Often the state of the preedit gets stuck. It seems to be timing related.
The most easy to reproduce case involves deletion.
1. Run gedit (also reproduced in pidgin and firefox).
2. Use scim-anthy.
3. Type "nihongo" but do not hit SPACE or ENTER. Typos are OK. Vary your typing timing.
4. Hit Delete to erase all of the pre-edit text.
5. Goto Step #3.
Eventually you will get to a state where the Delete button fails to delete some of the pre-edit buffer. If you enter a new character into pre-edit, then Delete is able to delete all characters.
==== FIREFOX VARIATION =====
There are variations of this where pre-edit behavior gets stuck in such a way that no typing, SPACE or ENTER responds anymore. CTRL-Space trigger to deactivate and activate it again is the only way to recover.
1. Go into a text box in firefox like this Bugzilla form.
2. Type "nihonn" quickly, hesitate a moment.
3. Type "go"
4. Quickly hit the Delete key a few times to attempt to erase the pre-edit buffer.
5. If you got the timing just right, it gets fully stuck needing the trigger to recover.
pidgin variation when I hit Delete on Step 4. No crash, but pre-edit is stuck and this prints to the console.
(pidgin:5501): IBUS-WARNING **: Traceback (most recent call last):
File "/usr/lib/python2.5/site-packages/dbus/service.py", line 702, in _message_cb
retval = candidate_method(self, *args, **keywords)
File "/usr/lib/python2.5/site-packages/ibus/engine.py", line 149, in ProcessKeyEvent
return self.__engine.process_key_event(keyval, is_press, state)
File "/usr/share/ibus-anthy/engine/engine.py", line 250, in process_key_event
File "/usr/share/ibus-anthy/engine/engine.py", line 553, in __on_key_back_space
File "/usr/share/ibus-anthy/engine/jastring.py", line 69, in remove_before
File "/usr/share/ibus-anthy/engine/romaji.py", line 138, in pop
raise IndexError("Out of bound")
IndexError: Out of bound
Fixed in ibus-anthy-0.1.1.20090203. Please test it.
You could download rpms from http://koji.fedoraproject.org/koji/buildinfo?buildID=81299
ibus-anthy-0.1.1.20090203-1.fc10 has been pushed to the Fedora 10 stable repository. If problems still persist, please make note of it in this bug report.