On Thu, Aug 09, 2018 at 02:40:58PM -0700, Elijah Newren wrote: > > I worry that the false positives make this a non-starter. I mean, if > > clone creates files 'A' and 'B' (both equal) and then tries to create > > 'b', would the collision code reports that 'b' collided with 'A' because > > that was the first OID match? Ideally with this scheme we'd have to > > search the entire index prior to 'b' and then report that 'b' collided > > with either 'A' or 'B'. Neither message instills confidence. And > > there's no way to prefer answer 'B' over 'A' without using knowledge > > of the FS name mangling/aliasing rules -- unless we want to just assume > > ignore-case for this iteration. > > A possibly crazy idea: Don't bother reporting the other filename; just > report the OID instead. > > "Error: Foo.txt cannot be checked out because another file with hash > <whatever> is in the way." Maybe even add a hint for the user: "Run > `git ls-files -s` to see see all files and their hash". > > Whatever the exact wording for the error message, just create a nice > post on stackoverflow.com explaining the various weird filesystems out > there (VFAT, NTFS, HFS, APFS, etc) and how they cause differing > filenames to be written to the same location. Have a bunch of folks > vote it up so it has some nice search-engine juice.
Actually, I kind of like the simplicity of that. It puts the human brain in the loop. > The error message isn't quite as good, but does the user really need > all the names of the file? If so, we gave them enough information to > figure it out, and this is a really unusual case anyway, right? > Besides, now we're back to linear performance.... Well, it's still quadratic when they run O(n) iterations of "git ls-files -s | grep $colliding_oid". You've just pushed the second linear search onto the user. ;) -Peff
