tests/test-merge-internal-tools-pattern.t

debuginstall: add Python information to debuginstall output (issue4128)

This change adds to the output of "hg debuginstall" information about the
Python being used by Mercurial.  It adds both the path to the Python
executable (i.e. the value of sys.executable) and the version of Python
(specifically the major, minor, and micro versions).

Below is an example of what the output looks like after this change.
The marked lines are the new output lines:

    $ hg debuginstall
    checking encoding (UTF-8)...
 -->showing Python executable (/Users/chris/.virtualenvs/default/bin/python)
 -->showing Python version (2.7.6)
    checking Python lib (/Users/chris/.virtualenvs/default/lib/python2.7)...
    checking installed modules (/Users/chris/mercurial)...
    checking templates (/Users/chris/mercurial/templates)...
    checking commit editor...
    checking username...
    no problems detected

Note that we use the word "showing" without an ellipsis for the new lines
because, unlike the other lines (except for "Python lib" which will be
adjusted in a subsequent commit), no check follows the display of this
information.

Make sure that the internal merge tools (internal:fail, internal:local, and
internal:other) are used when matched by a merge-pattern in hgrc

Make sure HGMERGE doesn't interfere with the test:

  $ unset HGMERGE

  $ hg init

Initial file contents:

  $ echo "line 1" > f
  $ echo "line 2" >> f
  $ echo "line 3" >> f
  $ hg ci -Am "revision 0"
  adding f

  $ cat f
  line 1
  line 2
  line 3

Branch 1: editing line 1:

  $ sed 's/line 1/first line/' f > f.new
  $ mv f.new f
  $ hg ci -Am "edited first line"

Branch 2: editing line 3:

  $ hg update 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ sed 's/line 3/third line/' f > f.new
  $ mv f.new f
  $ hg ci -Am "edited third line"
  created new head

Merge using internal:fail tool:

  $ echo "[merge-patterns]" > .hg/hgrc
  $ echo "* = internal:fail" >> .hg/hgrc

  $ hg merge
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
  [1]

  $ cat f
  line 1
  line 2
  third line

  $ hg stat
  M f

Merge using internal:local tool:

  $ hg update -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ sed 's/internal:fail/internal:local/' .hg/hgrc > .hg/hgrc.new
  $ mv .hg/hgrc.new .hg/hgrc

  $ hg merge
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat f
  line 1
  line 2
  third line

  $ hg stat
  M f

Merge using internal:other tool:

  $ hg update -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ sed 's/internal:local/internal:other/' .hg/hgrc > .hg/hgrc.new
  $ mv .hg/hgrc.new .hg/hgrc

  $ hg merge
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat f
  first line
  line 2
  line 3

  $ hg stat
  M f

Merge using default tool:

  $ hg update -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm .hg/hgrc

  $ hg merge
  merging f
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat f
  first line
  line 2
  third line

  $ hg stat
  M f