view tests/test-parseindex.t @ 23923:ab6fd3205dad stable

largefiles: fix commit of a directory with no largefile changes (issue4330)

When a directory is named in the commit file list, the previous behavior was to
walk the list, and if no normal files in the directory were also named, add the
corresponding standin for each largefile in that directory.  The directory is
then dropped from the list, so that committing a directory with no normal file
changes works.  It then added the corresponding standin directory for the first
largefile seen, by prefixing it with '.hglf/'.

The latter is unnecessary since each affected largefile is explicitly referenced
by its standin in the list.  It also caused an abort if there were no changed
largefiles in the directory, because none of its standins changed:

    abort: .hglf/foo/bar: no match under directory!

This list of files is used to tweak a matcher in lfutil.updatestandinsbymatch(),
which is what is passed to commit().

The status() call that is ultimately done in the commit code with this matcher
seems to have some OS specific differences.  It is not necessary to append '.'
for Windows to run the largefiles tests cleanly.  But if '.' is not added to the
list, the match function isn't called on Linux, so status() would miss any
normal files that were also in a named directory.  The commit then proceeds
without those normal files, or says "nothing changed" if there were no changed
largefiles in the directory.  This is not filesystem specific, as VFAT on Linux
had the same behavior as when run on ext4.  It is also not an issue with
lfilesrepo.status(), since that only calls the overridden implementation when
paths are passed to commit.  I dont have access to an OS X machine ATM to test
there.

Maybe there's a better way to do this.  But since the standin directory for the
first largefile was previously being added, and that caused the same walk in
status(), there's no preformance change to this.  There is no danger of
erroneously committing files in '.', because the original match function is
called, and if it fails, the lfutil.updatestandinsbymatch() tweaked matcher only
indicates a match if the file is in the list of standins- and '.' never is.  The
added tests confirm this.

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 ..