You're receiving this bug because the package in Summary has produced _FORTIFY_SOURCE related warnings indicating the presence of a sure overflow in a static buffer.
Even though this is not always an indication of a security problem it might even be. So please check this out ASAP.
By the way, _FORTIFY_SOURCE is disabled when you disable optimisation, so don't try finding out the cause using -O0.
Your friendly neighborhood tinderboxer
Created attachment 250507 [details]
Created attachment 261032 [details, diff]
buffer overflow fix
Created attachment 261034 [details]
New ebuild to apply buffer overflow patch
Don't know how the original author let this one slip by. When reading the .davrc file he defines a buffer of 80 bytes, then tries to fgets 200 bytes into it. Everything works OK so long as there aren't any lines in the file > 80 bytes long, but it overflows the buffer if there are.
While not the most robust fix, I've just changed the buffer size to 200 so fgets can't overflow it. Unfortunately, this means that the maximum length of a line in .davrc is 200 bytes. But, anything longer will just be truncated to 200 bytes instead of causing a buffer overflow now.
Patch added to portage as app-editors/dav-0.8.5-r1.