HP50 : indefinite integral of '0^x' gives '?' and 0 for '0*x'

[rawi]

Some additional information:
Casio CP 400: Integral from 1 to 2 of 0^x: Undefined.

HP 15C:
If you integrate the follwing program:

LBL A
0
X<>Y
Y^X
g RTN

from 0 to 1 or from 1 to 2 the result is always 0.

As well the TI 89 Titanium and the TI nsprire get the integral from 0 to 1 right with the result 0.