Soft undo does not work for the same text command called multiple times

[evandrocoan]

Description

1. Create this keybinding on your user settings

   [
       { "keys": ["alt+d"], "command": "select_highlighted_next_word" },
   ]

2. Create the plugin bug.py

   import sublime
   import sublime_plugin
   
   class SelectHighlightedNextWordCommand(sublime_plugin.TextCommand):
       def run(self, edit):
           view = self.view
           selections = view.sel()
   
           if selections:
               word_regions = view.find_all( 'selections' )
   
               if word_regions:
   
                   for next_word in word_regions:
   
                       if next_word in selections:
                           continue
   
                       selections.add(next_word)
                       view.show(next_word)
                       break

Expected behavior

1. Open a Sublime Text Vanilla Install
2. Create the file bug.py and its keybinding
3. Press Alt+D 3 times
4. Press Ctrl+U (soft_undo)
5. Only one selection is undone (unselected)

Actual behavior

1. Open a Sublime Text Vanilla Install
2. Create the file bug.py and its keybinding
3. Press Alt+D 3 times
4. Press Ctrl+U (soft_undo)
5. Now, all 3 selections were undone (it is expected for only one selection to be "undone")

Workaround

A fix or workaround for this problem was figured out accidentally by @OdatNurd and @mattst on https://forum.sublimetext.com/t/plugin-soft-undo/40064

If you create the bug.py by using two text commands chained by a sublime.set_timeout(), everything works as expected:

import sublime
import sublime_plugin

class SelectHighlightedNextWordCommand(sublime_plugin.TextCommand):
    def run(self, edit):
        view = self.view
        sublime.set_timeout( lambda: view.run_command( 'select_highlighted_next_word_bug_fixer' ), 0 )

class SelectHighlightedNextWordBugFixerCommand(sublime_plugin.TextCommand):
    def run(self, edit):
        view = self.view
        selections = view.sel()

        if selections:
            word_regions = view.find_all( 'selections' )

            if word_regions:

                for next_word in word_regions:

                    if next_word in selections:
                        continue

                    selections.add(next_word)
                    view.show(next_word)
                    break

Environment

• Operating system and version:
  • Windows 10 build 15063 x64
  • Resolution 1920x1080
  • dpi_scale 1.0
  • Sublime Text:
  • Build 3207
  • 64 bit

Related threads

1. https://forum.sublimetext.com/t/plugin-soft-undo/40064
2. https://github.com/SublimeTextIssues/Core/issues/2087 Commands "soft_undo" and "soft_redo" do not update visualization of dirty flag

[BenjaminSchaaf]

This is because Sublime Text joins together non-modifying commands that happen shortly after another. If you wait between each alt+d press then those will have separate entries in the undo stack.

There currently isn't a way for plugins to control this, so I'll take this issue to track adding such a feature.