.py
+++ b/Lib/idlelib/IOBinding.py
@@ -266,7 +266,7 @@
         self.reset_undo()
         self.set_filename(filename)
         self.text.mark_set("insert", "1.0")
-        self.text.see("insert")
+        self.text.yview("insert")
         self.updaterecentfileslist(filename)
         return True