On Fri, Mar 2, 2018 at 9:06 AM, Eli Zaretskii <eliz@gnu.org> wrote:

> > From: Alex Schröder <kensanata@gmail.com>
> > On Thu, Mar 1, 2018 at 7:29 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> >  > From: kensanata@gmail.com
> >  > c:/Portable Programs/emacs-26.0.91-x86_64/bin $ ls lib* | grep "png"
> >  > libpng-config
> >  > libpng16-16.dll
> >  > libpng16-config
> >
> >  Where did you get those PNG DLLs?
> >
> > These three files are in emacs-26.0.91-x86_64.zip which I got from
> > https://alpha.gnu.org/gnu/emacs/pretest/windows/
>
> How do you invoke Emacs from that installation?
>

From a shortcut in my startmenu.

Target: "C:\Portable Programs\emacs-26.0.91-x86_64\bin\runemacs.exe"
Start in: %HOMEPATH%

%HOMEPATH% is set to \Users\asc


> Are there any other versions of libpng16-16.dll on that system?
>

I ran the following:
$ find.exe / -name libpng16-16.dll
/cygdrive/c/Portable Programs/emacs-26.0.91-x86_64/bin/libpng16-16.dll
/cygdrive/c/Portable Programs/inkscape/libpng16-16.dll
/cygdrive/c/Program Files/emacs-25.1-x86_64-w64-mingw32/bin/libpng16-16.dll

I found the old C:\Program Files\emacs-25.1-x86_64-w64-mingw32\bin on my
path, removed it and restarted Emacs, verified that it was not listed in
(getenv "PATH"), but no luck. I still cannot display PNG images.


> Does pngfix.exe work (it should be in the same directory as
> libpng16-16.dll)?
>

Yes it does.

$ ./pngfix ../lib/python2.7/idlelib/Icons/idle_16.png
IDAT OK  maximum 12 12 1070 2064 ../lib/python2.7/idlelib/Icons/idle_16.png

And finally, what is the value of libpng-version in your Emacs?
>

libpng-version
10634

Cheers
Alex