Add support for BCE (background colour erase). This makes various escape

sequences (notable EL and ED but also IL, DL, ICH, DCH) create blank
cells using the current background colour rather than the default
colour.

On modern systems BCE doesn't really have many benefits, but most other
terminals now support it, some (lazy) applications rely on it, and it is
not hard to include now that we have pane background colours anyway.

Mostly written by Sean Haugh.

1 files changed, 35 insertions, 29 deletions

diff --git a/tmux.h b/tmux.h
index a33eec29..2a271ec5 100644
--- a/tmux.h
+++ b/tmux.h
@@ -602,6 +602,7 @@ struct grid_cell_entry {
 
 /* Grid line. */
 struct grid_line {
+	u_int			 cellused;
 	u_int			 cellsize;
 	struct grid_cell_entry	*celldata;
 
@@ -710,7 +711,7 @@ struct screen {
 	char			*ccolour;	/* cursor colour string */
 
 	u_int			 rupper;	/* scroll region top */
-	u_int		 	 rlower;	/* scroll region bottom */
+	u_int			 rlower;	/* scroll region bottom */
 
 	int			 mode;
 
@@ -1144,6 +1145,9 @@ struct tty_ctx {
 	u_int		 xoff;
 	u_int		 yoff;
 
+	/* The background colour used for clearing (erasing). */
+	u_int		 bg;
+
 	/* Saved last cell on line. */
 	struct grid_cell last_cell;
 };
@@ -1187,7 +1191,7 @@ struct client {
 	struct event	 repeat_timer;
 
 	struct event	 click_timer;
-	u_int            click_button;
+	u_int		 click_button;
 
 	struct event	 status_timer;
 	struct screen	 status;
@@ -1271,10 +1275,10 @@ struct cmd_find_state {
 	int			 flags;
 	struct cmd_find_state	*current;
 
-	struct session          *s;
-	struct winlink          *wl;
+	struct session		*s;
+	struct winlink		*wl;
 	struct window		*w;
-	struct window_pane      *wp;
+	struct window_pane	*wp;
 	int			 idx;
 };
 
@@ -1544,7 +1548,7 @@ void		 format_defaults_paste_buffer(struct format_tree *,
 
 /* hooks.c */
 struct hook;
-struct hooks 	*hooks_get(struct session *);
+struct hooks	*hooks_get(struct session *);
 struct hooks	*hooks_create(struct hooks *);
 void		 hooks_free(struct hooks *);
 struct hook	*hooks_first(struct hooks *);
@@ -1925,17 +1929,17 @@ int	 grid_cells_equal(const struct grid_cell *, const struct grid_cell *);
 struct grid *grid_create(u_int, u_int, u_int);
 void	 grid_destroy(struct grid *);
 int	 grid_compare(struct grid *, struct grid *);
-void	 grid_collect_history(struct grid *);
-void	 grid_scroll_history(struct grid *);
+void	 grid_collect_history(struct grid *, u_int);
+void	 grid_scroll_history(struct grid *, u_int);
 void	 grid_scroll_history_region(struct grid *, u_int, u_int);
 void	 grid_clear_history(struct grid *);
 const struct grid_line *grid_peek_line(struct grid *, u_int);
 void	 grid_get_cell(struct grid *, u_int, u_int, struct grid_cell *);
 void	 grid_set_cell(struct grid *, u_int, u_int, const struct grid_cell *);
-void	 grid_clear(struct grid *, u_int, u_int, u_int, u_int);
-void	 grid_clear_lines(struct grid *, u_int, u_int);
-void	 grid_move_lines(struct grid *, u_int, u_int, u_int);
-void	 grid_move_cells(struct grid *, u_int, u_int, u_int, u_int);
+void	 grid_clear(struct grid *, u_int, u_int, u_int, u_int, u_int);
+void	 grid_clear_lines(struct grid *, u_int, u_int, u_int);
+void	 grid_move_lines(struct grid *, u_int, u_int, u_int, u_int);
+void	 grid_move_cells(struct grid *, u_int, u_int, u_int, u_int, u_int);
 char	*grid_string_cells(struct grid *, u_int, u_int, u_int,
 	     struct grid_cell **, int, int, int);
 void	 grid_duplicate_lines(struct grid *, u_int, struct grid *, u_int,
@@ -1946,16 +1950,18 @@ u_int	 grid_reflow(struct grid *, struct grid *, u_int);
 void	 grid_view_get_cell(struct grid *, u_int, u_int, struct grid_cell *);
 void	 grid_view_set_cell(struct grid *, u_int, u_int,
 	     const struct grid_cell *);
-void	 grid_view_clear_history(struct grid *);
-void	 grid_view_clear(struct grid *, u_int, u_int, u_int, u_int);
+void	 grid_view_clear_history(struct grid *, u_int);
+void	 grid_view_clear(struct grid *, u_int, u_int, u_int, u_int, u_int);
 void	 grid_view_scroll_region_up(struct grid *, u_int, u_int);
 void	 grid_view_scroll_region_down(struct grid *, u_int, u_int);
-void	 grid_view_insert_lines(struct grid *, u_int, u_int);
-void	 grid_view_insert_lines_region(struct grid *, u_int, u_int, u_int);
-void	 grid_view_delete_lines(struct grid *, u_int, u_int);
-void	 grid_view_delete_lines_region(struct grid *, u_int, u_int, u_int);
-void	 grid_view_insert_cells(struct grid *, u_int, u_int, u_int);
-void	 grid_view_delete_cells(struct grid *, u_int, u_int, u_int);
+void	 grid_view_insert_lines(struct grid *, u_int, u_int, u_int);
+void	 grid_view_insert_lines_region(struct grid *, u_int, u_int, u_int,
+	u_int);
+void	 grid_view_delete_lines(struct grid *, u_int, u_int, u_int);
+void	 grid_view_delete_lines_region(struct grid *, u_int, u_int, u_int,
+	u_int);
+void	 grid_view_insert_cells(struct grid *, u_int, u_int, u_int, u_int);
+void	 grid_view_delete_cells(struct grid *, u_int, u_int, u_int, u_int);
 char	*grid_view_string_cells(struct grid *, u_int, u_int, u_int);
 
 /* screen-write.c */
@@ -1985,22 +1991,22 @@ void	 screen_write_cursordown(struct screen_write_ctx *, u_int);
 void	 screen_write_cursorright(struct screen_write_ctx *, u_int);
 void	 screen_write_cursorleft(struct screen_write_ctx *, u_int);
 void	 screen_write_alignmenttest(struct screen_write_ctx *);
-void	 screen_write_insertcharacter(struct screen_write_ctx *, u_int);
-void	 screen_write_deletecharacter(struct screen_write_ctx *, u_int);
+void	 screen_write_insertcharacter(struct screen_write_ctx *, u_int, u_int);
+void	 screen_write_deletecharacter(struct screen_write_ctx *, u_int, u_int);
 void	 screen_write_clearcharacter(struct screen_write_ctx *, u_int);
-void	 screen_write_insertline(struct screen_write_ctx *, u_int);
-void	 screen_write_deleteline(struct screen_write_ctx *, u_int);
-void	 screen_write_clearline(struct screen_write_ctx *);
-void	 screen_write_clearendofline(struct screen_write_ctx *);
-void	 screen_write_clearstartofline(struct screen_write_ctx *);
+void	 screen_write_insertline(struct screen_write_ctx *, u_int, u_int);
+void	 screen_write_deleteline(struct screen_write_ctx *, u_int, u_int);
+void	 screen_write_clearline(struct screen_write_ctx *, u_int);
+void	 screen_write_clearendofline(struct screen_write_ctx *, u_int);
+void	 screen_write_clearstartofline(struct screen_write_ctx *, u_int);
 void	 screen_write_cursormove(struct screen_write_ctx *, u_int, u_int);
 void	 screen_write_reverseindex(struct screen_write_ctx *);
 void	 screen_write_scrollregion(struct screen_write_ctx *, u_int, u_int);
 void	 screen_write_linefeed(struct screen_write_ctx *, int);
 void	 screen_write_carriagereturn(struct screen_write_ctx *);
-void	 screen_write_clearendofscreen(struct screen_write_ctx *);
+void	 screen_write_clearendofscreen(struct screen_write_ctx *, u_int);
 void	 screen_write_clearstartofscreen(struct screen_write_ctx *);
-void	 screen_write_clearscreen(struct screen_write_ctx *);
+void	 screen_write_clearscreen(struct screen_write_ctx *, u_int);
 void	 screen_write_clearhistory(struct screen_write_ctx *);
 void	 screen_write_cell(struct screen_write_ctx *, const struct grid_cell *);
 void	 screen_write_setselection(struct screen_write_ctx *, u_char *, u_int);