Index: plugins/fn-math/functions.c
===================================================================
--- plugins/fn-math/functions.c	(révision 16573)
+++ plugins/fn-math/functions.c	(copie de travail)
@@ -3218,6 +3218,10 @@
 					   GNM_EXPR_EVAL_PERMIT_NON_SCALAR |
 					   GNM_EXPR_EVAL_PERMIT_EMPTY);
 
+		if (!val) {
+			size_error = TRUE;
+			break;
+		}
 		thissizex = value_area_get_width (val, ei->pos);
 		thissizey = value_area_get_height (val, ei->pos);
 
