match: strengthen visit_children_set invariant, Recursive means "all files"
My previous interpretation of "Recursive" was too relaxed: I thought it
instructed the caller to do something like this:
> you can stop calling `visit_children_set` because you'll need to descend into
> every directory recursively, but you should still check every file if it
> matches or not
Whereas the real instruction seems to be:
> I guarantee that everything in this subtree matches, you can stop
> querying the matcher for all files and dirs altogether.
The evidence to support this:
- the test actually passes with the stronger invariant, revealing no
exceptions from this rule
- the implementation of `visit_children_set` for `DifferenceMatcher`
clearly relies on this requirement, so it must hold for that not to
lead to bugs.
# Read the output of a "svn log --xml" command on stdin, parse it and
# print a subset of attributes common to all svn versions tested by
# hg.
import sys
import xml.dom.minidom
def xmltext(e):
return ''.join(c.data for c in e.childNodes if c.nodeType == c.TEXT_NODE)
def parseentry(entry):
e = {}
e['revision'] = entry.getAttribute('revision')
e['author'] = xmltext(entry.getElementsByTagName('author')[0])
e['msg'] = xmltext(entry.getElementsByTagName('msg')[0])
e['date'] = xmltext(entry.getElementsByTagName('date')[0])
e['paths'] = []
paths = entry.getElementsByTagName('paths')
if paths:
paths = paths[0]
for p in paths.getElementsByTagName('path'):
action = p.getAttribute('action').encode('utf-8')
path = xmltext(p).encode('utf-8')
frompath = p.getAttribute('copyfrom-path').encode('utf-8')
fromrev = p.getAttribute('copyfrom-rev').encode('utf-8')
e['paths'].append((path, action, frompath, fromrev))
return e
def parselog(data):
entries = []
doc = xml.dom.minidom.parseString(data)
for e in doc.getElementsByTagName('logentry'):
entries.append(parseentry(e))
return entries
def printentries(entries):
try:
fp = sys.stdout.buffer
except AttributeError:
fp = sys.stdout
for e in entries:
for k in ('revision', 'author', 'date', 'msg'):
fp.write(('%s: %s\n' % (k, e[k])).encode('utf-8'))
for path, action, fpath, frev in sorted(e['paths']):
frominfo = b''
if frev:
frominfo = b' (from %s@%s)' % (fpath, frev)
p = b' %s %s%s\n' % (action, path, frominfo)
fp.write(p)
if __name__ == '__main__':
data = sys.stdin.read()
entries = parselog(data)
printentries(entries)