https://bugs.gentoo.org/983119
Patch backported from upstream

commit f2c490cc233d2d55cd7c1eade9431d9711de375d
Author: Tim Hentenaar <tim@hentenaar.com>
Date:   Mon, 4 May 2026 07:29:32 +0000

    XmString: DrawLine: If there's only a single segment, don't deref
    
--- motif-2.5.2/lib/Xm/XmString.c
+++ motif-2.5.2/lib/Xm/XmString.c
@@ -3737,7 +3737,9 @@
     Boolean             set_direction = False;
     XmDirection         lay_dir = prim_dir; /* layout direction of this line */
 
-    seg = _XmEntrySegmentGet(line)[seg_index];
+    if (_XmEntryMultiple(line))
+        seg = _XmEntrySegment(line)[seg_index];
+    else seg = (_XmStringNREntry)line;
 
     if (_XmEntryType(seg) != XmSTRING_ENTRY_OPTIMIZED) {
       lay_dir = _XmEntryLayoutGet(seg, prim_dir);