bug#66068: 30.0.50; xwidget-webkit-browse-url makes Emacs abort

[Stephen Berman]

I just built Emacs --with-xwidgets on a new system (glibc-2.38,
gcc-13.2.0, linux-6.5.2) on which I've installed webkitgtk-2.41.92 for
both Gtk3 and Gtk4 (libwebkit2gtk-4.1.so and libwebkitgtk-6.0.so).  When
I invoke `M-x xwidget-webkit-browse-url', enter a URL at the prompt and
press RET, Emacs aborts.  I ran under gdb and have attached a full
backtrace.

In GNU Emacs 30.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
 3.24.38, cairo version 1.17.6) of 2023-09-18 built on strobelfs2
Repository revision: b331bf6d8a21ef3ac7e70d3f4a937e4256178d55
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101008
System Description: Linux From Scratch r12.0-19

Configured using:
 'configure -C --with-xwidgets 'CFLAGS=-Og -g3'
 PKG_CONFIG_PATH=/opt/qt5/lib/pkgconfig'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBSYSTEMD LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PNG RSVG
SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS WEBP X11 XDBE XIM
XINPUT2 XPM XWIDGETS GTK3 ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

txtB4fkPz7N4R.txt
Description: gdb backtrace