tests/test-impexp-branch.t

hghave: add "chg" flag to skip tests that can't be compatible with chg

Several tests fail with chg for several reasons such as loaded chgserver
extension, running uisetup() per server instead of per runcommand, etc.
Since these tests can't/shouldn't be changed to be chg friendly, we need
a flag to skip them.

This patch explicitly drops CHGHG environment if chg isn't involved. This
way, hghave can just check if CHGHG exists.

  $ echo '[extensions]' >> $HGRCPATH
  $ echo 'strip =' >> $HGRCPATH

  $ cat >findbranch.py <<EOF
  > import re, sys
  > 
  > head_re = re.compile('^#(?:(?:\\s+([A-Za-z][A-Za-z0-9_]*)(?:\\s.*)?)|(?:\\s*))$')
  > 
  > for line in sys.stdin:
  >     hmatch = head_re.match(line)
  >     if not hmatch:
  >         sys.exit(1)
  >     if hmatch.group(1) == 'Branch':
  >         sys.exit(0)
  > sys.exit(1)
  > EOF

  $ hg init a
  $ cd a
  $ echo "Rev 1" >rev
  $ hg add rev
  $ hg commit -m "No branch."
  $ hg branch abranch
  marked working directory as branch abranch
  (branches are permanent and global, did you want a bookmark?)
  $ echo "Rev  2" >rev
  $ hg commit -m "With branch."

  $ hg export 0 > ../r0.patch
  $ hg export 1 > ../r1.patch
  $ cd ..

  $ if python findbranch.py < r0.patch; then
  >     echo "Export of default branch revision has Branch header" 1>&2
  >     exit 1
  > fi

  $ if python findbranch.py < r1.patch; then
  >     :  # Do nothing
  > else
  >     echo "Export of branch revision is missing Branch header" 1>&2
  >     exit 1
  > fi

Make sure import still works with branch information in patches.

  $ hg init b
  $ cd b
  $ hg import ../r0.patch
  applying ../r0.patch
  $ hg import ../r1.patch
  applying ../r1.patch
  $ cd ..

  $ hg init c
  $ cd c
  $ hg import --exact --no-commit ../r0.patch
  applying ../r0.patch
  warning: can't check exact import with --no-commit
  $ hg st
  A rev
  $ hg revert -a
  forgetting rev
  $ rm rev
  $ hg import --exact ../r0.patch
  applying ../r0.patch
  $ hg import --exact ../r1.patch
  applying ../r1.patch

Test --exact and patch header separators (issue3356)

  $ hg strip --no-backup .
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  >>> import re
  >>> p = file('../r1.patch', 'rb').read()
  >>> p = re.sub(r'Parent\s+', 'Parent ', p)
  >>> file('../r1-ws.patch', 'wb').write(p)
  $ hg import --exact ../r1-ws.patch
  applying ../r1-ws.patch

  $ cd ..