Nathan Hartman wrote on Mon, 07 Dec 2020 20:50 +00:00: > On Mon, Dec 7, 2020 at 1:47 PM Yasuhito FUTATSUKI > <futat...@yf.bsdclub.org> wrote: > > > > As the error message says, '-c' option accepts only numeric revision. > > It seems it is a kind of bug that the help text is not kind enough. > > A possible rationale is that the HEAD revision could change without > your knowledge (e.g., another user commits something in the meantime) > and you wouldn't get the revision you were expecting.
If this were the rationale, we wouldn't support «svn log -r HEAD» either. Use of «HEAD» to refer to any specific revision is inherently racy. Callsites that care about the race condition should handle it explicitly; see tools/dist/release.py:bump_versions_on_branch() for an example. There isn't any conceptual problem with defining «-c HEAD» to mean "Resolve HEAD to a revision number N and then behave as «-r N-1:N» would". That wouldn't be any more racy than any other use of HEAD. We just never did that. (Why? For one, because -c is a lot newer than -r: -c was added in 1.4.0 (sic), in 2006, while -r dates back to CVS. When we added -c, it was implemented directly in the cmdline client's option parser, without any API changes, so it was written to only support numeric arguments.) Note that «svn diff -c HEAD» isn't generally a useful call unless the repository root («^/») is given as the target. > When I want to see the diff of the most recent revision I use 'svn log > -l 1 --diff'. (Note, though, that will be from the BASE revision, not > HEAD.) There's also «svn log -r HEAD:0 -l 1 --diff». Cheers, Daniel
