bug#22916: 25.0.92; eww completely hangs Emacs on "invalid" png image

[Eli Zaretskii]

> From: Elric Milon <whirm@gmx.com>
> Date: Fri, 27 Jan 2017 12:16:56 +0100
> Cc: 22916@debbugs.gnu.org
> 
> I just tried building current master with:
> 
> 
>       ./autogen.sh
> 
>       ./configure --prefix $(readlink -fe $PWD/../inst) \
>           --enable-link-time-optimization \
>           --without-pop \
>           --with-x-toolkit=gtk3 \
>           --without-xaw3d \
>           --without-selinux \
>           --with-file-notification=yes \
>           --with-modules \
>           --with-cairo \
>           --without-pop \
>           --with-x
> 
>       make -j4
> 
> But it's unusable for me (The whole Emacs frame blinks on and off with the 
> cursor).

Please try disabling the double-buffering feature, like this:

  M-: (modify-frame-parameters nil '((inhibit-double-buffering . t))) RET

Alternatively, edit src/config.h to delete this line:

  #define HAVE_XDBE 1

and then rebuild Emacs.  Please tell if the problem goes away when you
try that.