pyproject: add config file
This will tell pip et al to call our setup.py for the majority of
packaging concerns, but also gives us a place to put standard config
stuff like black.
This was previously D9833, but was rolled back due to test
breakage. nbjoerg thinks that breakage is now resolved, so we're
trying again.
Differential Revision: https://phab.mercurial-scm.org/D10184
#require no-icasefs
test file addition with colliding case
$ hg init repo1
$ cd repo1
$ echo a > a
$ echo A > A
$ hg add a
$ hg st
A a
? A
$ hg add --config ui.portablefilenames=abort A
abort: possible case-folding collision for A
[255]
$ hg st
A a
? A
$ hg add A
warning: possible case-folding collision for A
$ hg st
A A
A a
$ hg forget A
$ hg st
A a
? A
$ hg add --config ui.portablefilenames=no A
$ hg st
A A
A a
$ mkdir b
$ touch b/c b/D
$ hg add b
adding b/D
adding b/c
$ touch b/d b/C
$ hg add b/C
warning: possible case-folding collision for b/C
$ hg add b/d
warning: possible case-folding collision for b/d
$ touch b/a1 b/a2
$ hg add b
adding b/a1
adding b/a2
$ touch b/A2 b/a1.1
$ hg add b/a1.1 b/A2
warning: possible case-folding collision for b/A2
$ touch b/f b/F
$ hg add b/f b/F
warning: possible case-folding collision for b/f
$ touch g G
$ hg add g G
warning: possible case-folding collision for g
$ mkdir h H
$ touch h/x H/x
$ hg add h/x H/x
warning: possible case-folding collision for h/x
$ touch h/s H/s
$ hg add h/s
$ hg add H/s
warning: possible case-folding collision for H/s
case changing rename must not warn or abort
$ echo c > c
$ hg ci -qAmx
$ hg mv c C
$ cd ..