[gtksourceview] map: adjust size request for borders

[Christian Hergert <chergert src gnome org>]

commit bf2569d776dc6df509f64b6f65a950a1681736b4
Author: Christian Hergert <chergert redhat com>
Date:   Mon Jun 21 07:42:10 2021 -0700

    map: adjust size request for borders
    
    Borders could cause us to request more than we have, which results in
    runtime warnings.

 gtksourceview/gtksourcemap.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/gtksourceview/gtksourcemap.c b/gtksourceview/gtksourcemap.c
index 7f744ad6..1730e6d6 100644
--- a/gtksourceview/gtksourcemap.c
+++ b/gtksourceview/gtksourcemap.c
@@ -257,12 +257,14 @@ static void
 update_scrubber_position (GtkSourceMap *map)
 {
        GtkSourceMapPrivate *priv;
+       GtkStyleContext *style_context;
        GtkTextIter iter;
        GdkRectangle visible_area;
        GdkRectangle iter_area;
        GdkRectangle scrubber_area;
        GtkAllocation alloc;
        GtkAllocation view_alloc;
+       GtkBorder border;
        gint ignored;
        gint child_height;
        gint view_height;
@@ -293,8 +295,11 @@ update_scrubber_position (GtkSourceMap *map)
                                            visible_area.x, visible_area.y);
        gtk_text_view_get_iter_location (GTK_TEXT_VIEW (map), &iter, &iter_area);
 
+       style_context = gtk_widget_get_style_context (GTK_WIDGET (map));
+       gtk_style_context_get_border (style_context, &border);
+
        scrubber_area.x = 0;
-       scrubber_area.width = alloc.width;
+       scrubber_area.width = alloc.width - border.left - border.right;
        scrubber_area.y = iter_area.y;
        scrubber_area.height = ((gdouble)view_alloc.height /
                                (gdouble)view_height *