view tests/test-parseindex.t @ 27279:40eb385f798f

tests: add test for Python 3 compatibility

Python 3 is inevitable. There have been incremental movements towards
converting the code base to be Python 3 compatible. Unfortunately, we
don't have any tests that look for Python 3 compatibility. This patch
changes that.

We introduce a check-py3-compat.py script whose role is to verify
Python 3 compatibility of the files passed in. We add a test that
calls this script with all .py files from the source checkout.

The script currently only verifies that absolute_import and
print_function are used. These are the low hanging fruits for Python
compatbility. Over time, we can include more checks, including
verifying we're able to load each Python file with Python 3. You
have to start somewhere.

Accepting this patch means that all new .py files must have
absolute_import and print_function (if "print" is used) to avoid
a new warning about Python 3 incompatibility. We've already
converted several files to use absolute_import and print_function
is in the same boat, so I don't think this is such a radical
proposition.

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