foozy@708: #!/usr/bin/python
foozy@708: 
foozy@708: import re
foozy@708: 
foozy@708: def trailing_whitespace(difflines):
foozy@708:     added, linenum, header = [], 0, False
foozy@708: 
foozy@708:     for line in difflines:
foozy@708:         if header:
foozy@708:             # remember the name of the file that this diff affects
foozy@708:             m = re.match(r'(?:---|\+\+\+) ([^\t]+)', line)
foozy@708:             if m and m.group(1) != '/dev/null':
foozy@708:                 filename = m.group(1).split('/', 1)[-1]
foozy@708:             if line.startswith('+++ '):
foozy@708:                 header = False
foozy@708:             continue
foozy@708:         if line.startswith('diff '):
foozy@708:             header = True
foozy@708:             continue
foozy@708:         # hunk header - save the line number
foozy@708:         m = re.match(r'@@ -\d+,\d+ \+(\d+),', line)
foozy@708:         if m:
foozy@708:             linenum = int(m.group(1))
foozy@708:             continue
foozy@708:         # hunk body - check for an added line with trailing whitespace
foozy@708:         m = re.match(r'\+.*\s$', line)
foozy@708:         if m:
foozy@708:             added.append((filename, linenum))
foozy@708:         if line and line[0] in ' +':
foozy@708:             linenum += 1
foozy@708:     return added
foozy@708: 
foozy@708: if __name__ == '__main__':
foozy@708:     import os, sys
foozy@708:     
foozy@708:     added = trailing_whitespace(os.popen('hg export tip'))
foozy@708:     if added:
foozy@708:         for filename, linenum in added:
foozy@708:             print >> sys.stderr, ('%s, line %d: trailing whitespace added' %
foozy@708:                                   (filename, linenum))
foozy@708:         # save the commit message so we don't need to retype it
foozy@708:         os.system('hg tip --template "{desc}" > .hg/commit.save')
foozy@708:         print >> sys.stderr, 'commit message saved to .hg/commit.save'
foozy@708:         sys.exit(1)