tests/test-mac-packages.t

perf: introduce safeattrsetter to replace direct attribute assignment

Referring not-existing attribute immediately causes failure, but
assigning a value to such attribute doesn't.

For example, perf.py has code paths below, which assign a value to
not-existing attribute. This causes incorrect performance measurement,
but these code paths are executed successfully.

  - "repo._tags = None" in perftags()
    recent Mercurial has tags cache information in repo._tagscache

  - "branchmap.write = lambda repo: None" in perfbranchmap()
    branchmap cache is written out by branchcache.write() in branchmap.py

"util.safehasattr() before assignment" can avoid this issue, but might
increase mistake at "copy & paste" attribute name or so.

To centralize (1) examining existence of, (2) assigning a value to,
and (3) restoring an old value to the attribute, this patch introduces
safeattrsetter(). This is used to replace direct attribute assignment
in subsequent patches.

Encapsulation of restoring is needed to completely remove direct
attribute assignment from perf.py, even though restoring isn't needed
so often.

#require test-repo slow osx osxpackaging

  $ . "$TESTDIR/helpers-testrepo.sh"

  $ OUTPUTDIR=`pwd`
  $ export OUTPUTDIR
  $ KEEPMPKG=yes
  $ export KEEPMPKG

  $ cd "$TESTDIR"/..
  $ rm -rf dist
  $ make osx > $OUTPUTDIR/build.log 2>&1
  $ cd $OUTPUTDIR
  $ ls -d *.pkg
  Mercurial-*-macosx10.*.pkg (glob)

  $ xar -xf Mercurial*.pkg

Gather list of all installed files:
  $ lsbom mercurial.pkg/Bom > boms.txt

Spot-check some randomly selected files:
  $ grep bdiff boms.txt | cut -d '	' -f 1,2,3
  ./Library/Python/2.7/site-packages/mercurial/bdiff.so	100755	0/0
  ./Library/Python/2.7/site-packages/mercurial/pure/bdiff.py	100644	0/0
  ./Library/Python/2.7/site-packages/mercurial/pure/bdiff.pyc	100644	0/0
  ./Library/Python/2.7/site-packages/mercurial/pure/bdiff.pyo	100644	0/0
  $ egrep 'man[15]' boms.txt | cut -d '	' -f 1,2,3
  ./usr/local/share/man/man1	40755	0/0
  ./usr/local/share/man/man1/hg.1	100644	0/0
  ./usr/local/share/man/man5	40755	0/0
  ./usr/local/share/man/man5/hgignore.5	100644	0/0
  ./usr/local/share/man/man5/hgrc.5	100644	0/0
  $ grep bser boms.txt | cut -d '	' -f 1,2,3
  ./Library/Python/2.7/site-packages/hgext/fsmonitor/pywatchman/bser.so	100755	0/0
  ./Library/Python/2.7/site-packages/hgext/fsmonitor/pywatchman/pybser.py	100644	0/0
  ./Library/Python/2.7/site-packages/hgext/fsmonitor/pywatchman/pybser.pyc	100644	0/0
  ./Library/Python/2.7/site-packages/hgext/fsmonitor/pywatchman/pybser.pyo	100644	0/0
  $ grep localrepo boms.txt | cut -d '	' -f 1,2,3
  ./Library/Python/2.7/site-packages/mercurial/localrepo.py	100644	0/0
  ./Library/Python/2.7/site-packages/mercurial/localrepo.pyc	100644	0/0
  ./Library/Python/2.7/site-packages/mercurial/localrepo.pyo	100644	0/0
  $ grep '/hg	' boms.txt | cut -d '	' -f 1,2,3
  ./usr/local/bin/hg	100755	0/0

Make sure the built binary uses the system Python interpreter
  $ bsdtar xf mercurial.pkg/Payload usr/local/bin
Use a glob to find this to avoid check-code whining about a fixed path.
  $ head -n 1 usr/local/b?n/hg
  #!/System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python

Note that we're not currently installing any /etc/mercurial stuff,
including merge-tool configurations.