Palette related bugs

[DOS386]

There are some palette related bugs in 1.90 beta 2, partially already in
1.82.4:

- "Edit colormap" is "grey'ed out" in some cases when it shouldn't be, re-converting image to a palettized model workarounds it

- "Autocrop" and "Canvas size" do not work correctly for palettized
images, need to convert to truecolor before and back after. Autocrop does
nothing (want to crop out black, margin is black but does not crop), adding
margin with "Canvas size" adds wrong colours for palettized images, already present in 1.82.4

V 1.90 B2

[xnview]

There are some palette related bugs in 1.90 beta 2, partially already in
1.82.4:

- "Edit colormap" is "grey'ed out" in some cases when it shouldn't be, re-converting image to a palettized model workarounds it

Do you know how to have this problem?

- "Autocrop" and "Canvas size" do not work correctly for palettized
images, need to convert to truecolor before and back after. Autocrop does
nothing (want to crop out black, margin is black but does not crop), adding
margin with "Canvas size" adds wrong colours for palettized images, already present in 1.82.4

Autocrop work only for RGB pictures. And yes, normal, the RGB color used for canvas size is not always in the colormap...

[DOS386]

I wrote:

"Edit colormap" is "grey'ed out" in some cases when it shouldn't be, re-converting image to a palettized model workarounds

xnview wrote:

Do you know how to have this problem?

Retested: There is possibly no bug, just the problem that image converts to
true colour too silently with many operations.

xnview wrote:

Autocrop work only for RGB pictures. And yes, normal, the RGB color used for canvas size is not always in the colormap...

OK, then Autocrop should either refuse ("This is a palletizzed image,
convert to TrueColour before Autocrop"), or convert and warn about
this fact. Same applies to Canvas: refuse, convert and warn, or select
new colour from existing palette.