writes a chunk of compressed data, closes it, writes another chunk, and
reads the contents back to verify that they are the same.

allow using the 'a' flag as a mode for opening a GzipFile.  gzip
files, surprisingly enough, can be concatenated and then decompressed;
the effect is to concatenate the two chunks of data.

If we support it on writing, it should also be supported on reading.
This *wasn't* trivial, and required rearranging the code in the
reading path, particularly the _read() method.

Raise IOError instead of RuntimeError in two cases, 'Not a gzipped file'
and 'Unknown compression method'

Lockwood).

is not an empty string, this means that you have arrived at the
end of the stream of compressed data, and the contents of .unused_data are
whatever follows the compressed stream.

argument.  This closes TODO item 2.19.

This change was made long ago but the documentation was never updated.

style sheet.

Small nits.

requested Python tools/examples.

Unfortunately his code breaks wcgui.py in a way that's not easy
to fix.  I expect that this is a temporary situation --
eventually Sam's changes will be merged back in.
(The changes add a -t option to specify exceptions to the -x
option, and explicit checking for #foo style fragment ids.)

Fix comments about zlib version and URL.

data struct before calling gethostby{name,addr}_r(); (2) ignore the
3/5/6 args determinations made by the configure script and switch on
platform identifiers instead:

AIX, OSF have 3 args
Sun, SGI have 5 args
Linux has 6 args

On all other platforms, undef HAVE_GETHOSTBYNAME_R altogether.

Chris Lawrence sent me a broken version; this one is a tad simpler and
more conforming to the standard.

This is in response to a comment from Wes Rishel <wes@rishel.com>.

with egcs (after setting EXE=.exe).  Patch by Norman Vine.

ProcessHierarchy's changes to support reading from a remote URL in
ProcessDatabase).

As requested by Bill Janssen.

donated by David Arnold.

- Use HAVE_GETHOSTBYNAME_R_6_ARG instead of testing for Linux and
glibc2.

- If gethostbyname takes 3 args, undefine HAVE_GETHOSTBYNAME_R --
don't know what code should be used.

- New symbol USE_GETHOSTBYNAME_LOCK defined iff the lock should be used.

- Modify the gethostbyaddr() code to also hold on to the lock until
after it is safe to release, overlapping with the Python lock.

(Note: I think that it could in theory be possible that Python code
executed while gethostbyname_lock is held could attempt to reacquire
the lock -- e.g. in a signal handler or destructor.  I will simply say
"don't do that then.")

Here's a patch to fix the race condition, which wasn't fixed by Rob's
patch.  It holds the gethostbyname lock until the results are copied out,
which means that this lock and the Python global lock are held at the same
time.  This shouldn't be a problem as long as the gethostbyname lock is
always acquired when the global lock is not held.

    the end of loop was incorrect, and failed when the flushmode != Z_FINISH.
    Logic cleaned up and commented.

    different flush values Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FULL_FLUSH.

a much less formalistic way.  Just keeping this around for possible
future reference.

a block cannot be freed, add its free items back to the free list.
This is necessary to avoid leaking when Python is reinitialized later.