igor@333: #!/usr/bin/python
igor@333: 
igor@333: import re
igor@333: 
igor@333: def trailing_whitespace(difflines):
igor@333:     added, linenum, header = [], 0, False
igor@333: 
igor@333:     for line in difflines:
igor@333:         if header:
igor@333:             # remember the name of the file that this diff affects
igor@333:             m = re.match(r'(?:---|\+\+\+) ([^\t]+)', line)
igor@333:             if m and m.group(1) != '/dev/null':
igor@333:                 filename = m.group(1).split('/', 1)[-1]
igor@333:             if line.startswith('+++ '):
igor@333:                 header = False
igor@333:             continue
igor@333:         if line.startswith('diff '):
igor@333:             header = True
igor@333:             continue
igor@333:         # hunk header - save the line number
igor@333:         m = re.match(r'@@ -\d+,\d+ \+(\d+),', line)
igor@333:         if m:
igor@333:             linenum = int(m.group(1))
igor@333:             continue
igor@333:         # hunk body - check for an added line with trailing whitespace
igor@333:         m = re.match(r'\+.*\s$', line)
igor@333:         if m:
igor@333:             added.append((filename, linenum))
igor@333:         if line and line[0] in ' +':
igor@333:             linenum += 1
igor@333:     return added
igor@333: 
igor@333: if __name__ == '__main__':
igor@333:     import os, sys
igor@333:     
igor@333:     added = trailing_whitespace(os.popen('hg export tip'))
igor@333:     if added:
igor@333:         for filename, linenum in added:
igor@333:             print >> sys.stderr, ('%s, line %d: trailing whitespace added' %
igor@333:                                   (filename, linenum))
igor@333:         # save the commit message so we don't need to retype it
igor@333:         os.system('hg tip --template "{desc}" > .hg/commit.save')
igor@333:         print >> sys.stderr, 'commit message saved to .hg/commit.save'
igor@333:         sys.exit(1)