I'm using Mercurial. I made a clone of a repository. For debugging, I changed a few lines of code in a java file. I did not commit those changes though. I just want to revert them back to their original state, as found in the repository. I tried hg revert filename.java, which did revert it, but now when I do hg status, I see additional files added in my folder now like:
? filename.java.orig
Can I just delete those files, and why does Mercurial make them when I use revert?
Yes, you can delete them. It's a safety feature in case you reverted something you didn't mean to revert.
As other's have pointed out, you can safely delete these files.
You can remove them by executing this command from the root of your repo:
rm `hg st -un | grep orig`
If you want to revert, and don't care at all about backing up the original files, the command you want is:
hg update -C
Those are copies of the files from before you reverted them. If you don't need those, you can delete them, either by hand or by using the Purge extension:
hg clean
These backup files can be created for merge and revert operations (cf. man page). You can add an ignore rule if you want, or simply delete them if you don't need them anymore.
These are rather common, resulting from various operations. A glance at one of the moderate sized repositories I work on finds 237 of them. I don't like deleting things that may end up being useful, and I have no reason to name legitimate files with the same suffix, so I add the following to .hgignore instead:
.\.orig$