bug#59944: Transparency with alpha-background doesn't work well with PNG images on Emacs 29.0.60

bug#59944: Transparency with alpha-background doesn't work well with PNG images on Emacs 29.0.60

[Satya Prakash Dahal]

[-- Attachment #1.1: Type: text/plain, Size: 389 bytes --]

PNG images with a transparent background are not transparent.
Look at the image emacs_png_bug.png on the attachment.
This is my first bug report. If I am missing something please let me know.
Below are the commands i used to compile the emacs.

git clone https://github.com/emacs-mirror/emacs.git
*cd emacs*
*./autogen.sh*
*./configure*

*./configure --with-mailutils && makemake install*

[-- Attachment #1.2: Type: text/html, Size: 1068 bytes --]

[-- Attachment #2: emacs_png_bug.png --]
[-- Type: image/png, Size: 973435 bytes --]

bug#59944: Transparency with alpha-background doesn't work well with PNG images on Emacs 29.0.60

[Po Lu via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Satya Prakash Dahal <be2020se701@gces.edu.np> writes:

> PNG images with a transparent background are not transparent. 
> Look at the image emacs_png_bug.png on the attachment.
> This is my first bug report. If I am missing something please let me know.
> Below are the commands i used to compile the emacs.
>
> git clone https://github.com/emacs-mirror/emacs.git
> cd emacs
> ./autogen.sh
> ./configure
> ./configure --with-mailutils && make
> make install

Well, does anyone want to fix this?

It should be "as simple" as making libpng use the same code in
x_query_frame_color to allocate transparent colors.  But I have no idea
how to make libpng do that.

In the meantime, you can use XPM images for that icon instead, which are
free from this problem.