# Questions and Answers

## Chapter 5. Questions and Answers

This document may have been updated since your installation. You can find the latest version at http://docs.kde.org/current/kdeextragear-1/.

5.1. Why is it called "KDiff3"?
5.2. Why did I release it under GPL?
5.3. Some buttons and functions are missing. What's wrong?
5.4. Often lines that are similar but not identical appear next to each other but sometimes not. Why?
5.5. Why must all conflicts be solved before the merge result can be saved?
5.6. Why does the editor in the merge result window not have an "undo"-function?
5.7. When I removed some text, then suddenly "<No src line>" appeared and can't be deleted. What does that mean and how can one remove this?
5.8. Why doesn't KDiff3 support syntax-highlighting?
5.9. There is so much information here, but your question is still not answered?

5.1. | Why is it called "KDiff3"?
| Tools named "KDiff" and "KDiff2" (now called "Kompare") already exist. Also "KDiff3" should suggest that it can merge like the "diff3"-tool in the Diff-Tool collection.
5.2. | Why did I release it under GPL?
| I'm using GPL programs for a very long time now and learned very much by having a look at many of the sources. Hence this is my "Thank You" to all programmers that also did so or will do the same.
5.3. | Some buttons and functions are missing. What's wrong?
| You compiled from source but you probably didn't specify the correct KDE-prefix with configure. By default configure wants to install in /usr/local but then KDE can't find the user-interface ressource file (i.e. kdiff3ui.rc). The README-file contains more information about the correct prefix.
5.4. | Often lines that are similar but not identical appear next to each other but sometimes not. Why?
| Lines where only the amount of white space characters is different are treated as "equal" at first, while just one different non-white character causes the lines to be "different". If similar lines appear next to each other, this actually is coincidence but this fortunately is often the case.
5.5. | Why must all conflicts be solved before the merge result can be saved?
| For each equal or different section the editor in the merge result window remembers where it begins or ends. This is needed so that conflicts can be solved manually by simply selecting the source button (A, B or C). This information is lost while saving as text and it is too much effort to create a special file format that supports saving and restoring all necessary information.
5.6. | Why does the editor in the merge result window not have an "undo"-function?
| This was too much effort until now. You can always restore a version from one source (A, B or C) by clicking the respective button. For big editing the use of another editor is recommended anyway.
5.7. | When I removed some text, then suddenly "<No src line>" appeared and can't be deleted. What does that mean and how can one remove this?

For each equal or different section the editor in the merge result window remembers where it begins or ends. "<No src line>" means that there is nothing left in a section, not even a new line character. This can happen either while merging automatically or by editing. This is no problem, since this hint won't appear in the saved file. If you want the orignal source back just select the section (click on the left summary column) and then click the source button with the needed contents (A/B or C).

5.8. | Why doesn't KDiff3 support syntax-highlighting?
| KDiff3 already uses many colors for difference highlighting. More highlighting would be confusing. Use another editor for this.
5.9. | There is so much information here, but your question is still not answered?
| Please send me your question. I appreciate every comment.