git-hgext: adjust to the lack of `changelog.heads` method
We don't have a `heads` method returning nodeid, but this is very easy to get
the same result.
This was flagged by pytype.
We can note that the fact this code did not break is probably a good sign that
it is dead code.
However this is a question outside of the scop of this series.
$ 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]