Change UTF-8 combining to inspect the previous character at the cursor

position rather than keeping the last character from the input stream,
this is how most terminals work and fixes problems with displaying these
characters in vim. GitHub issue 3600.

1 files changed, 7 insertions, 15 deletions

diff --git a/tmux.h b/tmux.h
index e12903db..9dd97adc 100644
--- a/tmux.h
+++ b/tmux.h
@@ -30,6 +30,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <termios.h>
+#include <wchar.h>
 
 #include "tmux-protocol.h"
 #include "xmalloc.h"
@@ -619,15 +620,6 @@ enum utf8_state {
 	UTF8_ERROR
 };
 
-/* UTF-8 combine state. */
-enum utf8_combine_state {
-	UTF8_DISCARD_NOW,	   /* discard immediately */
-	UTF8_WRITE_NOW,            /* do not combine, write immediately */
-	UTF8_COMBINE_NOW,          /* combine immediately */
-	UTF8_WRITE_MAYBE_COMBINE,  /* write but try to combine the next */
-	UTF8_DISCARD_MAYBE_COMBINE /* discard but try to combine the next */
-};
-
 /* Colour flags. */
 #define COLOUR_FLAG_256 0x01000000
 #define COLOUR_FLAG_RGB 0x02000000
@@ -900,7 +892,6 @@ struct screen_write_ctx {
 
 	int				 flags;
 #define SCREEN_WRITE_SYNC 0x1
-#define SCREEN_WRITE_COMBINE 0x2
 
 	screen_write_init_ctx_cb	 init_ctx_cb;
 	void				*arg;
@@ -908,7 +899,6 @@ struct screen_write_ctx {
 	struct screen_write_citem	*item;
 	u_int				 scrolled;
 	u_int				 bg;
-	struct utf8_data		 previous;
 };
 
 /* Box border lines option. */
@@ -3277,6 +3267,8 @@ u_int		 session_group_attached_count(struct session_group *);
 void		 session_renumber_windows(struct session *);
 
 /* utf8.c */
+enum utf8_state	 utf8_towc (const struct utf8_data *, wchar_t *);
+int		 utf8_in_table(wchar_t, const wchar_t *, u_int);
 utf8_char	 utf8_build_one(u_char);
 enum utf8_state	 utf8_from_data(const struct utf8_data *, utf8_char *);
 void		 utf8_to_data(utf8_char, struct utf8_data *);
@@ -3299,10 +3291,10 @@ char		*utf8_rpadcstr(const char *, u_int);
 int		 utf8_cstrhas(const char *, const struct utf8_data *);
 
 /* utf8-combined.c */
-void		 utf8_build_combined(void);
-int		 utf8_try_combined(const struct utf8_data *,
-		     const struct utf8_data *, const struct utf8_data **,
-		     u_int *width);
+int		 utf8_has_zwj(const struct utf8_data *);
+int		 utf8_is_zwj(const struct utf8_data *);
+int		 utf8_is_vs(const struct utf8_data *);
+int		 utf8_is_modifier(const struct utf8_data *);
 
 /* procname.c */
 char   *get_proc_name(int, char *);