problem with extdiff extension

[Matt Mackall]

On Tue, 2011-08-23 at 00:14 -0700, James Walker wrote:
> On 8/22/11 10:33 AM, Mads Kiilerich wrote:
> > On 08/22/2011 07:16 PM, James Walker wrote:
> >> On 8/22/11 9:58 AM, Mads Kiilerich wrote:
> >>> On 08/22/2011 06:25 PM, James Walker wrote:
> >>>> The extdiff extension is not working for me lately, depending on which
> >>>> arguments I pass. I'm using hg version 1.9.1 on Mac OS X 10.6.8. My
> >>>> .hgrc enables extdiff and then configures it as follows:
> >>>>
> >>>> [extdiff]
> >>>> cmd.bbdiff=/usr/bin/bbdiff
> >>>> opts.bbdiff=--wait --resume --reverse
> >>>>
> >>>> Here bbdiff is a command that invokes the BBEdit text editor.
> >>>>
> >>>> If I say
> >>>>
> >>>> hg bbdiff Source/StatusController.mm
> >>>>
> >>>> then it works correctly. If I say
> >>>>
> >>>> hg bbdiff -r 53 Source/StatusController.mm
> >>>>
> >>>> then I get
> >>>>
> >>>> bbdiff: error: -36
> >>>>
> >>>> where -36 is a Mac OS code that means I/O error. And if I say
> >>>>
> >>>> hg bbdiff -r 53 -r 56 Source/StatusController.mm
> >>>>
> >>>> then there is no response at all.
> >>>>
> >>>> I suppose there could be a bug in bbdiff or BBEdit, which have been
> >>>> updated about as recently as Mercurial, but I'm not sure how bbdiff
> >>>> could tell the difference between these 3 cases. In each case, it
> >>>> should
> >>>> just be receiving 2 files.
> >>>>
> >>>> Any suggestions on how to proceed?
> >>>
> >>> Try to add
> >>> --debug --traceback
> >>> when you run hg and see if that gives a hint.
> >>
> >> OK, thanks...
> >>
> >> hg --debug --traceback bbdiff -r 53 -r 56 Source/StatusController.mm
> >>
> >> still produces no output at all, but
> >>
> >> hg --debug --traceback bbdiff -r 53 Source/StatusController.mm
> >>
> >> produces:
> >>
> >> making snapshot of 0 files from rev 55eb4c5075e3
> >> running "'/usr/bin/bbdiff' --wait --resume --reverse '/dev/null'
> >> '/Volumes/Work2/mercurial/MacMerc/Source/StatusController.mm'" in
> >> /var/folders/vF/vFOjdRypG88ctSvpPVHqlU+++TI/-Tmp-/extdiff.1TtmZb
> >> bbdiff: error: -36
> >> cleaning up temp directory
> >>
> >> Aha, apparently the file got renamed into a different directory in
> >> revision 102, so it's not being found in revisions 53 and 56.
> >
> > Are you sure this problem is related to upgrading Mercurial?
> 
> 
> Not at all.  It is certainly possible that this is the first time I ever 
> tried doing a diff of a file that had been moved, using a revision from 
> before the move.
> 
> 
> > Anyway, feel free to file it in the bugtracker - with an example of how
> > it can be reproduced.
> 
> 
> Maybe it's more of a feature request, that Mercurial do a better job of 
> tracking files through moves and renames.

It does a fine job. But generally speaking, there's no way to
communicate that information to a third-party diff tool.

> Or failing that, I wish I knew some way to take a current pathname and a 
> revision, and ask Mercurial: What was the pathname, if any, of this file 
> at that revision?

The most straightforward way is:

hg log -vf filename

-- 
Mathematics is the supreme nostalgia of our time.