Fix contributed upstream here:
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=42694.

Index: emacs-26.3/src/xfns.c
===================================================================
--- emacs-26.3.orig/src/xfns.c
+++ emacs-26.3/src/xfns.c
@@ -2628,6 +2628,8 @@ xic_free_xfontset (struct frame *f)
 static XIMStyle
 best_xim_style (XIMStyles *xim)
 {
+  if (xim == NULL) goto out;
+
   int i, j;
   int nr_supported = ARRAYELTS (supported_xim_styles);

@@ -2636,6 +2638,7 @@ best_xim_style (XIMStyles *xim)
       if (supported_xim_styles[i] == xim->supported_styles[j])
	return supported_xim_styles[i];

+ out:
   /* Return the default style.  */
   return XIMPreeditNothing | XIMStatusNothing;
 }
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<tr><td><span title='2024-04-16 22:20:40 +0100'>2024-04-16</span></td><td><a href='/guix/commit/gnu/packages/markup.scm?id=6a6dde505888bb1aff84bb02480f94312ac2989f'>gnu: Add latexml.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/markup.scm (latexml): New variable.

Reviewed-by: Steve George &lt;steve@futurile.net&gt;

Change-Id: If7199a8b74b990ad29718adcb905a5ed31882cf5
Signed-off-by: Christopher Baines &lt;mail@cbaines.net&gt;
</span></span></td><td>Nicolas Graves via Guix-patches via</td></tr>
<tr><td><span title='2024-03-31 07:37:17 -0300'>2024-03-31</span></td><td><a href='/guix/commit/gnu/packages/markup.scm?id=43ed834127efb86282856e0e3940735de94bee39'>gnu: python-mistletoe: Update to 1.3.0.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/markup.scm (python-mistletoe): Update to 1.3.0.
[build-system]: Use pyproject-build-system.
[arguments]: Do not override the check phase, skip one test in #:test-flags.
[native-inputs]: Add python-parameterized, python-pytest.

Change-Id: If25e3cbe19d8936d150c830f1b8f4ce8f8cb5692
</span></span></td><td>Vinicius Monego</td></tr>