tests/test-check-execute.t

copies: filter out copies from non-existent source later in _chain()

_changesetforwardcopies() repeatedly calls _chain(). That is very
expensive because _chain() does lookups in the manifest. I hope to
split up the function in two parts: 1) simple chaining, not
considering end points, and 2) filter out files that don't exist in
the end points (and ping-pong copies/renames).

This patches gets us closer to that by moving the check for
non-existent source later in the function. Now there are no more
checks for "src" and "dst" in the first loop; all the filtering of
invalid copies is done in the second loop. The code also looks much
more consistent now.

No measureable impact on `hg debugpathcopies 4.0 4.8`. That shouldn't
be surprising since the only case we're doing more checks now is in
case of chained copies/renames, which are quire rare in practice.

Differential Revision: https://phab.mercurial-scm.org/D6277

#require test-repo execbit

  $ . "$TESTDIR/helpers-testrepo.sh"
  $ cd "`dirname "$TESTDIR"`"

look for python scripts without the execute bit

  $ testrepohg files 'set:**.py and not exec() and grep(r"^#!.*?python")'
  [1]

look for python scripts with execute bit but not shebang

  $ testrepohg files 'set:**.py and exec() and not grep(r"^#!.*?python")'
  [1]

look for shell scripts with execute bit but not shebang

  $ testrepohg files 'set:**.sh and exec() and not grep(r"^#!.*(ba)?sh")'
  [1]

look for non scripts with no shebang

  $ testrepohg files 'set:exec() and not **.sh and not **.py and not grep(r"^#!")'
  [1]