M Debugger.py
M IOBinding.py
M PyShell.py

* Could not remove last set of saved breakpoints from a file
* Starting with empty edit window, could not load a file
* Multiple adjacent breakpoints were saved as one breakpoint
* Storing breakpoints whenever a file is closed can get them out
  of synch with the saved version of a file.  Only store them when the
  file is saved.
* Add comment on current limitations on file editing in the presence of
  breakpoints.
* Replace get_current_breaks() with update_breakpoints(), add an update to
  PyShellEditorWindow.breakpoints, which is the master breakpoint data
  structure, and which is used to reload the subprocess debugger.
* Revert Debugger.Debugger.load_breakpoints() to use editwin.breakpoints.
  It is easier to debug the debugger if the breakpoint list in IDLE is
  identical to the list in the subprocess debugger and is transferred when
  the subprocess debugger is restarted, because this list can be easily
  queried.
* Cleanup some linespacing and comments in IOBinding.py
diff --git a/Lib/idlelib/PyShell.py b/Lib/idlelib/PyShell.py
index cf93613..f6e85f7 100644
--- a/Lib/idlelib/PyShell.py
+++ b/Lib/idlelib/PyShell.py
@@ -67,10 +67,6 @@
 class PyShellEditorWindow(EditorWindow):
     "Regular text edit window when a shell is present"
 
-    # XXX KBK 10Dec02 Breakpoints are currently removed if module is modified.
-    # In the future, it may be possible to preserve breakpoints by changing
-    # their line numbers as a module is modified.
-
     def __init__(self, *args):
         self.breakpoints = []
         apply(EditorWindow.__init__, (self,) + args)
@@ -78,11 +74,12 @@
         self.text.bind("<<clear-breakpoint-here>>", self.clear_breakpoint_here)
         self.text.bind("<<open-python-shell>>", self.flist.open_shell)
 
-        self.breakpointPath=os.path.join(idleConf.GetUserCfgDir(), 'breakpoints.lst')
-
+        self.breakpointPath = os.path.join(idleConf.GetUserCfgDir(),
+                                           'breakpoints.lst')
         # whenever a file is changed, restore breakpoints
         if self.io.filename: self.restore_file_breaks()
-        def filename_changed_hook(old_hook=self.io.filename_change_hook,self=self):
+        def filename_changed_hook(old_hook=self.io.filename_change_hook,
+                                  self=self):
             self.restore_file_breaks()
             old_hook()
         self.io.set_filename_change_hook(filename_changed_hook)
@@ -148,49 +145,82 @@
                 pass
 
     def store_file_breaks(self):
-        if not self.breakpoints:
-            return
-        filename=self.io.filename
+        "Save breakpoints when file is saved"
+        # XXX 13 Dec 2002 KBK Currently the file must be saved before it can
+        #     be run.  The breaks are saved at that time.  If we introduce
+        #     a temporary file save feature the save breaks functionality
+        #     needs to be re-verified, since the breaks at the time the
+        #     temp file is created may differ from the breaks at the last
+        #     permanent save of the file.  A break introduced after a save
+        #     will be effective,  but not persistent.  This is necessary to
+        #     keep the saved breaks synched with the saved file.
+        #
+        #     Breakpoints are set as tagged ranges in the text.  Certain
+        #     kinds of edits cause these ranges to be deleted: Inserting
+        #     or deleting a line just before a breakpoint, and certain
+        #     deletions prior to a breakpoint.  These issues need to be
+        #     investigated and understood.  It's not clear if they are
+        #     Tk issues or IDLE issues, or whether they can actually
+        #     be fixed.  Since a modified file has to be saved before it is
+        #     run, and since self.breakpoints (from which the subprocess
+        #     debugger is loaded) is updated during the save, the visible
+        #     breaks stay synched with the subprocess even if one of these
+        #     unexpected breakpoint deletions occurs.
+        breaks = self.breakpoints
+        filename = self.io.filename
         try:
-            lines=open(self.breakpointPath,"r").readlines()
+            lines = open(self.breakpointPath,"r").readlines()
         except IOError:
-            lines=[]
-        new_file=open(self.breakpointPath,"w")
+            lines = []
+        new_file = open(self.breakpointPath,"w")
         for line in lines:
-            if not line.startswith(filename+"="):
+            if not line.startswith(filename + '='):
                 new_file.write(line)
-        new_file.write(filename+"="+`self.get_current_breaks()`+"\n")
+        self.update_breakpoints()
+        breaks = self.breakpoints
+        if breaks:
+            new_file.write(filename + '=' + str(breaks) + '\n')
         new_file.close()
 
     def restore_file_breaks(self):
         self.text.update()   # this enables setting "BREAK" tags to be visible
-        filename=self.io.filename
+        filename = self.io.filename
+        if filename is None:
+            return
         if os.path.isfile(self.breakpointPath):
-            lines=open(self.breakpointPath,"r").readlines()
+            lines = open(self.breakpointPath,"r").readlines()
             for line in lines:
-                if line.startswith(filename+"="):
-                    breakpoint_linenumbers=eval(line[len(filename)+1:]) 
+                if line.startswith(filename + '='):
+                    breakpoint_linenumbers = eval(line[len(filename)+1:]) 
                     for breakpoint_linenumber in breakpoint_linenumbers:
                         self.set_breakpoint(breakpoint_linenumber)
 
-    def get_current_breaks(self):
-        #
-        # retrieves all the breakpoints in the current window
-        #
+    def update_breakpoints(self):
+        "Retrieves all the breakpoints in the current window"
         text = self.text
-        lines = text.tag_ranges("BREAK")
-        result = [int(float((lines[i]))) for i in range(0,len(lines),2)]
-        return result
- 
-    def saved_change_hook(self):
-        "Extend base method - clear breaks if module is modified"
-        if not self.get_saved():
-            self.clear_file_breaks()
-        EditorWindow.saved_change_hook(self)
+        ranges = text.tag_ranges("BREAK")
+        linenumber_list = self.ranges_to_linenumbers(ranges)
+        self.breakpoints = linenumber_list
+
+    def ranges_to_linenumbers(self, ranges):
+        lines = []
+        for index in range(0, len(ranges), 2):
+            lineno = int(float(ranges[index]))
+            end = int(float(ranges[index+1]))
+            while lineno < end:
+                lines.append(lineno)
+                lineno += 1
+        return lines
+
+# XXX 13 Dec 2020 KBK Not used currently
+#    def saved_change_hook(self):
+#        "Extend base method - clear breaks if module is modified"
+#        if not self.get_saved():
+#            self.clear_file_breaks()
+#        EditorWindow.saved_change_hook(self)
 
     def _close(self):
         "Extend base method - clear breaks when module is closed"
-        self.store_file_breaks()
         self.clear_file_breaks()
         EditorWindow._close(self)