bug#68452: w32-use-native-image-API makes weird behavior

[Jinsong Zhao <jszhao@yeah.net>]

On 2024/1/15 21:08, Eli Zaretskii wrote:
>> Date: Mon, 15 Jan 2024 15:48:55 +0800
>> Cc: 68452@debbugs.gnu.org
>> From: Jinsong Zhao <jszhao@yeah.net>
>>
>>>> The PNG image is created on the fly by imaxima, a front end for Maxima.
>>>> I think it's a normal PNG image file, actually converted from a ps file
>>>> by ghostscript. I also tried to use JPEG, it's the same.
>>> Well, we cannot do anything with this bug report unless we have an
>>> example of an image to work with.  So please find a way to ask imaxima
>>> to save the image on a file, and then send it.
>> I could provide the PNG files, please see the attachments.
>>
>> File "1" and "2" are PNG files that were displayed in Emacs.
>>
>> File "11.png" and "33.png" are the screenshots with
>> w32-use-native-image-API set to nil after the first and second input.
>>
>> File "22.png" and "44.png" are the screenshots with
>> w32-use-native-image-API set to non-nil after the first and second input.
>>
>> I don't know if I am clear.
> Thanks.  I have no problems displaying the 2 PNG files with
> w32-use-native-image-API set to a non-nil value.  So I don't know why
> this doesn't work for you.  Are you able to display the files you sent
> in your Emacs with w32-use-native-image-API set to its default non-nil
> value?
My problem is not that I can't display images, but that the same action 
doesn't work the same way with either setting.

When w32-use-native-image-API is nil, image "1" can be displayed as soon 
as the Enter key is pressed (before "(%2)" appears, see 11.png). 
However, if w32-use-native-image-API is t, image 1 will not be 
displayed, just an empty box (see 22.png).

Now we enter another expression. If w32-use-native-image-API is nil, 
image "2" can be displayed immediately after pressing enter, and it will 
not affect the display of the previous image "1", see 33.png. If 
w32-use-native-image-API is t, instead of displaying an empty box, image 
"2" is not displayed, but the first empty box is replaced by image "1", 
see 44.png.

Best wishes,

Jinsong