1.10.5 Automatic zealous crop removes black colors

[Anibina]

XnView: MP 1.10.5 - 64-bit
OS: Windows 11 - 64-bit

Automatic zealous crop removes black colors.

Effect: Automatic zealous crop removes too much.

To reproduce:
1. open this image. It has a transparent background and two rectangles with a black stroke and a white fill.

source_black_stroke_white_fill.png

2. From the top left menu, choose:
Edit > Automatic crop... > Zealous

Issue:
With both horizontal and vertical choices checked:
The black strokes on all sides are erased:

zealous_crop_horiz_and_vert.png

With horizontal only, the top and bottom strokes are erased.

zealous_crop_horiz.png

With vertical only, the left and right strokes are erased.

zealous_crop_vert.png

When the drawn shapes are a black and white fill only, without a stroke.

source_black_and_white_fill_no_stroke.png

Then the black rectangle is removed.

source_black_and_white_fill_no_stroke_zealous_crop.png

Expected:
Only crop the transparency around the shapes without removing the black strokes.

The strokes remain when the fill and stroke colors are swapped.
A white stroke with a black fill.

source_inverted_stroke_and_fill_zealous_crop.png