Undoing phrase expansion fails, if triggered by a hotkey

[luziferius]

Classification:

Crash

Reproducibility:

Always

Summary

The KeypressHandler-thread crashes if a phrase expansion is triggered by a hotkey, and then is undone using the backspace key.

Steps to Reproduce

• Assign an abbreviation to trick the checking logic.
• Assign a hotkey to a phrase
• Press the hotkey to expand the phrase
• Press backspace to undo the expansion operation

Expected Results

• Pasted/typed phrase should disappear

Actual Results

2018-07-06 10:17:04,670 INFO - service - Undoing last abbreviation expansion
Exception in thread KeypressHandler-thread:
Traceback (most recent call last):
  File "/usr/lib/python3.6/threading.py", line 916, in _bootstrap_inner
    self.run()
  File "/home/thomas/Projekte/autokey/lib/autokey/iomediator/_iomediator.py", line 114, in run
    target.handle_keypress(rawKey, modifiers, key, windowName, windowClass)
  File "/home/thomas/Projekte/autokey/lib/autokey/service.py", line 180, in handle_keypress
    if self.__updateStack(key):
  File "/home/thomas/Projekte/autokey/lib/autokey/service.py", line 277, in __updateStack
    self.phraseRunner.undo_expansion()
  File "/home/thomas/Projekte/autokey/lib/autokey/service.py", line 416, in undo_expansion
    replay = self.lastPhrase.get_trigger_chars(self.lastBuffer)
  File "/home/thomas/Projekte/autokey/lib/autokey/model.py", line 822, in get_trigger_chars
    stringBefore, typedAbbr, stringAfter = self._partition_input(buffer, abbr)
  File "/home/thomas/Projekte/autokey/lib/autokey/model.py", line 249, in _partition_input
    stringBefore, typedAbbr, stringAfter = currentString.rpartition(abbr)
TypeError: must be str, not NoneType

Version

AutoKey version 0.95.1

Notes

It seems that "lastBuffer" contains the trigger abbreviation that was removed during expansion. This does not exist when using a hotkey, thus is not initialized.
Possible solutions:

• Initialize with an empty string (""), so that the logic does not break with TypeErrors
• Specifically handle this situation and skip the code, which is not needed in this case.

[luziferius]

Fixed in abf3345.
Phrase expansion can now always be un-done, even if triggered by a hotkey or menu.