view tests/test-parseindex.t @ 39356:c8e4eae84808

narrow: add server logic to send cg while widening without ellipsis

Before this patch, if you try to widen a narrow clone without ellipsis enabled,
it will be broken and the exchange.pull() done by tracked command to widen the
clone will be no-op because no custom logic exists for this and server sees that
we have all csets and it says `no changes found`.

The widening with ellipsis send KILL for existing changegroups and send new
changegroups because of the change in ellipsis hash, but we can prevent that in
non-ellipsis cases.

This patch adds server side logic to send the changegroups for the changesets
which are on the client again with filelogs and manifests for the new includes.
This is a very starting implementation and we send changegroups and manifests
too while we can prevent them.

Following things can definitely be improved in the logic this patch adds:

  1) Send just the filelogs and treemanifests
  2) Send the filelogs only for the additions in the include

I tried 1) here but the code is coupled tightly and the way I was able to do
that was hacking into the changegroup generation code in a very dirty way, like
adding conditionals and preventing the yield.

This patch also adds a 'widen' kwarg to prevent other commands except widening
to go through that codepath.

The test changes demonstrate that the new implementation is correct and fixes
things.

Differential Revision: https://phab.mercurial-scm.org/D4383

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 __future__ import print_function
  > from mercurial import changelog, vfs
  > 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 __enter__(self):
  >         self.real.__enter__()
  >         return self
  > 
  >     def __exit__(self, *args, **kwargs):
  >         return self.real.__exit__(*args, **kwargs)
  > 
  > def opener(*args):
  >     o = vfs.vfs(*args)
  >     def wrapper(*a, **kwargs):
  >         f = o(*a, **kwargs)
  >         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 __future__ import print_function
  > from mercurial import changelog, vfs
  > cl = changelog.changelog(vfs.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, end=' ')
  >     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, end=' ')
  >     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 [(b'limit', b'\0\0\0\x02'), (b'segv', b'\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 + b"/.hg/store/00changelog.i", "wb").write(d)
  > EOF

  $ hg -R limit debugrevlogindex -f1 -c
     rev flag     size   link     p1     p2       nodeid
       0 0000       62      0      2     -1 7c31755bf9b5
       1 0000       65      1      0      2 26333235a41c

  $ hg -R limit debugdeltachain -c
      rev  chain# chainlen     prev   delta       size    rawsize  chainsize     ratio   lindist extradist extraratio
        0       1        1       -1    base         63         62         63   1.01613        63         0    0.00000
        1       2        1       -1    base         66         65         66   1.01538        66         0    0.00000

  $ hg -R segv debugrevlogindex -f1 -c
     rev flag     size   link     p1     p2       nodeid
       0 0000       62      0  65536     -1 7c31755bf9b5
       1 0000       65      1      0  65536 26333235a41c

  $ hg -R segv debugdeltachain -c
      rev  chain# chainlen     prev   delta       size    rawsize  chainsize     ratio   lindist extradist extraratio
        0       1        1       -1    base         63         62         63   1.01613        63         0    0.00000
        1       2        1       -1    base         66         65         66   1.01538        66         0    0.00000

  $ cat <<EOF > test.py
  > from __future__ import print_function
  > import sys
  > from mercurial import changelog, vfs
  > cl = changelog.changelog(vfs.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 + ':', end=' ')
  >     try:
  >         f()
  >         print('uncaught buffer overflow?')
  >     except ValueError as 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