Re: [Bug-vc-dwim] vc-dwim 1.5: external diff died

[Bruno Haible]

Hi Jim,

> Perhaps GIT_EXTERNAL_DIFF is still set in the environment?

I had unset it in the command line just before invoking vc-dwim.
You can see from the previous command (with "git diff") that this
'unset' command works as expected.

I had modified my copy of vc-dwim like this:

BEGIN
{
  my $perllibdir = $ENV{'perllibdir'} || '/arch/x86-linux/gnu/share/vc-dwim';
  unshift @INC, (split ':', $perllibdir);

  # Override SHELL.  This is required on DJGPP so that system() uses
  # bash, not COMMAND.COM which doesn't quote arguments properly.
  # Other systems aren't expected to use $SHELL when Automake
  # runs, but it should be safe to drop the `if DJGPP' guard if
  # it turns up other systems need the same thing.  After all,
  # if SHELL is used, ./configure's SHELL is always better than
  # the user's SHELL (which may be something like tcsh).
  $ENV{'SHELL'} = '/bin/sh' if exists $ENV{'DJGPP'};

  undef $ENV{'GIT_EXTERNAL_DIFF'};
}

Apparently this last statement is causing the trouble.

Admittedly I am trying to modify code that I don't understand - until
the problem I reported yesterday gets fixed upstream.

When I remove that hack, now I get reasonable output from 'vc-dwim':

$ (unset GIT_EXTERNAL_DIFF ; vc-dwim)
vc-dwim: lib/relocatable.c is listed in the ChangeLog entry, but not in diffs.
Did you forget to add it?

But without the 'unset' command, vc-dwim does not recognize the diff format,
like you predicted:

$ vc-dwim
vc-dwim: ChangeLog contains no newly added lines

Bruno