On Wed, Feb 6, 2013 at 12:07 AM, Stefan Sperling <s...@apache.org> wrote: > On Tue, Feb 05, 2013 at 09:18:33PM +0100, Johan Corveleyn wrote: >> Hmm, okay, but I would have preferred some more discussion before you >> implemented this. It's not clear to me that this decreases the >> surprises. I can perfectly imagine just as many questions being asked >> on users@ with the question: "Why does 'svn diff left.txt right.txt' >> give me an empty diff, while 'svn diff ^/left.txt right.txt' does the >> right thing?" >> >> I think it would be better to consistently point users to the >> --old/--new syntax, so as to educate users more (so I'm okay with the >> change in the error message), not hide it even more from them. > > Well, the point that convinced me was that previously 'svn diff' raised > an error in the case of 'svn diff ^/left.txt right.txt'. > That's clearly intended to be a comparison between a URL and a path, > which the diff code already supports. So I think the diff code should > just show an appropriate diff. I don't see how people could be conflating > a URL->WC or WC->URL diff with a WC->WC diff. > > BTW, I'm thinking about adding more shortcuts: > > svn diff UNVERSIONED-PATH WCPATH > svn diff WCPATH UNVERSIONED-PATH > svn diff UNVERSIONED-PATH1 UNVERSIONED-PATH2 > > All of which are supported by 'svn diff --old=X --new=Y' (in 1.8-to-be, > not in 1.7), but not by plain 'svn diff'. > > The --old --new syntax is specific to Subversion. Many users who are > accustomed to "standard" diff commands will not try using --old and --new > (unless they've taken the time to read 'svn help diff', of course, which > apparently is too much time to ask from some users ;) > > That said, if you'd rather just print the error message instead, that's > fine with me, too. I don't care strongly enough about this to the point > where I'd say that we _must_ make this change to 'svn diff'. It's been > committed, but that doesn't mean that this has to be in 1.8.0 at all costs.
Nah, it's fine, I think I'm starting to get convinced ;-). But it's still a pity that there is no relief (at least I don't see any) for confusion around the fact that 'svn diff WC-PATH1 WC-PATH2' doesn't diff WC-PATH1 and WC-PATH2 against each other. The shorthands with the unversioned paths are quite nice I think, but there is an additional risk of confusion: 'svn diff UNVERSIONED-PATH1 UNVERSIONED-PATH2' will mean something totally different than 'svn diff WC-PATH1 WC-PATH2' (even though they could both refer to the same local files, but the commands are separated by an invocation of 'svn add'). >> Speaking of the error message: > >> How is this useful after r1442640? Seems to me we should either >> improve the error message (which would be my preferred option) *or* >> make 'svn diff' handle these automatically as a shorthand syntax >> (hence no error message). But not both. >> >> Or am I missing something? > > The error message is triggered by an invocation like: > > svn diff -c42 foo ^/trunk bar > > Which is clearly invalid usage according to 'svn help diff'. Yes, but in this case the user gives 3 targets, so he clearly couldn't have meant one of the shorthand syntaxes, right? -- Johan
