GUACAMOLE-2234: Fix race condition in non-opaque layer clearing across display worker threads.

[sschiffli]

Adding path_lock to guac_display_layer, acquired around the rect+cfill pair in guac_display_layer_clear_non_opaque(). The lock is per-layer, so workers on different layers are unaffected.

[necouchman]

@sschiffli The build seems to be failing; however, it doesn't look like it's necessarily related to your changes, so many just a transient issue? I'll merge once I can figure out why that's failing and how to get through that.

[necouchman]

-Sigh- We have a bit of a problem, here...

#ifndef FREERDP_VERSION_H
#define FREERDP_VERSION_H

#define FREERDP_VERSION_MAJOR 2
#define FREERDP_VERSION_MINOR 11
#define FREERDP_VERSION_REVISION 8
#define FREERDP_VERSION_SUFFIX "dev"
#define FREERDP_API_VERSION "2"
#define FREERDP_VERSION "2.11.8"
#define FREERDP_VERSION_FULL "2.11.8-dev"
#define GIT_REVISION "2.11.8"

#endif /* FREERDP_VERSION_H */

Apparently when the FreeRDP team released the most recent version of FreeRDP, they left the -dev on the end of the version:

https://github.com/FreeRDP/FreeRDP/blob/9b678b6d5a40ce01607d8c3b1b1416437c8416c4/CMakeLists.txt#L88

I've posted a discussion question to ask if there's a reason they didn't drop it.

@mike-jumper Thoughts on the best way to handle this one?

[mike-jumper]

Is there a macro in the FreeRDP version information header that includes the git hash? We could build in an exception for this specific version.

Otherwise, I'd say we could turn the dev version check into a warning and just make sure that the warning shows up at the end of the configure summary (so users will see it).

[necouchman]

Is there a macro in the FreeRDP version information header that includes the git hash? We could build in an exception for this specific version.

I do not see one, no.

Otherwise, I'd say we could turn the dev version check into a warning and just make sure that the warning shows up at the end of the configure summary (so users will see it).

Okay, may just change the AC_MSG_ERROR to AC_MSG_WARN. I'll put in a Jira ticket and pull request for it.

[necouchman]

@sschiffli If you can rebase on top of the current staging/1.6.1 branch, this will hopefully fix the build check and we can get this merged.

[sschiffli]

Thanks for the quick build fix, rebase done!