tests/test-requires.t

build: make install in "/doc" failed if the destination dir contained spaces

This and the following commits try to add the necessary quoting in the build
scripts to make the process more robust.

The target for now is rendering "make deb" successful even when the base
directory contains spaces (eg. "/opt/mercu rial").
The build process should succeed without scattering files in spurious
directories (eg.: "/opt/mercu/usr/bin/hg").

  $ hg init t
  $ cd t
  $ echo a > a
  $ hg add a
  $ hg commit -m test
  $ rm .hg/requires
  $ hg tip
  abort: unknown version (2) in revlog 00changelog.i!
  [255]
  $ echo indoor-pool > .hg/requires
  $ hg tip
  abort: repository requires features unknown to this Mercurial: indoor-pool!
  (see https://mercurial-scm.org/wiki/MissingRequirement for more information)
  [255]
  $ echo outdoor-pool >> .hg/requires
  $ hg tip
  abort: repository requires features unknown to this Mercurial: indoor-pool outdoor-pool!
  (see https://mercurial-scm.org/wiki/MissingRequirement for more information)
  [255]
  $ cd ..

Test checking between features supported locally and ones required in
another repository of push/pull/clone on localhost:

  $ mkdir supported-locally
  $ cd supported-locally

  $ hg init supported
  $ echo a > supported/a
  $ hg -R supported commit -Am '#0 at supported'
  adding a

  $ echo 'featuresetup-test' >> supported/.hg/requires
  $ cat > $TESTTMP/supported-locally/supportlocally.py <<EOF
  > from __future__ import absolute_import
  > from mercurial import extensions, localrepo
  > def featuresetup(ui, supported):
  >     for name, module in extensions.extensions(ui):
  >         if __name__ == module.__name__:
  >             # support specific feature locally
  >             supported |= {'featuresetup-test'}
  >             return
  > def uisetup(ui):
  >     localrepo.localrepository.featuresetupfuncs.add(featuresetup)
  > EOF
  $ cat > supported/.hg/hgrc <<EOF
  > [extensions]
  > # enable extension locally
  > supportlocally = $TESTTMP/supported-locally/supportlocally.py
  > EOF
  $ hg -R supported status

  $ hg init push-dst
  $ hg -R supported push push-dst
  pushing to push-dst
  abort: required features are not supported in the destination: featuresetup-test
  [255]

  $ hg init pull-src
  $ hg -R pull-src pull supported
  pulling from supported
  abort: required features are not supported in the destination: featuresetup-test
  [255]

  $ hg clone supported clone-dst
  abort: repository requires features unknown to this Mercurial: featuresetup-test!
  (see https://mercurial-scm.org/wiki/MissingRequirement for more information)
  [255]
  $ hg clone --pull supported clone-dst
  abort: required features are not supported in the destination: featuresetup-test
  [255]

  $ cd ..