Windows 7 64-bit GTX 770
Broken: 2.78 Stable (e92f235283) and 2.78 Daily (7b25ffb)
Short description of error
While trying to add poses to the Pose Library, if you are currently in tweak mode for an action strip, an empty pose will be added to the library instead of the rig's actual/current pose.
Exact steps for others to reproduce the error
Select an action strip >> Press tab (tweak action strip)
Add Pose to Pose Library >> change pose / stop tweaking and (go to a different frame)
Loading the pose will do nothing
Repeat steps, without being in tweak mode, and it will work correctly.
While setting up for this report, at one point, it still worked in tweak mode but every prior/subsequent try resulted the same.
It's reproducible, but I can't find any other cause aside from action-strip tweak.