tests/test-check-execute.t

transaction: avoid ambiguity of file stat at restoring from backup

In some cases below, copying from backup is used to restore original
contents of a file, which is backuped via addfilegenerator(). If
copying keeps ctime, mtime and size of a file, restoring is
overlooked, and old contents cached before restoring isn't invalidated
as expected.

  - failure of transaction (from '.hg/journal.backup.*')
  - rollback of previous transaction (from '.hg/undo.backup.*')

To avoid ambiguity of file stat at restoring, this patch invokes
util.copyfile() with checkambig=True.

This patch is a part of "Exact Cache Validation Plan":

    https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan

#require test-repo execbit

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

look for python scripts without the execute bit

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

look for python scripts with execute bit but not shebang

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

look for shell scripts with execute bit but not shebang

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

look for non scripts with no shebang

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