Bug#1010288: 'Rotate' rotates entire image regardless of layer or selection.

[Ray Dillinger]

package: gimp
Version: 2.10.30-1+b1
Severity: Normal

The 'rotate' tool in GIMP is now ignoring selection area and layer
restrictions, making it impossible to rotate any part of the image
relative to other parts.

Note, there is a workaround.  Cut to the last paragraph if that's all
you're interested in.

I opened gimp with the intention of creating printable specialized graph
paper with a triangular grid.  So I made a transparent layer and used
'snap to grid' to precisely draw and paste a set of exactly parallel lines.

I intended to paste two more copies of this set of lines, at 60- and
120-degree rotations, to make the triangular grid. So I did select all,
copy, paste, grab the rotation tool to rotate the pasted layer.

When I attempted to use it, it rotated the entire image, including the
layer boundaries of the base layer and the horizontal-lines layer. So I
control-Z undid that, made sure I had selected the pasted layer, and
tried again.  Same result. 

I supposed maybe rotate had been changed and no longer worked on
"pasted" layers for some reason, so I transformed the pasted layer into
a normal layer.  I made sure I had selected that layer and tried again. 
Same result.

I thought maybe they changed rotate so it only works on explicit
selected areas, so I made sure to select all, on that layer, and tried
again.  Same result.

Just to see whether it mattered how the selection was made, I selected
"most" of the area with the wrecked-angle select tool leaving about 5
pixels around the edges unselected, and tried again.  Same result.

At this point I concluded that it is not possible to rotate any part of
the image relative to any other in normal use.

As a workaround I rotated the entire image, exported a .png file, then
rotated it again and exported another .png file.  Then I opened those
images as separate buffers, and cut and pasted from them into my main
buffer.  Note, when doing this make sure the alpha channel for
transparency is preserved in the export options.

Hope this helps!

Bear