Modifying EditorWindow causes breakpoints in that module to be removed
from both sides of the split debugger.
M Debugger.py
M EditorWindow.py
diff --git a/Lib/idlelib/EditorWindow.py b/Lib/idlelib/EditorWindow.py
index 453e6ca..a7aa185 100644
--- a/Lib/idlelib/EditorWindow.py
+++ b/Lib/idlelib/EditorWindow.py
@@ -101,6 +101,7 @@
             self.top.instanceDict=flist.inversedict
         self.recentFilesPath=os.path.join(idleConf.GetUserCfgDir(),
                 'recent-files.lst')
+        self.break_set = False
         self.vbar = vbar = Scrollbar(top, name='vbar')
         self.text_frame = text_frame = Frame(top)
         self.text = text = Text(text_frame, name='text', padx=5, wrap=None,
@@ -631,6 +632,9 @@
         if not self.get_saved():
             title = "*%s*" % title
             icon = "*%s" % icon
+            if self.break_set:
+                shell = self.flist.pyshell 
+                shell.interp.debugger.clear_file_breaks(self)
         self.top.wm_title(title)
         self.top.wm_iconname(icon)
 
@@ -699,8 +703,8 @@
         #print self.io.filename
         if self.io.filename:
             self.UpdateRecentFilesList(newFile=self.io.filename)
-        shell = self.flist.pyshell
-        if shell and shell.interp.debugger:
+        if self.break_set:
+            shell = self.flist.pyshell
             shell.interp.debugger.clear_file_breaks(self)
         WindowList.unregister_callback(self.postwindowsmenu)
         if self.close_hook: