1 files changed, 22 insertions, 17 deletions
diff --git a/Lib/idlelib/IOBinding.py b/Lib/idlelib/IOBinding.py
index 3f5d556..c4f14ef 100644
--- a/Lib/idlelib/IOBinding.py
+++ b/Lib/idlelib/IOBinding.py
@@ -1,5 +1,6 @@
 import os
 import types
+import pipes
 import sys
 import codecs
 import tempfile
@@ -156,29 +157,33 @@ class IOBinding:
                 self.filename_change_hook()
 
     def open(self, event=None, editFile=None):
-        if self.editwin.flist:
+        flist = self.editwin.flist
+        # Save in case parent window is closed (ie, during askopenfile()).
+        if flist:
             if not editFile:
                 filename = self.askopenfile()
             else:
                 filename=editFile
             if filename:
-                # If the current window has no filename and hasn't been
-                # modified, we replace its contents (no loss).  Otherwise
-                # we open a new window.  But we won't replace the
-                # shell window (which has an interp(reter) attribute), which
-                # gets set to "not modified" at every new prompt.
-                try:
-                    interp = self.editwin.interp
-                except AttributeError:
-                    interp = None
-                if not self.filename and self.get_saved() and not interp:
-                    self.editwin.flist.open(filename, self.loadfile)
+                # If editFile is valid and already open, flist.open will
+                # shift focus to its existing window.
+                # If the current window exists and is a fresh unnamed,
+                # unmodified editor window (not an interpreter shell),
+                # pass self.loadfile to flist.open so it will load the file
+                # in the current window (if the file is not already open)
+                # instead of a new window.
+                if (self.editwin and
+                        not getattr(self.editwin, 'interp', None) and
+                        not self.filename and
+                        self.get_saved()):
+                    flist.open(filename, self.loadfile)
                 else:
-                    self.editwin.flist.open(filename)
+                    flist.open(filename)
             else:
-                self.text.focus_set()
+                if self.text:
+                    self.text.focus_set()
             return "break"
-        #
+
         # Code for use outside IDLE:
         if self.get_saved():
             reply = self.maybesave()
@@ -232,7 +237,7 @@ class IOBinding:
             # before being able to execute the code
             self.set_saved(False)
         self.text.mark_set("insert", "1.0")
-        self.text.see("insert")
+        self.text.yview("insert")
         self.updaterecentfileslist(filename)
         return True
 
@@ -454,7 +459,7 @@ class IOBinding:
         else: #no printing for this platform
             printPlatform = False
         if printPlatform:  #we can try to print for this platform
-            command = command % filename
+            command = command % pipes.quote(filename)
             pipe = os.popen(command, "r")
             # things can get ugly on NT if there is no printer available.
             output = pipe.read().strip()