"fc palette frac" does not always work for objects

[Peter J. <pet...@gm...>]

Dear gnuplot developers,

consider the following commands:

set obj 1 rect from 1,1 to 2,2 fc palette frac 0.5
plot x

The documentation says that the fillcolor part of the set object command
accepts a generic colorspec directive, which in turn should allow a "fc
palette frac" declaration.
Given the default palette I'd expect the above commands to produce a red
rectangle on the plot, however, it comes out black.

However, if I change the plot command to

plot x lc palette frac 0.1

The rectangle suddenly gets the expected color. I also get a color bar next
to the plot.

All of this suggests that in the first example some of the palette-related
data structures are not initialized correctly, while in the second example
they are, only because the palette is used with the function plot as well,
and that plot triggers the necessary initialization sequence.

Peter Juhasz