I think this is "normal" behavior of the (flawed) clipping code of the Qwt library. If you plot from 0.001 to 1.1 and vary the windows size, you will see that the last grid line is there if the window is big enough. This is basically a rounding error due to Qwt's limitation to integer coordinates.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
screen shot
Confirmed. Same happens for x axis.
I think this is "normal" behavior of the (flawed) clipping code of the Qwt library. If you plot from 0.001 to 1.1 and vary the windows size, you will see that the last grid line is there if the window is big enough. This is basically a rounding error due to Qwt's limitation to integer coordinates.
Hmm - I have reproduced this, but unlike Tilman, resizing the window never regenerates the last grid line.
Still present in top of tree (1.23)