Shlex is only intended to work for Unix-like shells, and using it on
Windows causes problems. We now resort to simply always using the shell
on Unix-like platforms (as our command input is always a string, and not
an array). On Windows, the string input is always okay, even when not
using the shell.
This is a follow-up to a bug report by M. Kammerer on failing Windows
installs.
Previously, pressing 'cancel' in the verification window would leave a dangling scyther backend process.
Now the process gets correctly killed.
The following changes enable this:
- External processes are no longer invoked through the shell (otherwise they are subprocesses of the shell and cannot be reliably killed cross-platform).
- The 'safeCommand' procedure now has a hook for passing opened Popen objects.
- The GUI stores and kills the Popen objects on cancel or window close.
To do: an alternative interface for this in 'safeCommand' could expose a 'killMe' method through a callback; this might be cleaner in the long term.
Before, we were using both __file__ as well as sys.argv[0] to determine the base directory
for Scyther, and we were not taking symlinks into account.
By using the inspect module, we can consistently pick the current frame and derive
the file from that, then use realpath to strip symlinks.
If this variable is unset, Scyther writes into /tmp/Scyther-cache (or similar).
If this variable is set to "", caching is disabled.
Otherwise, Scyther writes into $SCYTHERCACHEDIR/Scyther-cache
Cached data is stored in:
Cache/XX/YYYYY.out (stdout)
Cache/XX/YYYYY.err (stderr)
Where XX^YYYYY is the sha256 hexdigest of the concatenation of the input spdl and
the arguments.
The script runs over all protocol files it can find, and runs it using two different
command-line parameters to scyther. If the results differ, the script reports it.
The code can use some cleanup, removing e.g. global variables, but it works.
