[gtksourceview/wip/chergert/vim] fix the enter motion a bit more

[Christian Hergert <chergert src gnome org>]

commit 77997878a266beb64f37628939edb66142fe997a
Author: Christian Hergert <chergert redhat com>
Date:   Sun Oct 24 09:46:50 2021 -0700

    fix the enter motion a bit more

 gtksourceview/vim/gtk-source-vim-motion.c | 47 ++++++++++++++++++++-----------
 1 file changed, 30 insertions(+), 17 deletions(-)
---
diff --git a/gtksourceview/vim/gtk-source-vim-motion.c b/gtksourceview/vim/gtk-source-vim-motion.c
index 6e704876..130afbbc 100644
--- a/gtksourceview/vim/gtk-source-vim-motion.c
+++ b/gtksourceview/vim/gtk-source-vim-motion.c
@@ -467,32 +467,45 @@ motion_next_line (GtkTextIter        *iter,
 {
        GtkTextIter before = *iter;
 
-       gtk_text_buffer_get_iter_at_line (gtk_text_iter_get_buffer (iter),
-                                         iter,
-                                         gtk_text_iter_get_line (iter) + 1);
+       if (gtk_text_iter_forward_to_line_end (iter))
+               gtk_text_iter_forward_char (iter);
+
+       if (gtk_text_iter_is_end (iter))
+               gtk_text_iter_backward_char (iter);
+
+       return !gtk_text_iter_equal (&before, iter);
+}
+
+static gboolean
+motion_next_line_first_char (GtkTextIter        *iter,
+                             GtkSourceVimMotion *state)
+{
+       GtkTextIter before = *iter;
+
+       if (!gtk_text_iter_ends_line (iter))
+               gtk_text_iter_forward_to_line_end (iter);
+
+       gtk_text_iter_forward_char (iter);
 
+       /* If we are on the same line, then we must be at the end of
+        * the buffer. Just move to one character before EOB.
+        */
        if (gtk_text_iter_get_line (&before) == gtk_text_iter_get_line (iter))
        {
-               /* must be at end of file now. move to end of buffer
-                * but do not go past the last character.
-                */
                gtk_text_iter_forward_to_line_end (iter);
                if (!gtk_text_iter_starts_line (iter))
                        gtk_text_iter_backward_char (iter);
-               return gtk_text_iter_equal (iter, &before);
+               return !gtk_text_iter_equal (&before, iter);
        }
 
-       motion_line_first_char (iter, state);
-
-       return !gtk_text_iter_equal (iter, &before);
-}
+       while (!gtk_text_iter_ends_line (iter) &&
+              g_unichar_isspace (gtk_text_iter_get_char (iter)))
+       {
+               if (!gtk_text_iter_forward_char (iter))
+                       break;
+       }
 
-static gboolean
-motion_next_line_first_char (GtkTextIter        *iter,
-                             GtkSourceVimMotion *state)
-{
-       return motion_next_line (iter, state) &&
-              motion_line_first_char (iter, state);
+       return !gtk_text_iter_equal (&before, iter);
 }
 
 static gboolean