tests: new test for mq qdiff command
`hg qdiff .' is supposed to work but it is currently broken.
This test should help us verify when it gets fixed.
Tune a bit the extdiff toplevel comments/samples.
* Capitalize the first letter of all sentences
* Add an example for GNU diff(1) 'context diff' mode.
* Explain the requirement for separate cmd.xxx and opts.xxx
options in .hgrc, which hopefully will guard against users
trying to add:
[extdiff]
# Add a new Mercurial command called `cdiff', which calls
# GNU diff(1) in 'context diff' mode.
cmd.cdiff = diff -Nprc5
which fails for recent crew builds with:
$ hg cdiff .
making snapshot of 1 files from rev
07dc4a569f4e
making snapshot of 1 files from working dir
diff -Nprc5: not found
The correct way to do this is by separating the cmd.cdiff and
opts.cdiff parts like this:
[extdiff]
# Add a new Mercurial command called `cdiff', which calls
# GNU diff(1) in 'context diff' mode.
cmd.cdiff = diff
opts.cdiff = -Nprc5
so add it as a new example and explicitly describe it in the
extdiff comments.
Fixed test-extdiff.
diff-like tools usually return 1 if differences are found.
Currently the extdiff returns 256, but that's a different topic
(consolidating return code handling in hg).