Mercurial > hg > mercurial-crew-with-dirclash
view mercurial/mdiff.py @ 5192:33015dac5df5
convert: fix mercurial_sink.putcommit
Changeset 4ebc8693ce72 added some code to putcommit to avoid creating a
revision that touches no files, but this can break regular conversions
from some repositories:
- conceptually, since we're converting a repo, we should try to make
the new hg repo as similar as possible to the original repo - we
should create a new changeset, even if the original revision didn't
touch any files (maybe the commit message had some important bit);
- even if a "regular" revision that doesn't touch any file may seem
weird (and maybe even broken), it's completely legitimate for a merge
revision to not touch any file, and, if we just skip it, the
converted repo will end up with wrong history and possibly an extra
head.
As an example, say the crew and main hg repos are sync'ed. Somebody
sends an important patch to the mailing list. Matt quickly applies
and pushes it. But at the same time somebody also applies it to crew
and pushes it. Suppose the commit message ended up being a bit
different (say, there was a typo and somebody didn't fix it) or that
the date ended up being different (because of different patch-applying
scripts): the changeset hashes will be different, but the manifests
will be the same.
Since both changesets were pushed to public repos, it's hard to recall
them. If both are merged, the manifest from the resulting merge
revision will have the exact same contents as its parents - i.e. the
merge revision really doesn't touch any file at all.
To keep the file filtering stuff "working", the generic code was changed
to skip empty revisions if we're filtering the repo, fixing a bug in the
process (we want parents[0] instead of tip).
author | Alexis S. L. Carvalho <alexis@cecm.usp.br> |
---|---|
date | Fri, 17 Aug 2007 20:18:05 -0300 |
parents | 372d93f03d3a |
children | 7530334bf301 |
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# mdiff.py - diff and patch routines for mercurial # # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms # of the GNU General Public License, incorporated herein by reference. import bdiff, mpatch, re, struct, util, md5 def splitnewlines(text): '''like str.splitlines, but only split on newlines.''' lines = [l + '\n' for l in text.split('\n')] if lines: if lines[-1] == '\n': lines.pop() else: lines[-1] = lines[-1][:-1] return lines class diffopts(object): '''context is the number of context lines text treats all files as text showfunc enables diff -p output git enables the git extended patch format nodates removes dates from diff headers ignorews ignores all whitespace changes in the diff ignorewsamount ignores changes in the amount of whitespace ignoreblanklines ignores changes whose lines are all blank''' defaults = { 'context': 3, 'text': False, 'showfunc': True, 'git': False, 'nodates': False, 'ignorews': False, 'ignorewsamount': False, 'ignoreblanklines': False, } __slots__ = defaults.keys() def __init__(self, **opts): for k in self.__slots__: v = opts.get(k) if v is None: v = self.defaults[k] setattr(self, k, v) defaultopts = diffopts() def wsclean(opts, text): if opts.ignorews: text = re.sub('[ \t]+', '', text) elif opts.ignorewsamount: text = re.sub('[ \t]+', ' ', text) text = re.sub('[ \t]+\n', '\n', text) if opts.ignoreblanklines: text = re.sub('\n+', '', text) return text def unidiff(a, ad, b, bd, fn, r=None, opts=defaultopts): def datetag(date, addtab=True): if not opts.git and not opts.nodates: return '\t%s\n' % date if addtab and ' ' in fn: return '\t\n' return '\n' if not a and not b: return "" epoch = util.datestr((0, 0)) if not opts.text and (util.binary(a) or util.binary(b)): def h(v): # md5 is used instead of sha1 because md5 is supposedly faster return md5.new(v).digest() if a and b and len(a) == len(b) and h(a) == h(b): return "" l = ['Binary file %s has changed\n' % fn] elif not a: b = splitnewlines(b) if a is None: l1 = '--- /dev/null%s' % datetag(epoch, False) else: l1 = "--- %s%s" % ("a/" + fn, datetag(ad)) l2 = "+++ %s%s" % ("b/" + fn, datetag(bd)) l3 = "@@ -0,0 +1,%d @@\n" % len(b) l = [l1, l2, l3] + ["+" + e for e in b] elif not b: a = splitnewlines(a) l1 = "--- %s%s" % ("a/" + fn, datetag(ad)) if b is None: l2 = '+++ /dev/null%s' % datetag(epoch, False) else: l2 = "+++ %s%s" % ("b/" + fn, datetag(bd)) l3 = "@@ -1,%d +0,0 @@\n" % len(a) l = [l1, l2, l3] + ["-" + e for e in a] else: al = splitnewlines(a) bl = splitnewlines(b) l = list(bunidiff(a, b, al, bl, "a/" + fn, "b/" + fn, opts=opts)) if not l: return "" # difflib uses a space, rather than a tab l[0] = "%s%s" % (l[0][:-2], datetag(ad)) l[1] = "%s%s" % (l[1][:-2], datetag(bd)) for ln in xrange(len(l)): if l[ln][-1] != '\n': l[ln] += "\n\ No newline at end of file\n" if r: l.insert(0, "diff %s %s\n" % (' '.join(["-r %s" % rev for rev in r]), fn)) return "".join(l) # somewhat self contained replacement for difflib.unified_diff # t1 and t2 are the text to be diffed # l1 and l2 are the text broken up into lines # header1 and header2 are the filenames for the diff output def bunidiff(t1, t2, l1, l2, header1, header2, opts=defaultopts): def contextend(l, len): ret = l + opts.context if ret > len: ret = len return ret def contextstart(l): ret = l - opts.context if ret < 0: return 0 return ret def yieldhunk(hunk, header): if header: for x in header: yield x (astart, a2, bstart, b2, delta) = hunk aend = contextend(a2, len(l1)) alen = aend - astart blen = b2 - bstart + aend - a2 func = "" if opts.showfunc: # walk backwards from the start of the context # to find a line starting with an alphanumeric char. for x in xrange(astart, -1, -1): t = l1[x].rstrip() if funcre.match(t): func = ' ' + t[:40] break yield "@@ -%d,%d +%d,%d @@%s\n" % (astart + 1, alen, bstart + 1, blen, func) for x in delta: yield x for x in xrange(a2, aend): yield ' ' + l1[x] header = [ "--- %s\t\n" % header1, "+++ %s\t\n" % header2 ] if opts.showfunc: funcre = re.compile('\w') # bdiff.blocks gives us the matching sequences in the files. The loop # below finds the spaces between those matching sequences and translates # them into diff output. # diff = bdiff.blocks(t1, t2) hunk = None for i in xrange(len(diff)): # The first match is special. # we've either found a match starting at line 0 or a match later # in the file. If it starts later, old and new below will both be # empty and we'll continue to the next match. if i > 0: s = diff[i-1] else: s = [0, 0, 0, 0] delta = [] s1 = diff[i] a1 = s[1] a2 = s1[0] b1 = s[3] b2 = s1[2] old = l1[a1:a2] new = l2[b1:b2] # bdiff sometimes gives huge matches past eof, this check eats them, # and deals with the special first match case described above if not old and not new: continue if opts.ignorews or opts.ignorewsamount or opts.ignoreblanklines: if wsclean(opts, "".join(old)) == wsclean(opts, "".join(new)): continue astart = contextstart(a1) bstart = contextstart(b1) prev = None if hunk: # join with the previous hunk if it falls inside the context if astart < hunk[1] + opts.context + 1: prev = hunk astart = hunk[1] bstart = hunk[3] else: for x in yieldhunk(hunk, header): yield x # we only want to yield the header if the files differ, and # we only want to yield it once. header = None if prev: # we've joined the previous hunk, record the new ending points. hunk[1] = a2 hunk[3] = b2 delta = hunk[4] else: # create a new hunk hunk = [ astart, a2, bstart, b2, delta ] delta[len(delta):] = [ ' ' + x for x in l1[astart:a1] ] delta[len(delta):] = [ '-' + x for x in old ] delta[len(delta):] = [ '+' + x for x in new ] if hunk: for x in yieldhunk(hunk, header): yield x def patchtext(bin): pos = 0 t = [] while pos < len(bin): p1, p2, l = struct.unpack(">lll", bin[pos:pos + 12]) pos += 12 t.append(bin[pos:pos + l]) pos += l return "".join(t) def patch(a, bin): return mpatch.patches(a, [bin]) # similar to difflib.SequenceMatcher.get_matching_blocks def get_matching_blocks(a, b): return [(d[0], d[2], d[1] - d[0]) for d in bdiff.blocks(a, b)] patches = mpatch.patches patchedsize = mpatch.patchedsize textdiff = bdiff.bdiff