[gtksourceview] map: fix a critical for negative size allocation

[Christian Hergert <chergert src gnome org>]

commit 3eead2806256f502126168c8bab9baf149a4753b
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jun 18 20:47:04 2021 -0700

    map: fix a critical for negative size allocation

 gtksourceview/gtksourcemap.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)
---
diff --git a/gtksourceview/gtksourcemap.c b/gtksourceview/gtksourcemap.c
index 96dc4246..9d71b1a5 100644
--- a/gtksourceview/gtksourcemap.c
+++ b/gtksourceview/gtksourcemap.c
@@ -300,11 +300,7 @@ update_scrubber_position (GtkSourceMap *map)
                                (gdouble)view_height *
                                (gdouble)child_height) +
                               iter_area.height;
-
-       if (scrubber_area.height > alloc.height)
-       {
-               scrubber_area.height = alloc.height;
-       }
+       scrubber_area.height = CLAMP (scrubber_area.height, 1, alloc.height);
 
        if (memcmp (&scrubber_area, &priv->scrubber_area, sizeof scrubber_area) != 0)
        {