Index: solo.c
===================================================================
--- solo.c	(revision 8764)
+++ solo.c	(working copy)
@@ -4504,7 +4504,18 @@
                 ui->hshow = 0;
             } else if (tx == ui->hx && ty == ui->hy &&
                        ui->hshow && ui->hpencil == 0) {
+#ifdef STYLUS_BASED
+                /*
+                 * Pencil-mode highlighting for non filled squares.
+                 */
+                if (state->grid[ty*cr+tx] == 0) {
+                    ui->hpencil = 1;
+                } else {
+                    ui->hshow = 0;
+                }
+#else
                 ui->hshow = 0;
+#endif
             } else {
                 ui->hx = tx;
                 ui->hy = ty;