bug#38109: 27.0.50; xpm image scaling doesn't work

[Stephen Berman]

On Thu, 07 Nov 2019 22:11:14 +0100 Unknown <unknown@unknown.invalid> wrote:

> I *think* scaling of xpm images used to work (maybe back when
> ImageMagick did the scaling?) - but it doesn't now, e.g. if you go:
>
>   (insert-image (create-image
> "/usr/src/emacs/etc/images/smilies/medium/wry.xpm" nil nil :scale 20.0))
>
> a tiny 16x16 image is inserted. The expected result was a huge 320x320
> image.
[...]
> Configured features:
> XPM JPEG TIFF GIF PNG RSVG SOUND GPM DBUS GSETTINGS GLIB NOTIFY INOTIFY
> ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF XFT ZLIB
> TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM THREADS LIBSYSTEMD PDUMPER LCMS2
> GMP

On Thu, 07 Nov 2019 22:30:57 +0100 Unknown <unknown@unknown.invalid> wrote:

> I just updated my Emacs build to master HEAD now (previously was built
> in mid-October), and the results are consitent no scaling for XPM, GIF
> and PNG now [...]

Cf. NEWS:

 ** Emacs now supports resizing and rotating images without ImageMagick.
 All modern systems support this feature.  (On GNU and Unix systems,
 Cairo drawing or the XRender extension to X11 is required for this to
 be available; the configure script will test for it and, if found,
 enable scaling.)

I'm not sure about XRender; I think my X has it, but I only get scaling
(also of XPM and PNG images) with the Cairo build.

Steve Berman