Index: xemacs-21.5.29/src/extents.c
===================================================================
--- xemacs-21.5.29.orig/src/extents.c
+++ xemacs-21.5.29/src/extents.c
@@ -3119,6 +3119,10 @@ extent_fragment_update (struct window *w
 	    
 	    gb.glyph = glyph;
 	    gb.extent = wrap_extent (e);
+	    /* not used, but necessary to avoid compiler warnings about unitiallized variables */
+	    gb.findex = 0;
+	    gb.active = 0;
+	    gb.width = 0; 
 	    Dynarr_add (ef->begin_glyphs, gb);
 	  }
 	  else if (EQ (glyph, last_glyph))
@@ -3138,6 +3142,10 @@ extent_fragment_update (struct window *w
 
 	    gb.glyph = glyph;
 	    gb.extent = wrap_extent (e);
+	    /* not used, but necessary to avoid compiler warnings about unitiallized variables */
+	    gb.findex = 0;
+	    gb.active = 0;
+	    gb.width = 0; 
 	    Dynarr_add (ef->end_glyphs, gb);
 	  }
 	  else if (EQ (glyph, last_glyph))