See this interaction of me with darcs:

reinier@adim:~/Sources/darcs-unstable$ darcs w thisdirdoesntexist/.
hunk ./tests/whatsnew-file.sh 55
-darcs wh foo foo/../foo/. > out
-cat out
-grep date out | wc -l | grep 1
+# This one fails actually, but it's not my fault. Filing a bug.
+#darcs wh foo foo/../foo/. > out
+#cat out
+#grep date out | wc -l | grep 1

I ask for changes in "thisdirdoesntexist/.", but instead it gives me all changes
in the repo. I traced the problem to the point that I found out that
Darcs.RepoPath.ioAbsolute returns "" when given "thisdirdoesntexist/." as input.
This "" is interpreted as "give me all changes" by subsequent functions.

Apparently fixed by Eric's work on removing dependencies on UglyFileName.