In windows, without temp path set, the 'save buffers' render option crashes.
I've coded a blenlib BLI_is_writable(char *filename) to check for such
cases. This is not much needed in Blender, since the open() command is
checked for. However, file saving happens deep inside the C++ exr lib, and
it throws an exception crash when a file cannot be written.
He even made a nice doc in wiki:
http://wiki.blender.org/bin/view.pl/Blenderdev/Blendgz
Usage: set the option "Compress File" in the main "File" pulldown menu.
This setting is a user-def, meaning it is not changed on reading files.
If you want it default, save it with CTRL+U.
The longest debate went over the file naming convention. Shaul started
with .blend.gz files, which gave issues in Blender because of the code
hanging out everywhere that detects blender files, and that appends the
.blend extension if needed.
Daniel Dunbar proposed to just save it as .blend, and not bother users
with such details. This is indeed the most elegant solution, with as
only drawback that old Blender executables cannot read it.
This drawback isn't very relevant at the moment, since we're heading
towards a release that isn't upward compatible anyway... the recode
going on on Meshes, Modfiers, Armatures, Poses, Actions, NLA already
have upward compatibility issues.
We might check - during the next month(s) - on a builtin system to
warn users in the future when we change things that make a file risky
to read in an older release.
When the render output directory doesn't exist (on windows) the BLI_recurdir_fileops() function
tries to create a directory with no name. Added check if a name is specified..
