The problem happens only when the program typed into supports surrounding text. For example, when typing into gedit (or any other gnome program), this problem occurs. In gedit (and most other programs), the Left, Right, Backspace, and Delete keys have special functions when used together with modifier keys. For example, Control+Left moves the cursor one word to left. Control+Backspace removes a whole word to the left of the cursor. Shift+Left marks a region in gedit (gets a blue background) and that region can then be removed with Delete or Backspace. Alt+Backspace exchanges the two words left of the cursor. Etc. ... So in all these cases, reopening the preëdit does not work the same way as when Left, Right, Backspace, or Delete are used to without the modifiers. As the behaviour of these key combinations is not exactly the same in all programs, it is not possible to reopen the preëdit correctly in all programs. Therefore, better don’t try to reopen the preëdit at all when Left, Right, Backspace, or Delete are used with any modifier (except CapsLock which does cause no such problems).
Created attachment 1242380 [details] example-that-preedit-is-reopened-incorrectly-when-using-control-arrow-left.ogv Video showing what happens when the preëdit is reopened using Control+ArrowLeft.
ibus-typing-booster-1.5.19-1.fc24 has been submitted as an update to Fedora 24. https://bodhi.fedoraproject.org/updates/FEDORA-2017-dbf2db3cfa
ibus-typing-booster-1.5.19-2.fc24 has been submitted as an update to Fedora 24. https://bodhi.fedoraproject.org/updates/FEDORA-2017-803b903185
ibus-typing-booster-1.5.19-2.fc25 has been submitted as an update to Fedora 25. https://bodhi.fedoraproject.org/updates/FEDORA-2017-524653c0dd
ibus-typing-booster-1.5.19-2.fc24 has been pushed to the Fedora 24 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2017-803b903185
ibus-typing-booster-1.5.19-2.fc25 has been pushed to the Fedora 25 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2017-524653c0dd
ibus-typing-booster-1.5.19-2.fc25 has been pushed to the Fedora 25 stable repository. If problems still persist, please make note of it in this bug report.
ibus-typing-booster-1.5.19-2.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.