; * etc/PROBLEMS: Add an entry about WebKitGTK (bug#66068).

diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index b4df40f5d8e3be2bbbb35eab5d019d5b2d78e6e4..642c3d0169e527c36cbe719abae6f43d62bc6e64 100644 (file)
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -178,6 +178,32 @@ The relevant bug report is here:
 A workaround is to set XLIB_SKIP_ARGB_VISUALS=1 in the environment
 before starting Emacs, or run Emacs as root.
 
+** Emacs built with xwidgets aborts when displaying WebKit xwidgets
+
+This happens, for example, when 'M-x xwidget-webkit-browse-url'
+prompts for a URL and you type the URL at the prompt.
+
+The error message might look like this:
+
+  X protocol error: GLXBadWindow on protocol request 151
+  Serial no: 4286
+  Failing resource ID (if any): 0x3c001c5
+  Minor code: 32
+
+This happens because starting from version 2.42.1, the WebKitGTK
+developers discontinued support for off-screen windows, by presuming
+that every window holding a WebView widget is an X server window
+eligible for an OpenGL context.  Emacs requires placing these widgets
+within offscreen windows managed by GTK, for each xwidget might be
+displayed in multiple distinct windows, and its contents must be
+captured and reproduced within all of them if that be the case.
+
+To put this another way, WebKitGTK doesn't support displaying a single
+widget more than once anymore.
+
+A possible workaround is to make sure xwidgets are not shown in more
+than one window.
+
 ** Emacs crashes with SIGTRAP when trying to start a WebKit xwidget.
 
 This could happen if the version of WebKitGTK installed on your system