[gtk/wip/chergert/fix-4134] textview: fix yoffset position when top_margin is set

[Christian Hergert <chergert src gnome org>]

commit 908b1e5e1214afc01440bc07a8d937222f411f38
Author: Christian Hergert <chergert redhat com>
Date:   Thu Jul 29 16:45:04 2021 -0700

    textview: fix yoffset position when top_margin is set
    
    This doesn't need to be included in the calculation or it will cause the
    yoffset to continually shift while the window is resized.
    
    Fixes #4134

 gtk/gtktextview.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtk/gtktextview.c b/gtk/gtktextview.c
index 71c48ab844..3f5836f0aa 100644
--- a/gtk/gtktextview.c
+++ b/gtk/gtktextview.c
@@ -4892,7 +4892,7 @@ changed_handler (GtkTextLayout     *layout,
 
       gtk_text_layout_get_line_yrange (layout, &first, &new_first_para_top, NULL);
 
-      old_first_para_top = priv->yoffset - priv->first_para_pixels + priv->top_margin;
+      old_first_para_top = priv->yoffset - priv->first_para_pixels;
 
       if (new_first_para_top != old_first_para_top)
         {