view tests/test-parseindex.t @ 26228:0fd20a71abdb

extdiff: add a --patch argument for diffing changeset deltas

One of the things I missed the most when transitioning from versioned MQ to
evolve was the loss of being able to check that rebase conflicts were properly
resolved by:

  $ hg ci --mq -m "before"
  $ hg rebase -s qbase -d tip
  $ hg bcompare --mq

The old csets stay in the tree with evolve, but a straight diff includes all of
the other changes that were pulled in, obscuring the code that was rebased.
Diffing deltas can be confusing, but unless radical changes were made during the
resolve, it is very clear when individual hunks are added, dropped or modified.
Unlike the MQ technique, this can only compare a single pair of csets/patches at
a time.  Like the MQ method, this also highlights changes in the commit comment
and other metadata.

I originally tried monkey patching from the evolve extension, but that is too
complicated given that it depends on the order the two different extensions are
loaded.  This functionality is also useful when comparing grafts however, so
implementing it in the core is more than just convenience.

The --change argument doesn't make much sense for this, but it isn't harmful so
I didn't bother blocking it.  The -I/-X options are ignored because of a
limitation of cmdutil.export().  We'll fix that next.

revlog.parseindex must be able to parse the index file even if
an index entry is split between two 64k blocks.  The ideal test
would be to create an index file with inline data where
64k < size < 64k + 64 (64k is the size of the read buffer, 64 is
the size of an index entry) and with an index entry starting right
before the 64k block boundary, and try to read it.
We approximate that by reducing the read buffer to 1 byte.

  $ hg init a
  $ cd a
  $ echo abc > foo
  $ hg add foo
  $ hg commit -m 'add foo'
  $ echo >> foo
  $ hg commit -m 'change foo'
  $ hg log -r 0:
  changeset:   0:7c31755bf9b5
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo
  
  changeset:   1:26333235a41c
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change foo
  
  $ cat >> test.py << EOF
  > from mercurial import changelog, scmutil
  > from mercurial.node import *
  > 
  > class singlebyteread(object):
  >     def __init__(self, real):
  >         self.real = real
  > 
  >     def read(self, size=-1):
  >         if size == 65536:
  >             size = 1
  >         return self.real.read(size)
  > 
  >     def __getattr__(self, key):
  >         return getattr(self.real, key)
  > 
  > def opener(*args):
  >     o = scmutil.opener(*args)
  >     def wrapper(*a):
  >         f = o(*a)
  >         return singlebyteread(f)
  >     return wrapper
  > 
  > cl = changelog.changelog(opener('.hg/store'))
  > print len(cl), 'revisions:'
  > for r in cl:
  >     print short(cl.node(r))
  > EOF
  $ python test.py
  2 revisions:
  7c31755bf9b5
  26333235a41c

  $ cd ..

#if no-pure

Test SEGV caused by bad revision passed to reachableroots() (issue4775):

  $ cd a

  $ python <<EOF
  > from mercurial import changelog, scmutil
  > cl = changelog.changelog(scmutil.vfs('.hg/store'))
  > print 'good heads:'
  > for head in [0, len(cl) - 1, -1]:
  >     print'%s: %r' % (head, cl.reachableroots(0, [head], [0]))
  > print 'bad heads:'
  > for head in [len(cl), 10000, -2, -10000, None]:
  >     print '%s:' % head,
  >     try:
  >         cl.reachableroots(0, [head], [0])
  >         print 'uncaught buffer overflow?'
  >     except (IndexError, TypeError) as inst:
  >         print inst
  > print 'good roots:'
  > for root in [0, len(cl) - 1, -1]:
  >     print '%s: %r' % (root, cl.reachableroots(root, [len(cl) - 1], [root]))
  > print 'out-of-range roots are ignored:'
  > for root in [len(cl), 10000, -2, -10000]:
  >     print '%s: %r' % (root, cl.reachableroots(root, [len(cl) - 1], [root]))
  > print 'bad roots:'
  > for root in [None]:
  >     print '%s:' % root,
  >     try:
  >         cl.reachableroots(root, [len(cl) - 1], [root])
  >         print 'uncaught error?'
  >     except TypeError as inst:
  >         print inst
  > EOF
  good heads:
  0: [0]
  1: [0]
  -1: []
  bad heads:
  2: head out of range
  10000: head out of range
  -2: head out of range
  -10000: head out of range
  None: an integer is required
  good roots:
  0: [0]
  1: [1]
  -1: [-1]
  out-of-range roots are ignored:
  2: []
  10000: []
  -2: []
  -10000: []
  bad roots:
  None: an integer is required

  $ cd ..

Test corrupted p1/p2 fields that could cause SEGV at parsers.c:

  $ mkdir invalidparent
  $ cd invalidparent

  $ hg clone --pull -q --config phases.publish=False ../a limit
  $ hg clone --pull -q --config phases.publish=False ../a segv
  $ rm -R limit/.hg/cache segv/.hg/cache

  $ python <<EOF
  > data = open("limit/.hg/store/00changelog.i", "rb").read()
  > for n, p in [('limit', '\0\0\0\x02'), ('segv', '\0\x01\0\0')]:
  >     # corrupt p1 at rev0 and p2 at rev1
  >     d = data[:24] + p + data[28:127 + 28] + p + data[127 + 32:]
  >     open(n + "/.hg/store/00changelog.i", "wb").write(d)
  > EOF

  $ hg debugindex -f1 limit/.hg/store/00changelog.i
     rev flag   offset   length     size   base   link     p1     p2       nodeid
       0 0000        0       63       62      0      0      2     -1 7c31755bf9b5
       1 0000       63       66       65      1      1      0      2 26333235a41c
  $ hg debugindex -f1 segv/.hg/store/00changelog.i
     rev flag   offset   length     size   base   link     p1     p2       nodeid
       0 0000        0       63       62      0      0  65536     -1 7c31755bf9b5
       1 0000       63       66       65      1      1      0  65536 26333235a41c

  $ cat <<EOF > test.py
  > import sys
  > from mercurial import changelog, scmutil
  > cl = changelog.changelog(scmutil.vfs(sys.argv[1]))
  > n0, n1 = cl.node(0), cl.node(1)
  > ops = [
  >     ('reachableroots',
  >      lambda: cl.index.reachableroots2(0, [1], [0], False)),
  >     ('compute_phases_map_sets', lambda: cl.computephases([[0], []])),
  >     ('index_headrevs', lambda: cl.headrevs()),
  >     ('find_gca_candidates', lambda: cl.commonancestorsheads(n0, n1)),
  >     ('find_deepest', lambda: cl.ancestor(n0, n1)),
  >     ]
  > for l, f in ops:
  >     print l + ':',
  >     try:
  >         f()
  >         print 'uncaught buffer overflow?'
  >     except ValueError, inst:
  >         print inst
  > EOF

  $ python test.py limit/.hg/store
  reachableroots: parent out of range
  compute_phases_map_sets: parent out of range
  index_headrevs: parent out of range
  find_gca_candidates: parent out of range
  find_deepest: parent out of range
  $ python test.py segv/.hg/store
  reachableroots: parent out of range
  compute_phases_map_sets: parent out of range
  index_headrevs: parent out of range
  find_gca_candidates: parent out of range
  find_deepest: parent out of range

  $ cd ..

#endif