+
−#!/usr/bin/env python
+
−#
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−# Mercurial hook to check for inappropriate whitespace.  Currently it
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−# only checks Python files.
+
−#
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−# This script is based on the code in the Mercurial book
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−# <http://hgbook.red-bean.com/read/handling-repository-events-with-hooks.html#id403945>
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−
+
−import re
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−
+
−def trailing_whitespace(difflines):
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−    linenum = 0
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−    header = False
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−    filename = ''
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−    fnre = re.compile(r'(?:---|\+\+\+) (?P<filename>[^\t\r\n]+)')
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−    lnre = re.compile(r'@@ -\d+,\d+ \+(?P<lineno>\d+),')
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−    wsre = re.compile(r'\+.*[ \t]$')
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−    tbre = re.compile(r'\+.*\t')
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−
+
−    for line in difflines:
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−        if header:
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−            # remember the name of the file that this diff affects
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−            m = fnre.match(line)
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−            if m is not None and m.group('filename') != '/dev/null':
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−                filename = m.group('filename').split('/', 1)[-1]
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−            if line.startswith('+++ '):
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−                header = False
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−            continue
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−        if line.startswith('diff '):
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−            header = True
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−            continue
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−        # hunk header - save the line number
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−        m = lnre.match(line)
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−        if m is not None:
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−            linenum = int(m.group('lineno'))
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−            continue
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−        if header or not filename:
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−            continue
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−        # hunk body - check for an added line with bad whitespace
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−        if filename[-3:] == '.py' or filename[-5:] == '.py.in':
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−            m = tbre.match(line)
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−            if m is not None:
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−                yield filename, linenum, 'TABs'
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−        m = wsre.match(line)
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−        if m is not None:
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−            if filename[-3:] == '.py' or filename[-5:] == '.py.in':
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−                yield filename, linenum, 'trailing whitespace'
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−        if line and line[0] in ' +':
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−            linenum += 1
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−
+
−if __name__ == '__main__':
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−    import os, sys, subprocess
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−
+
−    added = 0
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−    for filename, linenum, msg in trailing_whitespace(subprocess.Popen(['hg', 'export', 'tip'], stdout=subprocess.PIPE).stdout):
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−        print >> sys.stderr, ('%s, line %d: %s added' %
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−                              (filename, linenum, msg))
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−        added += 1
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−    if added:
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−        # save the commit message so we don't need to retype it
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−        cmtsv = os.path.join('.hg','commit.save')
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−        subprocess.call(['hg', 'tip', '--template', '{desc}'],
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−                        stdout=open(cmtsv, 'w'))
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−        print >> sys.stderr, 'commit message saved to %s' % cmtsv
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−        sys.exit(1)