tests/test-close-head.t

discovery: only calculate closed branches if required

The number of new closed branches is required for printing in error message. So
let's only calculate them if we need to print error about new branches.

Differential Revision: https://phab.mercurial-scm.org/D6314

  $ 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 --config extensions.closehead= close-head -m 'Close old heads' -r 1 2
  $ 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]