1 #!/usr/bin/env python

2 #

3 # save as .hg/check_whitespace.py and make executable

4

5 import re

6

7 def trailing_whitespace(difflines):

8 #

9 linenum, header = 0, False

10

11 for line in difflines:

12 if header:

13 # remember the name of the file that this diff affects

14 m = re.match(r'(?:---|\+\+\+) ([^\t]+)', line)

15 if m and m.group(1) != '/dev/null':

16 filename = m.group(1).split('/', 1)[-1]

17 if line.startswith('+++ '):

18 header = False

19 continue

20 if line.startswith('diff '):

21 header = True

22 continue

23 # hunk header - save the line number

24 m = re.match(r'@@ -\d+,\d+ \+(\d+),', line)

25 if m:

26 linenum = int(m.group(1))

27 continue

28 # hunk body - check for an added line with trailing whitespace

29 m = re.match(r'\+.*\s$', line)

30 if m:

31 yield filename, linenum

32 if line and line[0] in ' +':

33 linenum += 1

34

35 if __name__ == '__main__':

36 import os, sys

37

38 added = 0

39 for filename, linenum in trailing_whitespace(os.popen('hg export tip')):

40 print >> sys.stderr, ('%s, line %d: trailing whitespace added' %

41 (filename, linenum))

42 added += 1

43 if added:

44 # save the commit message so we don't need to retype it

45 os.system('hg tip --template "{desc}" > .hg/commit.save')

46 print >> sys.stderr, 'commit message saved to .hg/commit.save'

47 sys.exit(1)