1561 

  1562     # patch

  1563     ui.status(_("Checking patch...\n"))

  1564     patchproblems = 0

  1565     a = "1\n2\n3\n4\n"

  1566     b = "1\n2\n3\ninsert\n4\n"

  1567     fa = writetemp(a)

  1568     d = mdiff.unidiff(a, None, b, None, os.path.basename(fa),

  1569         os.path.basename(fa))

  1570     fd = writetemp(d)

  1571 

  1572     files = {}

  1573     try:

  1574         patch.patch(fd, ui, cwd=os.path.dirname(fa), files=files)

  1575     except util.Abort, e:

  1576         ui.write(_(" patch call failed:\n"))

  1577         ui.write(" " + str(e) + "\n")

  1578         patchproblems += 1

  1579     else:

  1580         if list(files) != [os.path.basename(fa)]:

  1581             ui.write(_(" unexpected patch output!\n"))

  1582             patchproblems += 1

  1583         a = open(fa).read()

  1584         if a != b:

  1585             ui.write(_(" patch test failed!\n"))

  1586             patchproblems += 1

  1587 

  1588     if patchproblems:

  1589         if ui.config('ui', 'patch'):

  1590             ui.write(_(" (Current patch tool may be incompatible with patch,"

  1591                        " or misconfigured. Please check your configuration"

  1592                        " file)\n"))

  1593         else:

  1594             ui.write(_(" Internal patcher failure, please report this error"

  1595                        " to http://mercurial.selenic.com/wiki/BugTracker\n"))

  1596     problems += patchproblems

  1597 

  1598     os.unlink(fa)

  1599     os.unlink(fd)