When live preview is enabled ("whenever there are changes"), kile automatically saves the opened file in order to compile it. If you have configured the editor component to remove trailing space when saving, the saving is very annoying: Suppose you are typing and stop shortly to think about which word to type next. At that moment, kile saves the document and the space you have just typed is removed again. Reproducible: Always Steps to Reproduce: 1. Enable live preview (based on changes) and configure editor to remove trailing space before saving. 2. Type "word " and wait a moment. Actual Results: The space is removed. Expected Results: Actually, I don't know what a good behavior should look like... To only remove space when saving is triggered manually would turn the feature almost useless for users that have enabled live preview, because the automatic saving is usually faster than the user.
This is fixed in the latest KatePart (KDE 4.10 probably), see http://quickgit.kde.org/?p=kate.git&a=commit&h=cebe2e4c47655d4fdef27ad4a306b89dfbdf3302 and Bug 310712: https://bugs.kde.org/show_bug.cgi?id=310712
Today I realized that this problem reappeared: Kile consistently removes the space I've just (half a second ago) typed left to the cursor when saving the document due to live-previews. This is really annoying (for me) and I had to disable the removal of trailing whitespaces. I'm not sure if this is the right place for the bug-report, though. Certainly it's part of the behaviour of katepart, but it is also an unfortunate interaction of kate's whitespace-removal-feature and the automatic saving of kile due to live-preview. The comments in the bug report of katepart do not seem to discuss the case of automatic saving (only frequent pressing of Ctrl-S).