shelve: teach new shelf class to check if .shelve file exists
This removes the only remaining use for `shelvedfile`, so the class
now goes away.
Differential Revision: https://phab.mercurial-scm.org/D9713
$ hg init test-content
$ cd test-content
$ hg debugbuilddag '+2*2*3*4+7'
$ hg bookmark -r 1 @
$ hg log -G --template '{rev}:{node|short}'
o 11:1d876b1f862c
|
o 10:ea5f71948eb8
|
o 9:f1b0356d867a
|
o 8:e8d1253fb0d7
|
o 7:d423bbba4459
|
o 6:a2f58e9c1e56
|
o 5:3a367db1fabc
|
o 4:e7bd5218ca15
|
| o 3:6100d3090acf
|/
| o 2:fa942426a6fd
|/
| o 1:66f7d451a68b
|/
o 0:1ea73414a91b
$ hg --config extensions.closehead= close-head -m 'Not a head' 0 1
abort: revision is not an open head: 0
[255]
$ hg --config extensions.closehead= close-head -m 'Not a head' -r 0 1
abort: revision is not an open head: 0
[255]
$ hg id
000000000000
$ hg --config extensions.closehead= close-head -m 'Close old heads' -r 1 2
$ hg id
000000000000
$ hg bookmark
@ 1:66f7d451a68b
$ hg heads
changeset: 11:1d876b1f862c
user: debugbuilddag
date: Thu Jan 01 00:00:11 1970 +0000
summary: r11
changeset: 3:6100d3090acf
parent: 0:1ea73414a91b
user: debugbuilddag
date: Thu Jan 01 00:00:03 1970 +0000
summary: r3
$ hg --config extensions.closehead= close-head -m 'Close more old heads' -r 11
$ hg heads
changeset: 3:6100d3090acf
parent: 0:1ea73414a91b
user: debugbuilddag
date: Thu Jan 01 00:00:03 1970 +0000
summary: r3
$ hg --config extensions.closehead= close-head -m 'Not a head' 0
abort: revision is not an open head: 0
[255]
$ hg --config extensions.closehead= close-head -m 'Already closed head' 1
abort: revision is not an open head: 1
[255]
$ hg init ../test-empty
$ cd ../test-empty
$ hg debugbuilddag '+1'
$ hg log -G --template '{rev}:{node|short}'
o 0:1ea73414a91b
$ hg --config extensions.closehead= close-head -m 'Close initial revision' 0
$ hg heads
[1]