#428 `\pgfkeyscurrentkey` is empty when manual says otherwise

[Evan Aad]

The first code example on p. 883 of the manual (for version 3.0.1a) lists the output

Initial definition. Re-Definition. Unknown key ''.

however the comments that accompany the code listing say the output should be

Initial definition. Re-Definition. Unknown key '/the/other key/.code'.

So it looks like the \pgfkeyscurrentkey macro expand to an empty string, when it should expand to the string /the/other key/.code.

[Evan Aad]

Stefan Pinnow, this is not just an inconsistency in the manual; it'a a software bug: \pgfkeyscurrentkey doesn't expand to what it's supposed to.