Well it looks like the bug either still exists or this could be an entirely new one. There have been some reports of Nexus 5 owners who discovered that the “mm-qcamera-daemon” activity on their phone is using up a chunk of their phone’s battery. Google has yet to publicly comment on this, but thankfully it looks like it will be addressed with the release of Android L.
This is according to a Googler who had marked the bug as “future release” in the AOSP tracker, which means that chances are it will be addressed in the Android L update when it has been pushed out to Nexus 5 owners. According to reports, this issue is caused when the daemon enters a stuck state, in which it will consume a large number of CPU cycles thus draining the battery.
Now as pointed out by Android Police, this is an issue for the Nexus 5 phone, meaning that if you were to encounter it on another Android device, you will have to take up that issue with the OEM. In the meantime are many Nexus 5 owners encountering this issue on their phones?