/src/tmux/input.c

Source
/* $OpenBSD$ */

/*
 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <netinet/in.h>

#include <ctype.h>
#include <resolv.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include "tmux.h"

/*
 * Based on the description by Paul Williams at:
 *
 * https://vt100.net/emu/dec_ansi_parser
 *
 * With the following changes:
 *
 * - 7-bit only.
 *
 * - Support for UTF-8.
 *
 * - OSC (but not APC) may be terminated by \007 as well as ST.
 *
 * - A state for APC similar to OSC. Some terminals appear to use this to set
 *   the title.
 *
 * - A state for the screen \033k...\033\\ sequence to rename a window. This is
 *   pretty stupid but not supporting it is more trouble than it is worth.
 *
 * - Special handling for ESC inside a DCS to allow arbitrary byte sequences to
 *   be passed to the underlying terminals.
 */

/* Type of terminator. */
enum input_end_type {
  INPUT_END_ST,
  INPUT_END_BEL
};

/* Request sent by a pane. */
struct input_request {
  struct client     *c;
  struct input_ctx    *ictx;

  enum input_request_type    type;
  uint64_t       t;
  enum input_end_type              end;

  int        idx;
  void        *data;

  TAILQ_ENTRY(input_request)   entry;
  TAILQ_ENTRY(input_request)   centry;
};
#define INPUT_REQUEST_TIMEOUT 500

/* Input parser cell. */
struct input_cell {
  struct grid_cell  cell;
  int     set;
  int     g0set;  /* 1 if ACS */
  int     g1set;  /* 1 if ACS */
};

/* Input parser argument. */
struct input_param {
  enum {
    INPUT_MISSING,
    INPUT_NUMBER,
    INPUT_STRING
  }     type;
  union {
    int   num;
    char         *str;
  };
};

/* Input parser context. */
struct input_ctx {
  struct window_pane         *wp;
  struct bufferevent         *event;
  struct screen_write_ctx   ctx;
  struct colour_palette        *palette;
  struct client          *c;

  struct input_cell   cell;
  struct input_cell   old_cell;
  u_int       old_cx;
  u_int       old_cy;
  int       old_mode;

  u_char        interm_buf[4];
  size_t        interm_len;

  u_char        param_buf[64];
  size_t        param_len;

#define INPUT_BUF_START 32
  u_char             *input_buf;
  size_t        input_len;
  size_t        input_space;
  enum input_end_type   input_end;

  struct input_param    param_list[24];
  u_int       param_list_len;

  struct utf8_data    utf8data;
  int       utf8started;

  int       ch;
  struct utf8_data    last;

  const struct input_state       *state;
  int       flags;
#define INPUT_DISCARD 0x1
#define INPUT_LAST 0x2

  struct input_requests    requests;
  u_int        request_count;
  struct event       request_timer;

  /*
   * All input received since we were last in the ground state. Sent to
   * control clients on connection.
   */
  struct evbuffer     *since_ground;
  struct event       ground_timer;
};

/* Helper functions. */
struct input_transition;
static void   input_request_timer_callback(int, short, void *);
static void input_start_request_timer(struct input_ctx *);
static struct input_request *input_make_request(struct input_ctx *,
        enum input_request_type);
static void input_free_request(struct input_request *);
static int  input_add_request(struct input_ctx *, enum input_request_type,
        int);
static int  input_split(struct input_ctx *);
static int  input_get(struct input_ctx *, u_int, int, int);
static void input_set_state(struct input_ctx *,
        const struct input_transition *);
static void input_reset_cell(struct input_ctx *);
static void input_report_current_theme(struct input_ctx *);
static void input_osc_4(struct input_ctx *, const char *);
static void input_osc_8(struct input_ctx *, const char *);
static void input_osc_9(struct input_ctx *, const char *);
static void input_osc_10(struct input_ctx *, const char *);
static void input_osc_11(struct input_ctx *, const char *);
static void input_osc_12(struct input_ctx *, const char *);
static void input_osc_52(struct input_ctx *, const char *);
static void input_osc_104(struct input_ctx *, const char *);
static void input_osc_110(struct input_ctx *, const char *);
static void input_osc_111(struct input_ctx *, const char *);
static void input_osc_112(struct input_ctx *, const char *);
static void input_osc_133(struct input_ctx *, const char *);

/* Transition entry/exit handlers. */
static void input_clear(struct input_ctx *);
static void input_ground(struct input_ctx *);
static void input_enter_dcs(struct input_ctx *);
static void input_enter_osc(struct input_ctx *);
static void input_exit_osc(struct input_ctx *);
static void input_enter_apc(struct input_ctx *);
static void input_exit_apc(struct input_ctx *);
static void input_enter_rename(struct input_ctx *);
static void input_exit_rename(struct input_ctx *);

/* Input state handlers. */
static int  input_print(struct input_ctx *);
static int  input_intermediate(struct input_ctx *);
static int  input_parameter(struct input_ctx *);
static int  input_input(struct input_ctx *);
static int  input_c0_dispatch(struct input_ctx *);
static int  input_esc_dispatch(struct input_ctx *);
static int  input_csi_dispatch(struct input_ctx *);
static void input_csi_dispatch_rm(struct input_ctx *);
static void input_csi_dispatch_rm_private(struct input_ctx *);
static void input_csi_dispatch_sm(struct input_ctx *);
static void input_csi_dispatch_sm_private(struct input_ctx *);
static void input_csi_dispatch_sm_graphics(struct input_ctx *);
static void input_csi_dispatch_winops(struct input_ctx *);
static void input_csi_dispatch_sgr_256(struct input_ctx *, int, u_int *);
static void input_csi_dispatch_sgr_rgb(struct input_ctx *, int, u_int *);
static void input_csi_dispatch_sgr(struct input_ctx *);
static int  input_dcs_dispatch(struct input_ctx *);
static int  input_top_bit_set(struct input_ctx *);
static int  input_end_bel(struct input_ctx *);

/* Command table comparison function. */
static int  input_table_compare(const void *, const void *);

/* Command table entry. */
struct input_table_entry {
  int   ch;
  const char     *interm;
  int   type;
};

/* Escape commands. */
enum input_esc_type {
  INPUT_ESC_DECALN,
  INPUT_ESC_DECKPAM,
  INPUT_ESC_DECKPNM,
  INPUT_ESC_DECRC,
  INPUT_ESC_DECSC,
  INPUT_ESC_HTS,
  INPUT_ESC_IND,
  INPUT_ESC_NEL,
  INPUT_ESC_RI,
  INPUT_ESC_RIS,
  INPUT_ESC_SCSG0_OFF,
  INPUT_ESC_SCSG0_ON,
  INPUT_ESC_SCSG1_OFF,
  INPUT_ESC_SCSG1_ON,
  INPUT_ESC_ST
};

/* Escape command table. */
static const struct input_table_entry input_esc_table[] = {
  { '0', "(", INPUT_ESC_SCSG0_ON },
  { '0', ")", INPUT_ESC_SCSG1_ON },
  { '7', "",  INPUT_ESC_DECSC },
  { '8', "",  INPUT_ESC_DECRC },
  { '8', "#", INPUT_ESC_DECALN },
  { '=', "",  INPUT_ESC_DECKPAM },
  { '>', "",  INPUT_ESC_DECKPNM },
  { 'B', "(", INPUT_ESC_SCSG0_OFF },
  { 'B', ")", INPUT_ESC_SCSG1_OFF },
  { 'D', "",  INPUT_ESC_IND },
  { 'E', "",  INPUT_ESC_NEL },
  { 'H', "",  INPUT_ESC_HTS },
  { 'M', "",  INPUT_ESC_RI },
  { '\\', "", INPUT_ESC_ST },
  { 'c', "",  INPUT_ESC_RIS },
};

/* Control (CSI) commands. */
enum input_csi_type {
  INPUT_CSI_CBT,
  INPUT_CSI_CNL,
  INPUT_CSI_CPL,
  INPUT_CSI_CUB,
  INPUT_CSI_CUD,
  INPUT_CSI_CUF,
  INPUT_CSI_CUP,
  INPUT_CSI_CUU,
  INPUT_CSI_DA,
  INPUT_CSI_DA_TWO,
  INPUT_CSI_DCH,
  INPUT_CSI_DECSCUSR,
  INPUT_CSI_DECSTBM,
  INPUT_CSI_DL,
  INPUT_CSI_DSR,
  INPUT_CSI_DSR_PRIVATE,
  INPUT_CSI_ECH,
  INPUT_CSI_ED,
  INPUT_CSI_EL,
  INPUT_CSI_HPA,
  INPUT_CSI_ICH,
  INPUT_CSI_IL,
  INPUT_CSI_MODOFF,
  INPUT_CSI_MODSET,
  INPUT_CSI_QUERY_PRIVATE,
  INPUT_CSI_RCP,
  INPUT_CSI_REP,
  INPUT_CSI_RM,
  INPUT_CSI_RM_PRIVATE,
  INPUT_CSI_SCP,
  INPUT_CSI_SD,
  INPUT_CSI_SGR,
  INPUT_CSI_SM,
  INPUT_CSI_SM_GRAPHICS,
  INPUT_CSI_SM_PRIVATE,
  INPUT_CSI_SU,
  INPUT_CSI_TBC,
  INPUT_CSI_VPA,
  INPUT_CSI_WINOPS,
  INPUT_CSI_XDA
};

/* Control (CSI) command table. */
static const struct input_table_entry input_csi_table[] = {
  { '@', "",  INPUT_CSI_ICH },
  { 'A', "",  INPUT_CSI_CUU },
  { 'B', "",  INPUT_CSI_CUD },
  { 'C', "",  INPUT_CSI_CUF },
  { 'D', "",  INPUT_CSI_CUB },
  { 'E', "",  INPUT_CSI_CNL },
  { 'F', "",  INPUT_CSI_CPL },
  { 'G', "",  INPUT_CSI_HPA },
  { 'H', "",  INPUT_CSI_CUP },
  { 'J', "",  INPUT_CSI_ED },
  { 'K', "",  INPUT_CSI_EL },
  { 'L', "",  INPUT_CSI_IL },
  { 'M', "",  INPUT_CSI_DL },
  { 'P', "",  INPUT_CSI_DCH },
  { 'S', "",  INPUT_CSI_SU },
  { 'S', "?", INPUT_CSI_SM_GRAPHICS },
  { 'T', "",  INPUT_CSI_SD },
  { 'X', "",  INPUT_CSI_ECH },
  { 'Z', "",  INPUT_CSI_CBT },
  { '`', "",  INPUT_CSI_HPA },
  { 'b', "",  INPUT_CSI_REP },
  { 'c', "",  INPUT_CSI_DA },
  { 'c', ">", INPUT_CSI_DA_TWO },
  { 'd', "",  INPUT_CSI_VPA },
  { 'f', "",  INPUT_CSI_CUP },
  { 'g', "",  INPUT_CSI_TBC },
  { 'h', "",  INPUT_CSI_SM },
  { 'h', "?", INPUT_CSI_SM_PRIVATE },
  { 'l', "",  INPUT_CSI_RM },
  { 'l', "?", INPUT_CSI_RM_PRIVATE },
  { 'm', "",  INPUT_CSI_SGR },
  { 'm', ">", INPUT_CSI_MODSET },
  { 'n', "",  INPUT_CSI_DSR },
  { 'n', ">", INPUT_CSI_MODOFF },
  { 'n', "?", INPUT_CSI_DSR_PRIVATE },
  { 'p', "?$", INPUT_CSI_QUERY_PRIVATE },
  { 'q', " ", INPUT_CSI_DECSCUSR },
  { 'q', ">", INPUT_CSI_XDA },
  { 'r', "",  INPUT_CSI_DECSTBM },
  { 's', "",  INPUT_CSI_SCP },
  { 't', "",  INPUT_CSI_WINOPS },
  { 'u', "",  INPUT_CSI_RCP }
};

/* Input transition. */
struct input_transition {
  int       first;
  int       last;

  int       (*handler)(struct input_ctx *);
  const struct input_state       *state;
};

/* Input state. */
struct input_state {
  const char      *name;
  void        (*enter)(struct input_ctx *);
  void        (*exit)(struct input_ctx *);
  const struct input_transition *transitions;
};

/* State transitions available from all states. */
#define INPUT_STATE_ANYWHERE \
  { 0x18, 0x18, input_c0_dispatch, &input_state_ground }, \
  { 0x1a, 0x1a, input_c0_dispatch, &input_state_ground }, \
  { 0x1b, 0x1b, NULL,    &input_state_esc_enter }

/* Forward declarations of state tables. */
static const struct input_transition input_state_ground_table[];
static const struct input_transition input_state_esc_enter_table[];
static const struct input_transition input_state_esc_intermediate_table[];
static const struct input_transition input_state_csi_enter_table[];
static const struct input_transition input_state_csi_parameter_table[];
static const struct input_transition input_state_csi_intermediate_table[];
static const struct input_transition input_state_csi_ignore_table[];
static const struct input_transition input_state_dcs_enter_table[];
static const struct input_transition input_state_dcs_parameter_table[];
static const struct input_transition input_state_dcs_intermediate_table[];
static const struct input_transition input_state_dcs_handler_table[];
static const struct input_transition input_state_dcs_escape_table[];
static const struct input_transition input_state_dcs_ignore_table[];
static const struct input_transition input_state_osc_string_table[];
static const struct input_transition input_state_apc_string_table[];
static const struct input_transition input_state_rename_string_table[];
static const struct input_transition input_state_consume_st_table[];

/* ground state definition. */
static const struct input_state input_state_ground = {
  "ground",
  input_ground, NULL,
  input_state_ground_table
};

/* esc_enter state definition. */
static const struct input_state input_state_esc_enter = {
  "esc_enter",
  input_clear, NULL,
  input_state_esc_enter_table
};

/* esc_intermediate state definition. */
static const struct input_state input_state_esc_intermediate = {
  "esc_intermediate",
  NULL, NULL,
  input_state_esc_intermediate_table
};

/* csi_enter state definition. */
static const struct input_state input_state_csi_enter = {
  "csi_enter",
  input_clear, NULL,
  input_state_csi_enter_table
};

/* csi_parameter state definition. */
static const struct input_state input_state_csi_parameter = {
  "csi_parameter",
  NULL, NULL,
  input_state_csi_parameter_table
};

/* csi_intermediate state definition. */
static const struct input_state input_state_csi_intermediate = {
  "csi_intermediate",
  NULL, NULL,
  input_state_csi_intermediate_table
};

/* csi_ignore state definition. */
static const struct input_state input_state_csi_ignore = {
  "csi_ignore",
  NULL, NULL,
  input_state_csi_ignore_table
};

/* dcs_enter state definition. */
static const struct input_state input_state_dcs_enter = {
  "dcs_enter",
  input_enter_dcs, NULL,
  input_state_dcs_enter_table
};

/* dcs_parameter state definition. */
static const struct input_state input_state_dcs_parameter = {
  "dcs_parameter",
  NULL, NULL,
  input_state_dcs_parameter_table
};

/* dcs_intermediate state definition. */
static const struct input_state input_state_dcs_intermediate = {
  "dcs_intermediate",
  NULL, NULL,
  input_state_dcs_intermediate_table
};

/* dcs_handler state definition. */
static const struct input_state input_state_dcs_handler = {
  "dcs_handler",
  NULL, NULL,
  input_state_dcs_handler_table
};

/* dcs_escape state definition. */
static const struct input_state input_state_dcs_escape = {
  "dcs_escape",
  NULL, NULL,
  input_state_dcs_escape_table
};

/* dcs_ignore state definition. */
static const struct input_state input_state_dcs_ignore = {
  "dcs_ignore",
  NULL, NULL,
  input_state_dcs_ignore_table
};

/* osc_string state definition. */
static const struct input_state input_state_osc_string = {
  "osc_string",
  input_enter_osc, input_exit_osc,
  input_state_osc_string_table
};

/* apc_string state definition. */
static const struct input_state input_state_apc_string = {
  "apc_string",
  input_enter_apc, input_exit_apc,
  input_state_apc_string_table
};

/* rename_string state definition. */
static const struct input_state input_state_rename_string = {
  "rename_string",
  input_enter_rename, input_exit_rename,
  input_state_rename_string_table
};

/* consume_st state definition. */
static const struct input_state input_state_consume_st = {
  "consume_st",
  input_enter_rename, NULL, /* rename also waits for ST */
  input_state_consume_st_table
};

/* ground state table. */
static const struct input_transition input_state_ground_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, input_c0_dispatch, NULL },
  { 0x19, 0x19, input_c0_dispatch, NULL },
  { 0x1c, 0x1f, input_c0_dispatch, NULL },
  { 0x20, 0x7e, input_print,   NULL },
  { 0x7f, 0x7f, NULL,    NULL },
  { 0x80, 0xff, input_top_bit_set, NULL },

  { -1, -1, NULL, NULL }
};

/* esc_enter state table. */
static const struct input_transition input_state_esc_enter_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, input_c0_dispatch,  NULL },
  { 0x19, 0x19, input_c0_dispatch,  NULL },
  { 0x1c, 0x1f, input_c0_dispatch,  NULL },
  { 0x20, 0x2f, input_intermediate, &input_state_esc_intermediate },
  { 0x30, 0x4f, input_esc_dispatch, &input_state_ground },
  { 0x50, 0x50, NULL,     &input_state_dcs_enter },
  { 0x51, 0x57, input_esc_dispatch, &input_state_ground },
  { 0x58, 0x58, NULL,     &input_state_consume_st },
  { 0x59, 0x59, input_esc_dispatch, &input_state_ground },
  { 0x5a, 0x5a, input_esc_dispatch, &input_state_ground },
  { 0x5b, 0x5b, NULL,     &input_state_csi_enter },
  { 0x5c, 0x5c, input_esc_dispatch, &input_state_ground },
  { 0x5d, 0x5d, NULL,     &input_state_osc_string },
  { 0x5e, 0x5e, NULL,     &input_state_consume_st },
  { 0x5f, 0x5f, NULL,     &input_state_apc_string },
  { 0x60, 0x6a, input_esc_dispatch, &input_state_ground },
  { 0x6b, 0x6b, NULL,     &input_state_rename_string },
  { 0x6c, 0x7e, input_esc_dispatch, &input_state_ground },
  { 0x7f, 0xff, NULL,     NULL },

  { -1, -1, NULL, NULL }
};

/* esc_intermediate state table. */
static const struct input_transition input_state_esc_intermediate_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, input_c0_dispatch,  NULL },
  { 0x19, 0x19, input_c0_dispatch,  NULL },
  { 0x1c, 0x1f, input_c0_dispatch,  NULL },
  { 0x20, 0x2f, input_intermediate, NULL },
  { 0x30, 0x7e, input_esc_dispatch, &input_state_ground },
  { 0x7f, 0xff, NULL,     NULL },

  { -1, -1, NULL, NULL }
};

/* csi_enter state table. */
static const struct input_transition input_state_csi_enter_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, input_c0_dispatch,  NULL },
  { 0x19, 0x19, input_c0_dispatch,  NULL },
  { 0x1c, 0x1f, input_c0_dispatch,  NULL },
  { 0x20, 0x2f, input_intermediate, &input_state_csi_intermediate },
  { 0x30, 0x39, input_parameter,    &input_state_csi_parameter },
  { 0x3a, 0x3a, input_parameter,    &input_state_csi_parameter },
  { 0x3b, 0x3b, input_parameter,    &input_state_csi_parameter },
  { 0x3c, 0x3f, input_intermediate, &input_state_csi_parameter },
  { 0x40, 0x7e, input_csi_dispatch, &input_state_ground },
  { 0x7f, 0xff, NULL,     NULL },

  { -1, -1, NULL, NULL }
};

/* csi_parameter state table. */
static const struct input_transition input_state_csi_parameter_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, input_c0_dispatch,  NULL },
  { 0x19, 0x19, input_c0_dispatch,  NULL },
  { 0x1c, 0x1f, input_c0_dispatch,  NULL },
  { 0x20, 0x2f, input_intermediate, &input_state_csi_intermediate },
  { 0x30, 0x39, input_parameter,    NULL },
  { 0x3a, 0x3a, input_parameter,    NULL },
  { 0x3b, 0x3b, input_parameter,    NULL },
  { 0x3c, 0x3f, NULL,     &input_state_csi_ignore },
  { 0x40, 0x7e, input_csi_dispatch, &input_state_ground },
  { 0x7f, 0xff, NULL,     NULL },

  { -1, -1, NULL, NULL }
};

/* csi_intermediate state table. */
static const struct input_transition input_state_csi_intermediate_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, input_c0_dispatch,  NULL },
  { 0x19, 0x19, input_c0_dispatch,  NULL },
  { 0x1c, 0x1f, input_c0_dispatch,  NULL },
  { 0x20, 0x2f, input_intermediate, NULL },
  { 0x30, 0x3f, NULL,     &input_state_csi_ignore },
  { 0x40, 0x7e, input_csi_dispatch, &input_state_ground },
  { 0x7f, 0xff, NULL,     NULL },

  { -1, -1, NULL, NULL }
};

/* csi_ignore state table. */
static const struct input_transition input_state_csi_ignore_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, input_c0_dispatch, NULL },
  { 0x19, 0x19, input_c0_dispatch, NULL },
  { 0x1c, 0x1f, input_c0_dispatch, NULL },
  { 0x20, 0x3f, NULL,    NULL },
  { 0x40, 0x7e, NULL,    &input_state_ground },
  { 0x7f, 0xff, NULL,    NULL },

  { -1, -1, NULL, NULL }
};

/* dcs_enter state table. */
static const struct input_transition input_state_dcs_enter_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, NULL,     NULL },
  { 0x19, 0x19, NULL,     NULL },
  { 0x1c, 0x1f, NULL,     NULL },
  { 0x20, 0x2f, input_intermediate, &input_state_dcs_intermediate },
  { 0x30, 0x39, input_parameter,    &input_state_dcs_parameter },
  { 0x3a, 0x3a, NULL,     &input_state_dcs_ignore },
  { 0x3b, 0x3b, input_parameter,    &input_state_dcs_parameter },
  { 0x3c, 0x3f, input_intermediate, &input_state_dcs_parameter },
  { 0x40, 0x7e, input_input,    &input_state_dcs_handler },
  { 0x7f, 0xff, NULL,     NULL },

  { -1, -1, NULL, NULL }
};

/* dcs_parameter state table. */
static const struct input_transition input_state_dcs_parameter_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, NULL,     NULL },
  { 0x19, 0x19, NULL,     NULL },
  { 0x1c, 0x1f, NULL,     NULL },
  { 0x20, 0x2f, input_intermediate, &input_state_dcs_intermediate },
  { 0x30, 0x39, input_parameter,    NULL },
  { 0x3a, 0x3a, NULL,     &input_state_dcs_ignore },
  { 0x3b, 0x3b, input_parameter,    NULL },
  { 0x3c, 0x3f, NULL,     &input_state_dcs_ignore },
  { 0x40, 0x7e, input_input,    &input_state_dcs_handler },
  { 0x7f, 0xff, NULL,     NULL },

  { -1, -1, NULL, NULL }
};

/* dcs_intermediate state table. */
static const struct input_transition input_state_dcs_intermediate_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, NULL,     NULL },
  { 0x19, 0x19, NULL,     NULL },
  { 0x1c, 0x1f, NULL,     NULL },
  { 0x20, 0x2f, input_intermediate, NULL },
  { 0x30, 0x3f, NULL,     &input_state_dcs_ignore },
  { 0x40, 0x7e, input_input,    &input_state_dcs_handler },
  { 0x7f, 0xff, NULL,     NULL },

  { -1, -1, NULL, NULL }
};

/* dcs_handler state table. */
static const struct input_transition input_state_dcs_handler_table[] = {
  /* No INPUT_STATE_ANYWHERE */

  { 0x00, 0x1a, input_input,  NULL },
  { 0x1b, 0x1b, NULL,     &input_state_dcs_escape },
  { 0x1c, 0xff, input_input,  NULL },

  { -1, -1, NULL, NULL }
};

/* dcs_escape state table. */
static const struct input_transition input_state_dcs_escape_table[] = {
  /* No INPUT_STATE_ANYWHERE */

  { 0x00, 0x5b, input_input,    &input_state_dcs_handler },
  { 0x5c, 0x5c, input_dcs_dispatch, &input_state_ground },
  { 0x5d, 0xff, input_input,    &input_state_dcs_handler },

  { -1, -1, NULL, NULL }
};

/* dcs_ignore state table. */
static const struct input_transition input_state_dcs_ignore_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, NULL,     NULL },
  { 0x19, 0x19, NULL,     NULL },
  { 0x1c, 0x1f, NULL,     NULL },
  { 0x20, 0xff, NULL,     NULL },

  { -1, -1, NULL, NULL }
};

/* osc_string state table. */
static const struct input_transition input_state_osc_string_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x06, NULL,      NULL },
  { 0x07, 0x07, input_end_bel, &input_state_ground },
  { 0x08, 0x17, NULL,      NULL },
  { 0x19, 0x19, NULL,      NULL },
  { 0x1c, 0x1f, NULL,      NULL },
  { 0x20, 0xff, input_input,   NULL },

  { -1, -1, NULL, NULL }
};

/* apc_string state table. */
static const struct input_transition input_state_apc_string_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, NULL,     NULL },
  { 0x19, 0x19, NULL,     NULL },
  { 0x1c, 0x1f, NULL,     NULL },
  { 0x20, 0xff, input_input,  NULL },

  { -1, -1, NULL, NULL }
};

/* rename_string state table. */
static const struct input_transition input_state_rename_string_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, NULL,     NULL },
  { 0x19, 0x19, NULL,     NULL },
  { 0x1c, 0x1f, NULL,     NULL },
  { 0x20, 0xff, input_input,  NULL },

  { -1, -1, NULL, NULL }
};

/* consume_st state table. */
static const struct input_transition input_state_consume_st_table[] = {
  INPUT_STATE_ANYWHERE,

  { 0x00, 0x17, NULL,     NULL },
  { 0x19, 0x19, NULL,     NULL },
  { 0x1c, 0x1f, NULL,     NULL },
  { 0x20, 0xff, NULL,     NULL },

  { -1, -1, NULL, NULL }
};

/* Maximum of bytes allowed to read in a single input. */
static size_t input_buffer_size = INPUT_BUF_DEFAULT_SIZE;

/* Input table compare. */
static int
input_table_compare(const void *key, const void *value)
{
  const struct input_ctx    *ictx = key;
  const struct input_table_entry  *entry = value;

  if (ictx->ch != entry->ch)
    return (ictx->ch - entry->ch);
  return (strcmp(ictx->interm_buf, entry->interm));
}

/* Stop UTF-8 and enter an invalid character. */
static void
input_stop_utf8(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  static struct utf8_data  rc = { "\357\277\275", 3, 3, 1 };

  if (ictx->utf8started) {
    utf8_copy(&ictx->cell.cell.data, &rc);
    screen_write_collect_add(sctx, &ictx->cell.cell);
  }
  ictx->utf8started = 0;
}

/*
 * Timer - if this expires then have been waiting for a terminator for too
 * long, so reset to ground.
 */
static void
input_ground_timer_callback(__unused int fd, __unused short events, void *arg)
{
  struct input_ctx  *ictx = arg;

  log_debug("%s: %s expired" , __func__, ictx->state->name);
  input_reset(ictx, 0);
}

/* Start the timer. */
static void
input_start_ground_timer(struct input_ctx *ictx)
{
  struct timeval  tv = { .tv_sec = 5, .tv_usec = 0 };

  event_del(&ictx->ground_timer);
  event_add(&ictx->ground_timer, &tv);
}

/* Reset cell state to default. */
static void
input_reset_cell(struct input_ctx *ictx)
{
  memcpy(&ictx->cell.cell, &grid_default_cell, sizeof ictx->cell.cell);
  ictx->cell.set = 0;
  ictx->cell.g0set = ictx->cell.g1set = 0;

  memcpy(&ictx->old_cell, &ictx->cell, sizeof ictx->old_cell);
  ictx->old_cx = 0;
  ictx->old_cy = 0;
}

/* Save screen state. */
static void
input_save_state(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  struct screen   *s = sctx->s;

  memcpy(&ictx->old_cell, &ictx->cell, sizeof ictx->old_cell);
  ictx->old_cx = s->cx;
  ictx->old_cy = s->cy;
  ictx->old_mode = s->mode;
}

/* Restore screen state. */
static void
input_restore_state(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;

  memcpy(&ictx->cell, &ictx->old_cell, sizeof ictx->cell);
  if (ictx->old_mode & MODE_ORIGIN)
    screen_write_mode_set(sctx, MODE_ORIGIN);
  else
    screen_write_mode_clear(sctx, MODE_ORIGIN);
  screen_write_cursormove(sctx, ictx->old_cx, ictx->old_cy, 0);
}

/* Initialise input parser. */
struct input_ctx *
input_init(struct window_pane *wp, struct bufferevent *bev,
    struct colour_palette *palette, struct client *c)
{
  struct input_ctx  *ictx;

  ictx = xcalloc(1, sizeof *ictx);
  ictx->wp = wp;
  ictx->event = bev;
  ictx->palette = palette;
  ictx->c = c;

  ictx->input_space = INPUT_BUF_START;
  ictx->input_buf = xmalloc(INPUT_BUF_START);

  ictx->since_ground = evbuffer_new();
  if (ictx->since_ground == NULL)
    fatalx("out of memory");
  evtimer_set(&ictx->ground_timer, input_ground_timer_callback, ictx);

  TAILQ_INIT(&ictx->requests);
  evtimer_set(&ictx->request_timer, input_request_timer_callback, ictx);

  input_reset(ictx, 0);
  return (ictx);
}

/* Destroy input parser. */
void
input_free(struct input_ctx *ictx)
{
  struct input_request  *ir, *ir1;
  u_int      i;

  for (i = 0; i < ictx->param_list_len; i++) {
    if (ictx->param_list[i].type == INPUT_STRING)
      free(ictx->param_list[i].str);
  }

  TAILQ_FOREACH_SAFE(ir, &ictx->requests, entry, ir1)
    input_free_request(ir);
  event_del(&ictx->request_timer);

  free(ictx->input_buf);
  evbuffer_free(ictx->since_ground);
  event_del(&ictx->ground_timer);

  screen_write_stop_sync(ictx->wp);

  free(ictx);
}

/* Reset input state and clear screen. */
void
input_reset(struct input_ctx *ictx, int clear)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  struct window_pane  *wp = ictx->wp;

  input_reset_cell(ictx);

  if (clear && wp != NULL) {
    if (TAILQ_EMPTY(&wp->modes))
      screen_write_start_pane(sctx, wp, &wp->base);
    else
      screen_write_start(sctx, &wp->base);
    screen_write_reset(sctx);
    screen_write_stop(sctx);
  }

  input_clear(ictx);

  ictx->state = &input_state_ground;
  ictx->flags = 0;
}

/* Return pending data. */
struct evbuffer *
input_pending(struct input_ctx *ictx)
{
  return (ictx->since_ground);
}

/* Change input state. */
static void
input_set_state(struct input_ctx *ictx, const struct input_transition *itr)
{
  if (ictx->state->exit != NULL)
    ictx->state->exit(ictx);
  ictx->state = itr->state;
  if (ictx->state->enter != NULL)
    ictx->state->enter(ictx);
}

/* Parse data. */
static void
input_parse(struct input_ctx *ictx, const u_char *buf, size_t len)
{
  struct screen_write_ctx   *sctx = &ictx->ctx;
  const struct input_state  *state = NULL;
  const struct input_transition *itr = NULL;
  size_t         off = 0;

  /* Parse the input. */
  while (off < len) {
    ictx->ch = buf[off++];

    /* Find the transition. */
    if (ictx->state != state ||
        itr == NULL ||
        ictx->ch < itr->first ||
        ictx->ch > itr->last) {
      itr = ictx->state->transitions;
      while (itr->first != -1 && itr->last != -1) {
        if (ictx->ch >= itr->first &&
            ictx->ch <= itr->last)
          break;
        itr++;
      }
      if (itr->first == -1 || itr->last == -1) {
        /* No transition? Eh? */
        fatalx("no transition from state");
      }
    }
    state = ictx->state;

    /*
     * Any state except print stops the current collection. This is
     * an optimization to avoid checking if the attributes have
     * changed for every character. It will stop unnecessarily for
     * sequences that don't make a terminal change, but they should
     * be the minority.
     */
    if (itr->handler != input_print)
      screen_write_collect_end(sctx);

    /*
     * Execute the handler, if any. Don't switch state if it
     * returns non-zero.
     */
    if (itr->handler != NULL && itr->handler(ictx) != 0)
      continue;

    /* And switch state, if necessary. */
    if (itr->state != NULL)
      input_set_state(ictx, itr);

    /* If not in ground state, save input. */
    if (ictx->state != &input_state_ground)
      evbuffer_add(ictx->since_ground, &ictx->ch, 1);
  }
}

/* Parse input from pane. */
void
input_parse_pane(struct window_pane *wp)
{
  void  *new_data;
  size_t   new_size;

  new_data = window_pane_get_new_data(wp, &wp->offset, &new_size);
  input_parse_buffer(wp, new_data, new_size);
  window_pane_update_used_data(wp, &wp->offset, new_size);
}

/* Parse given input. */
void
input_parse_buffer(struct window_pane *wp, const u_char *buf, size_t len)
{
  struct input_ctx  *ictx = wp->ictx;
  struct screen_write_ctx *sctx = &ictx->ctx;

  if (len == 0)
    return;

  window_update_activity(wp->window);
  wp->flags |= PANE_CHANGED;

  /* Flag new input while in a mode. */
  if (!TAILQ_EMPTY(&wp->modes))
    wp->flags |= PANE_UNSEENCHANGES;

  /* NULL wp if there is a mode set as don't want to update the tty. */
  if (TAILQ_EMPTY(&wp->modes))
    screen_write_start_pane(sctx, wp, &wp->base);
  else
    screen_write_start(sctx, &wp->base);

  log_debug("%s: %%%u %s, %zu bytes: %.*s", __func__, wp->id,
      ictx->state->name, len, (int)len, buf);

  input_parse(ictx, buf, len);
  screen_write_stop(sctx);
}

/* Parse given input for screen. */
void
input_parse_screen(struct input_ctx *ictx, struct screen *s,
    screen_write_init_ctx_cb cb, void *arg, const u_char *buf, size_t len)
{
  struct screen_write_ctx *sctx = &ictx->ctx;

  if (len == 0)
    return;

  screen_write_start_callback(sctx, s, cb, arg);
  input_parse(ictx, buf, len);
  screen_write_stop(sctx);
}

/* Split the parameter list (if any). */
static int
input_split(struct input_ctx *ictx)
{
  const char    *errstr;
  char      *ptr, *out;
  struct input_param  *ip;
  u_int      i;

  for (i = 0; i < ictx->param_list_len; i++) {
    if (ictx->param_list[i].type == INPUT_STRING)
      free(ictx->param_list[i].str);
  }
  ictx->param_list_len = 0;

  if (ictx->param_len == 0)
    return (0);
  ip = &ictx->param_list[0];

  ptr = ictx->param_buf;
  while ((out = strsep(&ptr, ";")) != NULL) {
    if (*out == '\0')
      ip->type = INPUT_MISSING;
    else {
      if (strchr(out, ':') != NULL) {
        ip->type = INPUT_STRING;
        ip->str = xstrdup(out);
      } else {
        ip->type = INPUT_NUMBER;
        ip->num = strtonum(out, 0, INT_MAX, &errstr);
        if (errstr != NULL)
          return (-1);
      }
    }
    ip = &ictx->param_list[++ictx->param_list_len];
    if (ictx->param_list_len == nitems(ictx->param_list))
      return (-1);
  }

  for (i = 0; i < ictx->param_list_len; i++) {
    ip = &ictx->param_list[i];
    if (ip->type == INPUT_MISSING)
      log_debug("parameter %u: missing", i);
    else if (ip->type == INPUT_STRING)
      log_debug("parameter %u: string %s", i, ip->str);
    else if (ip->type == INPUT_NUMBER)
      log_debug("parameter %u: number %d", i, ip->num);
  }

  return (0);
}

/* Get an argument or return default value. */
static int
input_get(struct input_ctx *ictx, u_int validx, int minval, int defval)
{
  struct input_param  *ip;
  int      retval;

  if (validx >= ictx->param_list_len)
      return (defval);
  ip = &ictx->param_list[validx];
  if (ip->type == INPUT_MISSING)
    return (defval);
  if (ip->type == INPUT_STRING)
    return (-1);
  retval = ip->num;
  if (retval < minval)
    return (minval);
  return (retval);
}

/* Send reply. */
static void
input_send_reply(struct input_ctx *ictx, const char *reply)
{
  if (ictx->event != NULL) {
    log_debug("%s: %s", __func__, reply);
    bufferevent_write(ictx->event, reply, strlen(reply));
  }
}

/* Reply to terminal query. */
static void printflike(3, 4)
input_reply(struct input_ctx *ictx, int add, const char *fmt, ...)
{
  struct input_request  *ir;
  va_list      ap;
  char      *reply;

  va_start(ap, fmt);
  xvasprintf(&reply, fmt, ap);
  va_end(ap);

  if (add && !TAILQ_EMPTY(&ictx->requests)) {
    ir = input_make_request(ictx, INPUT_REQUEST_QUEUE);
    ir->data = reply;
  } else {
    input_send_reply(ictx, reply);
    free(reply);
  }
}

/* Clear saved state. */
static void
input_clear(struct input_ctx *ictx)
{
  event_del(&ictx->ground_timer);

  *ictx->interm_buf = '\0';
  ictx->interm_len = 0;

  *ictx->param_buf = '\0';
  ictx->param_len = 0;

  *ictx->input_buf = '\0';
  ictx->input_len = 0;

  ictx->input_end = INPUT_END_ST;

  ictx->flags &= ~INPUT_DISCARD;
}

/* Reset for ground state. */
static void
input_ground(struct input_ctx *ictx)
{
  event_del(&ictx->ground_timer);
  evbuffer_drain(ictx->since_ground, EVBUFFER_LENGTH(ictx->since_ground));

  if (ictx->input_space > INPUT_BUF_START) {
    ictx->input_space = INPUT_BUF_START;
    ictx->input_buf = xrealloc(ictx->input_buf, INPUT_BUF_START);
  }
}

/* Output this character to the screen. */
static int
input_print(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  int      set;

  input_stop_utf8(ictx); /* can't be valid UTF-8 */

  set = ictx->cell.set == 0 ? ictx->cell.g0set : ictx->cell.g1set;
  if (set == 1)
    ictx->cell.cell.attr |= GRID_ATTR_CHARSET;
  else
    ictx->cell.cell.attr &= ~GRID_ATTR_CHARSET;
  utf8_set(&ictx->cell.cell.data, ictx->ch);
  screen_write_collect_add(sctx, &ictx->cell.cell);

  utf8_copy(&ictx->last, &ictx->cell.cell.data);
  ictx->flags |= INPUT_LAST;

  ictx->cell.cell.attr &= ~GRID_ATTR_CHARSET;

  return (0);
}

/* Collect intermediate string. */
static int
input_intermediate(struct input_ctx *ictx)
{
  if (ictx->interm_len == (sizeof ictx->interm_buf) - 1)
    ictx->flags |= INPUT_DISCARD;
  else {
    ictx->interm_buf[ictx->interm_len++] = ictx->ch;
    ictx->interm_buf[ictx->interm_len] = '\0';
  }

  return (0);
}

/* Collect parameter string. */
static int
input_parameter(struct input_ctx *ictx)
{
  if (ictx->param_len == (sizeof ictx->param_buf) - 1)
    ictx->flags |= INPUT_DISCARD;
  else {
    ictx->param_buf[ictx->param_len++] = ictx->ch;
    ictx->param_buf[ictx->param_len] = '\0';
  }

  return (0);
}

/* Collect input string. */
static int
input_input(struct input_ctx *ictx)
{
  size_t available;

  available = ictx->input_space;
  while (ictx->input_len + 1 >= available) {
    available *= 2;
    if (available > input_buffer_size) {
      ictx->flags |= INPUT_DISCARD;
      return (0);
    }
    ictx->input_buf = xrealloc(ictx->input_buf, available);
    ictx->input_space = available;
  }
  ictx->input_buf[ictx->input_len++] = ictx->ch;
  ictx->input_buf[ictx->input_len] = '\0';

  return (0);
}

/* Execute C0 control sequence. */
static int
input_c0_dispatch(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  struct window_pane  *wp = ictx->wp;
  struct screen   *s = sctx->s;
  struct grid_cell   gc, first_gc;
  u_int      cx, line;
  u_int      width;
  int      has_content = 0;

  input_stop_utf8(ictx); /* can't be valid UTF-8 */

  log_debug("%s: '%c'", __func__, ictx->ch);

  switch (ictx->ch) {
  case '\000':  /* NUL */
    break;
  case '\007':  /* BEL */
    if (wp != NULL)
      alerts_queue(wp->window, WINDOW_BELL);
    break;
  case '\010':  /* BS */
    screen_write_backspace(sctx);
    break;
  case '\011':  /* HT */
    /* Don't tab beyond the end of the line. */
    cx = s->cx;
    if (cx >= screen_size_x(s) - 1)
      break;

    /* Find the next tab point, or use the last column if none. */
    line = s->cy + s->grid->hsize;
    grid_get_cell(s->grid, cx, line, &first_gc);
    do {
      if (!has_content) {
        grid_get_cell(s->grid, cx, line, &gc);
        if (gc.data.size != 1 ||
            *gc.data.data != ' ' ||
            !grid_cells_look_equal(&gc, &first_gc))
          has_content = 1;
      }
      cx++;
      if (bit_test(s->tabs, cx))
        break;
    } while (cx < screen_size_x(s) - 1);

    width = cx - s->cx;
    if (has_content || width > sizeof gc.data.data)
      s->cx = cx;
    else {
      grid_get_cell(s->grid, s->cx, line, &gc);
      grid_set_tab(&gc, width);
      screen_write_collect_add(sctx, &gc);
    }
    break;
  case '\012':  /* LF */
  case '\013':  /* VT */
  case '\014':  /* FF */
    screen_write_linefeed(sctx, 0, ictx->cell.cell.bg);
    if (s->mode & MODE_CRLF)
      screen_write_carriagereturn(sctx);
    break;
  case '\015':  /* CR */
    screen_write_carriagereturn(sctx);
    break;
  case '\016':  /* SO */
    ictx->cell.set = 1;
    break;
  case '\017':  /* SI */
    ictx->cell.set = 0;
    break;
  default:
    log_debug("%s: unknown '%c'", __func__, ictx->ch);
    break;
  }

  ictx->flags &= ~INPUT_LAST;
  return (0);
}

/* Execute escape sequence. */
static int
input_esc_dispatch(struct input_ctx *ictx)
{
  struct screen_write_ctx   *sctx = &ictx->ctx;
  struct screen     *s = sctx->s;
  struct input_table_entry  *entry;

  if (ictx->flags & INPUT_DISCARD)
    return (0);
  log_debug("%s: '%c', %s", __func__, ictx->ch, ictx->interm_buf);

  entry = bsearch(ictx, input_esc_table, nitems(input_esc_table),
      sizeof input_esc_table[0], input_table_compare);
  if (entry == NULL) {
    log_debug("%s: unknown '%c'", __func__, ictx->ch);
    return (0);
  }

  switch (entry->type) {
  case INPUT_ESC_RIS:
    colour_palette_clear(ictx->palette);
    input_reset_cell(ictx);
    screen_write_reset(sctx);
    screen_write_fullredraw(sctx);
    break;
  case INPUT_ESC_IND:
    screen_write_linefeed(sctx, 0, ictx->cell.cell.bg);
    break;
  case INPUT_ESC_NEL:
    screen_write_carriagereturn(sctx);
    screen_write_linefeed(sctx, 0, ictx->cell.cell.bg);
    break;
  case INPUT_ESC_HTS:
    if (s->cx < screen_size_x(s))
      bit_set(s->tabs, s->cx);
    break;
  case INPUT_ESC_RI:
    screen_write_reverseindex(sctx, ictx->cell.cell.bg);
    break;
  case INPUT_ESC_DECKPAM:
    screen_write_mode_set(sctx, MODE_KKEYPAD);
    break;
  case INPUT_ESC_DECKPNM:
    screen_write_mode_clear(sctx, MODE_KKEYPAD);
    break;
  case INPUT_ESC_DECSC:
    input_save_state(ictx);
    break;
  case INPUT_ESC_DECRC:
    input_restore_state(ictx);
    break;
  case INPUT_ESC_DECALN:
    screen_write_alignmenttest(sctx);
    break;
  case INPUT_ESC_SCSG0_ON:
    ictx->cell.g0set = 1;
    break;
  case INPUT_ESC_SCSG0_OFF:
    ictx->cell.g0set = 0;
    break;
  case INPUT_ESC_SCSG1_ON:
    ictx->cell.g1set = 1;
    break;
  case INPUT_ESC_SCSG1_OFF:
    ictx->cell.g1set = 0;
    break;
  case INPUT_ESC_ST:
    /* ST terminates OSC but the state transition already did it. */
    break;
  }

  ictx->flags &= ~INPUT_LAST;
  return (0);
}

/* Execute control sequence. */
static int
input_csi_dispatch(struct input_ctx *ictx)
{
  struct screen_write_ctx        *sctx = &ictx->ctx;
  struct screen          *s = sctx->s;
  struct input_table_entry       *entry;
  struct options           *oo;
  int       i, n, m, ek, set, p;
  u_int       cx, bg = ictx->cell.cell.bg;

  if (ictx->flags & INPUT_DISCARD)
    return (0);

  log_debug("%s: '%c' \"%s\" \"%s\"", __func__, ictx->ch,
      ictx->interm_buf, ictx->param_buf);

  if (input_split(ictx) != 0)
    return (0);

  entry = bsearch(ictx, input_csi_table, nitems(input_csi_table),
      sizeof input_csi_table[0], input_table_compare);
  if (entry == NULL) {
    log_debug("%s: unknown '%c'", __func__, ictx->ch);
    return (0);
  }

  switch (entry->type) {
  case INPUT_CSI_CBT:
    /* Find the previous tab point, n times. */
    cx = s->cx;
    if (cx > screen_size_x(s) - 1)
      cx = screen_size_x(s) - 1;
    n = input_get(ictx, 0, 1, 1);
    if (n == -1)
      break;
    while (cx > 0 && n-- > 0) {
      do
        cx--;
      while (cx > 0 && !bit_test(s->tabs, cx));
    }
    s->cx = cx;
    break;
  case INPUT_CSI_CUB:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_cursorleft(sctx, n);
    break;
  case INPUT_CSI_CUD:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_cursordown(sctx, n);
    break;
  case INPUT_CSI_CUF:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_cursorright(sctx, n);
    break;
  case INPUT_CSI_CUP:
    n = input_get(ictx, 0, 1, 1);
    m = input_get(ictx, 1, 1, 1);
    if (n != -1 && m != -1)
      screen_write_cursormove(sctx, m - 1, n - 1, 1);
    break;
  case INPUT_CSI_MODSET:
    n = input_get(ictx, 0, 0, 0);
    if (n != 4)
      break;
    m = input_get(ictx, 1, 0, 0);

    /*
     * Set the extended key reporting mode as per the client
     * request, unless "extended-keys" is set to "off".
     */
    ek = options_get_number(global_options, "extended-keys");
    if (ek == 0)
      break;
    screen_write_mode_clear(sctx, EXTENDED_KEY_MODES);
    if (m == 2)
      screen_write_mode_set(sctx, MODE_KEYS_EXTENDED_2);
    else if (m == 1 || ek == 2)
      screen_write_mode_set(sctx, MODE_KEYS_EXTENDED);
    break;
  case INPUT_CSI_MODOFF:
    n = input_get(ictx, 0, 0, 0);
    if (n != 4)
      break;

    /*
     * Clear the extended key reporting mode as per the client
     * request, unless "extended-keys always" forces into mode 1.
     */
    screen_write_mode_clear(sctx,
        MODE_KEYS_EXTENDED|MODE_KEYS_EXTENDED_2);
    if (options_get_number(global_options, "extended-keys") == 2)
      screen_write_mode_set(sctx, MODE_KEYS_EXTENDED);
    break;
  case INPUT_CSI_WINOPS:
    input_csi_dispatch_winops(ictx);
    break;
  case INPUT_CSI_CUU:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_cursorup(sctx, n);
    break;
  case INPUT_CSI_CNL:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1) {
      screen_write_carriagereturn(sctx);
      screen_write_cursordown(sctx, n);
    }
    break;
  case INPUT_CSI_CPL:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1) {
      screen_write_carriagereturn(sctx);
      screen_write_cursorup(sctx, n);
    }
    break;
  case INPUT_CSI_DA:
    switch (input_get(ictx, 0, 0, 0)) {
    case -1:
      break;
    case 0:
#ifdef ENABLE_SIXEL
      input_reply(ictx, 1, "\033[?1;2;4c");
#else
      input_reply(ictx, 1, "\033[?1;2c");
#endif
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
    break;
  case INPUT_CSI_DA_TWO:
    switch (input_get(ictx, 0, 0, 0)) {
    case -1:
      break;
    case 0:
      input_reply(ictx, 1, "\033[>84;0;0c");
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
    break;
  case INPUT_CSI_ECH:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_clearcharacter(sctx, n, bg);
    break;
  case INPUT_CSI_DCH:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_deletecharacter(sctx, n, bg);
    break;
  case INPUT_CSI_DECSTBM:
    n = input_get(ictx, 0, 1, 1);
    m = input_get(ictx, 1, 1, screen_size_y(s));
    if (n != -1 && m != -1)
      screen_write_scrollregion(sctx, n - 1, m - 1);
    break;
  case INPUT_CSI_DL:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_deleteline(sctx, n, bg);
    break;
  case INPUT_CSI_DSR_PRIVATE:
    switch (input_get(ictx, 0, 0, 0)) {
    case 996:
      input_report_current_theme(ictx);
      break;
    }
    break;
  case INPUT_CSI_QUERY_PRIVATE:
    switch (input_get(ictx, 0, 0, 0)) {
    case 12: /* cursor blink: 1 = blink, 2 = steady */
      if (s->cstyle != SCREEN_CURSOR_DEFAULT ||
          s->mode & MODE_CURSOR_BLINKING_SET)
        n = (s->mode & MODE_CURSOR_BLINKING) ? 1 : 2;
      else {
        if (ictx->wp != NULL)
          oo = ictx->wp->options;
        else
          oo = global_w_options;
        p = options_get_number(oo, "cursor-style");

        /* blink for 1,3,5; steady for 0,2,4,6 */
        n = (p == 1 || p == 3 || p == 5) ? 1 : 2;
      }
      input_reply(ictx, 1, "\033[?12;%d$y", n);
      break;
    case 1004: /* focus reporting */
      n = (s->mode & MODE_FOCUSON) ? 1 : 2;
      input_reply(ictx, 1, "\033[?1004;%d$y", n);
      break;
    case 1006: /* SGR mouse */
      n = (s->mode & MODE_MOUSE_SGR) ? 1 : 2;
      input_reply(ictx, 1, "\033[?1006;%d$y", n);
      break;
    case 2004: /* bracketed paste */
      n = (s->mode & MODE_BRACKETPASTE) ? 1 : 2;
      input_reply(ictx, 1, "\033[?2004;%d$y", n);
      break;
    case 2026: /* synchronized output */
      n = (s->mode & MODE_SYNC) ? 1 : 2;
      input_reply(ictx, 1, "\033[?2026;%d$y", n);
      break;
    case 2031:
      input_reply(ictx, 1, "\033[?2031;2$y");
      break;
    }
    break;
  case INPUT_CSI_DSR:
    switch (input_get(ictx, 0, 0, 0)) {
    case -1:
      break;
    case 5:
      input_reply(ictx, 1, "\033[0n");
      break;
    case 6:
      input_reply(ictx, 1, "\033[%u;%uR", s->cy + 1,
          s->cx + 1);
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
    break;
  case INPUT_CSI_ED:
    switch (input_get(ictx, 0, 0, 0)) {
    case -1:
      break;
    case 0:
      screen_write_clearendofscreen(sctx, bg);
      break;
    case 1:
      screen_write_clearstartofscreen(sctx, bg);
      break;
    case 2:
      screen_write_clearscreen(sctx, bg);
      break;
    case 3:
      if (input_get(ictx, 1, 0, 0) == 0) {
        /*
         * Linux console extension to clear history
         * (for example before locking the screen).
         */
        screen_write_clearhistory(sctx);
      }
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
    break;
  case INPUT_CSI_EL:
    switch (input_get(ictx, 0, 0, 0)) {
    case -1:
      break;
    case 0:
      screen_write_clearendofline(sctx, bg);
      break;
    case 1:
      screen_write_clearstartofline(sctx, bg);
      break;
    case 2:
      screen_write_clearline(sctx, bg);
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
    break;
  case INPUT_CSI_HPA:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_cursormove(sctx, n - 1, -1, 1);
    break;
  case INPUT_CSI_ICH:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_insertcharacter(sctx, n, bg);
    break;
  case INPUT_CSI_IL:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_insertline(sctx, n, bg);
    break;
  case INPUT_CSI_REP:
    n = input_get(ictx, 0, 1, 1);
    if (n == -1)
      break;

    m = screen_size_x(s) - s->cx;
    if (n > m)
      n = m;

    if (~ictx->flags & INPUT_LAST)
      break;

    set = ictx->cell.set == 0 ? ictx->cell.g0set : ictx->cell.g1set;
    if (set == 1)
      ictx->cell.cell.attr |= GRID_ATTR_CHARSET;
    else
      ictx->cell.cell.attr &= ~GRID_ATTR_CHARSET;
    utf8_copy(&ictx->cell.cell.data, &ictx->last);
    for (i = 0; i < n; i++)
      screen_write_collect_add(sctx, &ictx->cell.cell);
    break;
  case INPUT_CSI_RCP:
    input_restore_state(ictx);
    break;
  case INPUT_CSI_RM:
    input_csi_dispatch_rm(ictx);
    break;
  case INPUT_CSI_RM_PRIVATE:
    input_csi_dispatch_rm_private(ictx);
    break;
  case INPUT_CSI_SCP:
    input_save_state(ictx);
    break;
  case INPUT_CSI_SGR:
    input_csi_dispatch_sgr(ictx);
    break;
  case INPUT_CSI_SM:
    input_csi_dispatch_sm(ictx);
    break;
  case INPUT_CSI_SM_PRIVATE:
    input_csi_dispatch_sm_private(ictx);
    break;
  case INPUT_CSI_SM_GRAPHICS:
    input_csi_dispatch_sm_graphics(ictx);
    break;
  case INPUT_CSI_SU:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_scrollup(sctx, n, bg);
    break;
  case INPUT_CSI_SD:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_scrolldown(sctx, n, bg);
    break;
  case INPUT_CSI_TBC:
    switch (input_get(ictx, 0, 0, 0)) {
    case -1:
      break;
    case 0:
      if (s->cx < screen_size_x(s))
        bit_clear(s->tabs, s->cx);
      break;
    case 3:
      bit_nclear(s->tabs, 0, screen_size_x(s) - 1);
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
    break;
  case INPUT_CSI_VPA:
    n = input_get(ictx, 0, 1, 1);
    if (n != -1)
      screen_write_cursormove(sctx, -1, n - 1, 1);
    break;
  case INPUT_CSI_DECSCUSR:
    n = input_get(ictx, 0, 0, 0);
    if (n == -1)
      break;
    screen_set_cursor_style(n, &s->cstyle, &s->mode);
    if (n == 0) {
      /* Go back to default blinking state. */
      screen_write_mode_clear(sctx, MODE_CURSOR_BLINKING_SET);
    }
    break;
  case INPUT_CSI_XDA:
    n = input_get(ictx, 0, 0, 0);
    if (n == 0) {
      input_reply(ictx, 1, "\033P>|tmux %s\033\\",
          getversion());
    }
    break;

  }

  ictx->flags &= ~INPUT_LAST;
  return (0);
}

/* Handle CSI RM. */
static void
input_csi_dispatch_rm(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  u_int      i;

  for (i = 0; i < ictx->param_list_len; i++) {
    switch (input_get(ictx, i, 0, -1)) {
    case -1:
      break;
    case 4:   /* IRM */
      screen_write_mode_clear(sctx, MODE_INSERT);
      break;
    case 34:
      screen_write_mode_set(sctx, MODE_CURSOR_VERY_VISIBLE);
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
  }
}

/* Handle CSI private RM. */
static void
input_csi_dispatch_rm_private(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  struct grid_cell  *gc = &ictx->cell.cell;
  u_int      i;

  for (i = 0; i < ictx->param_list_len; i++) {
    switch (input_get(ictx, i, 0, -1)) {
    case -1:
      break;
    case 1:   /* DECCKM */
      screen_write_mode_clear(sctx, MODE_KCURSOR);
      break;
    case 3:   /* DECCOLM */
      screen_write_cursormove(sctx, 0, 0, 1);
      screen_write_clearscreen(sctx, gc->bg);
      break;
    case 6:   /* DECOM */
      screen_write_mode_clear(sctx, MODE_ORIGIN);
      screen_write_cursormove(sctx, 0, 0, 1);
      break;
    case 7:   /* DECAWM */
      screen_write_mode_clear(sctx, MODE_WRAP);
      break;
    case 12:
      screen_write_mode_clear(sctx, MODE_CURSOR_BLINKING);
      screen_write_mode_set(sctx, MODE_CURSOR_BLINKING_SET);
      break;
    case 25:  /* TCEM */
      screen_write_mode_clear(sctx, MODE_CURSOR);
      break;
    case 1000:
    case 1001:
    case 1002:
    case 1003:
      screen_write_mode_clear(sctx, ALL_MOUSE_MODES);
      break;
    case 1004:
      screen_write_mode_clear(sctx, MODE_FOCUSON);
      break;
    case 1005:
      screen_write_mode_clear(sctx, MODE_MOUSE_UTF8);
      break;
    case 1006:
      screen_write_mode_clear(sctx, MODE_MOUSE_SGR);
      break;
    case 47:
    case 1047:
      screen_write_alternateoff(sctx, gc, 0);
      break;
    case 1049:
      screen_write_alternateoff(sctx, gc, 1);
      break;
    case 2004:
      screen_write_mode_clear(sctx, MODE_BRACKETPASTE);
      break;
    case 2031:
      screen_write_mode_clear(sctx, MODE_THEME_UPDATES);
      if (ictx->wp != NULL)
        ictx->wp->flags &= ~PANE_THEMECHANGED;
      break;
    case 2026:  /* synchronized output */
      screen_write_stop_sync(ictx->wp);
      if (ictx->wp != NULL)
        ictx->wp->flags |= PANE_REDRAW;
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
  }
}

/* Handle CSI SM. */
static void
input_csi_dispatch_sm(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  u_int      i;

  for (i = 0; i < ictx->param_list_len; i++) {
    switch (input_get(ictx, i, 0, -1)) {
    case -1:
      break;
    case 4:   /* IRM */
      screen_write_mode_set(sctx, MODE_INSERT);
      break;
    case 34:
      screen_write_mode_clear(sctx, MODE_CURSOR_VERY_VISIBLE);
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
  }
}

/* Handle CSI private SM. */
static void
input_csi_dispatch_sm_private(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  struct grid_cell  *gc = &ictx->cell.cell;
  u_int      i;

  for (i = 0; i < ictx->param_list_len; i++) {
    switch (input_get(ictx, i, 0, -1)) {
    case -1:
      break;
    case 1:   /* DECCKM */
      screen_write_mode_set(sctx, MODE_KCURSOR);
      break;
    case 3:   /* DECCOLM */
      screen_write_cursormove(sctx, 0, 0, 1);
      screen_write_clearscreen(sctx, ictx->cell.cell.bg);
      break;
    case 6:   /* DECOM */
      screen_write_mode_set(sctx, MODE_ORIGIN);
      screen_write_cursormove(sctx, 0, 0, 1);
      break;
    case 7:   /* DECAWM */
      screen_write_mode_set(sctx, MODE_WRAP);
      break;
    case 12:
      screen_write_mode_set(sctx, MODE_CURSOR_BLINKING);
      screen_write_mode_set(sctx, MODE_CURSOR_BLINKING_SET);
      break;
    case 25:  /* TCEM */
      screen_write_mode_set(sctx, MODE_CURSOR);
      break;
    case 1000:
      screen_write_mode_clear(sctx, ALL_MOUSE_MODES);
      screen_write_mode_set(sctx, MODE_MOUSE_STANDARD);
      break;
    case 1002:
      screen_write_mode_clear(sctx, ALL_MOUSE_MODES);
      screen_write_mode_set(sctx, MODE_MOUSE_BUTTON);
      break;
    case 1003:
      screen_write_mode_clear(sctx, ALL_MOUSE_MODES);
      screen_write_mode_set(sctx, MODE_MOUSE_ALL);
      break;
    case 1004:
      screen_write_mode_set(sctx, MODE_FOCUSON);
      break;
    case 1005:
      screen_write_mode_set(sctx, MODE_MOUSE_UTF8);
      break;
    case 1006:
      screen_write_mode_set(sctx, MODE_MOUSE_SGR);
      break;
    case 47:
    case 1047:
      screen_write_alternateon(sctx, gc, 0);
      break;
    case 1049:
      screen_write_alternateon(sctx, gc, 1);
      break;
    case 2004:
      screen_write_mode_set(sctx, MODE_BRACKETPASTE);
      break;
    case 2031:
      screen_write_mode_set(sctx, MODE_THEME_UPDATES);
      if (ictx->wp != NULL) {
        ictx->wp->last_theme = window_pane_get_theme(ictx->wp);
        ictx->wp->flags &= ~PANE_THEMECHANGED;
      }
      break;
    case 2026:  /* synchronized output */
      screen_write_start_sync(ictx->wp);
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
  }
}

/* Handle CSI graphics SM. */
static void
input_csi_dispatch_sm_graphics(__unused struct input_ctx *ictx)
{
#ifdef ENABLE_SIXEL
  int n, m, o;

  if (ictx->param_list_len > 3)
    return;
  n = input_get(ictx, 0, 0, 0);
  m = input_get(ictx, 1, 0, 0);
  o = input_get(ictx, 2, 0, 0);

  if (n == 1 && (m == 1 || m == 2 || m == 4)) {
    input_reply(ictx, 1, "\033[?%d;0;%uS", n,
        SIXEL_COLOUR_REGISTERS);
  } else
    input_reply(ictx, 1, "\033[?%d;3;%dS", n, o);
#endif
}

/* Handle CSI window operations. */
static void
input_csi_dispatch_winops(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  struct screen   *s = sctx->s;
  struct window_pane  *wp = ictx->wp;
  struct window   *w = NULL;
  u_int      x = screen_size_x(s), y = screen_size_y(s);
  int      n, m;

  if (wp != NULL)
    w = wp->window;

  m = 0;
  while ((n = input_get(ictx, m, 0, -1)) != -1) {
    switch (n) {
    case 1:
    case 2:
    case 5:
    case 6:
    case 7:
    case 11:
    case 13:
    case 20:
    case 21:
    case 24:
      break;
    case 3:
    case 4:
    case 8:
      m++;
      if (input_get(ictx, m, 0, -1) == -1)
        return;
      /* FALLTHROUGH */
    case 9:
    case 10:
      m++;
      if (input_get(ictx, m, 0, -1) == -1)
        return;
      break;
    case 14:
      if (w == NULL)
        break;
      input_reply(ictx, 1, "\033[4;%u;%ut", y * w->ypixel,
          x * w->xpixel);
      break;
    case 15:
      if (w == NULL)
        break;
      input_reply(ictx, 1, "\033[5;%u;%ut", y * w->ypixel,
          x * w->xpixel);
      break;
    case 16:
      if (w == NULL)
        break;
      input_reply(ictx, 1, "\033[6;%u;%ut", w->ypixel,
          w->xpixel);
      break;
    case 18:
      input_reply(ictx, 1, "\033[8;%u;%ut", y, x);
      break;
    case 19:
      input_reply(ictx, 1, "\033[9;%u;%ut", y, x);
      break;
    case 22:
      m++;
      switch (input_get(ictx, m, 0, -1)) {
      case -1:
        return;
      case 0:
      case 2:
        screen_push_title(sctx->s);
        break;
      }
      break;
    case 23:
      m++;
      switch (input_get(ictx, m, 0, -1)) {
      case -1:
        return;
      case 0:
      case 2:
        screen_pop_title(sctx->s);
        if (wp == NULL)
          break;
        notify_pane("pane-title-changed", wp);
        server_redraw_window_borders(w);
        server_status_window(w);
        break;
      }
      break;
    default:
      log_debug("%s: unknown '%c'", __func__, ictx->ch);
      break;
    }
    m++;
  }
}

/* Helper for 256 colour SGR. */
static int
input_csi_dispatch_sgr_256_do(struct input_ctx *ictx, int fgbg, int c)
{
  struct grid_cell  *gc = &ictx->cell.cell;

  if (c == -1 || c > 255) {
    if (fgbg == 38)
      gc->fg = 8;
    else if (fgbg == 48)
      gc->bg = 8;
  } else {
    if (fgbg == 38)
      gc->fg = c | COLOUR_FLAG_256;
    else if (fgbg == 48)
      gc->bg = c | COLOUR_FLAG_256;
    else if (fgbg == 58)
      gc->us = c | COLOUR_FLAG_256;
  }
  return (1);
}

/* Handle CSI SGR for 256 colours. */
static void
input_csi_dispatch_sgr_256(struct input_ctx *ictx, int fgbg, u_int *i)
{
  int c;

  c = input_get(ictx, (*i) + 1, 0, -1);
  if (input_csi_dispatch_sgr_256_do(ictx, fgbg, c))
    (*i)++;
}

/* Helper for RGB colour SGR. */
static int
input_csi_dispatch_sgr_rgb_do(struct input_ctx *ictx, int fgbg, int r, int g,
    int b)
{
  struct grid_cell  *gc = &ictx->cell.cell;

  if (r == -1 || r > 255)
    return (0);
  if (g == -1 || g > 255)
    return (0);
  if (b == -1 || b > 255)
    return (0);

  if (fgbg == 38)
    gc->fg = colour_join_rgb(r, g, b);
  else if (fgbg == 48)
    gc->bg = colour_join_rgb(r, g, b);
  else if (fgbg == 58)
    gc->us = colour_join_rgb(r, g, b);
  return (1);
}

/* Handle CSI SGR for RGB colours. */
static void
input_csi_dispatch_sgr_rgb(struct input_ctx *ictx, int fgbg, u_int *i)
{
  int r, g, b;

  r = input_get(ictx, (*i) + 1, 0, -1);
  g = input_get(ictx, (*i) + 2, 0, -1);
  b = input_get(ictx, (*i) + 3, 0, -1);
  if (input_csi_dispatch_sgr_rgb_do(ictx, fgbg, r, g, b))
    (*i) += 3;
}

/* Handle CSI SGR with a ISO parameter. */
static void
input_csi_dispatch_sgr_colon(struct input_ctx *ictx, u_int i)
{
  struct grid_cell  *gc = &ictx->cell.cell;
  char      *s = ictx->param_list[i].str, *copy, *ptr, *out;
  int      p[8];
  u_int      n;
  const char    *errstr;

  for (n = 0; n < nitems(p); n++)
    p[n] = -1;
  n = 0;

  ptr = copy = xstrdup(s);
  while ((out = strsep(&ptr, ":")) != NULL) {
    if (*out != '\0') {
      p[n++] = strtonum(out, 0, INT_MAX, &errstr);
      if (errstr != NULL || n == nitems(p)) {
        free(copy);
        return;
      }
    } else {
      n++;
      if (n == nitems(p)) {
        free(copy);
        return;
      }
    }
    log_debug("%s: %u = %d", __func__, n - 1, p[n - 1]);
  }
  free(copy);

  if (n == 0)
    return;
  if (p[0] == 4) {
    if (n != 2)
      return;
    switch (p[1]) {
    case 0:
      gc->attr &= ~GRID_ATTR_ALL_UNDERSCORE;
      break;
    case 1:
      gc->attr &= ~GRID_ATTR_ALL_UNDERSCORE;
      gc->attr |= GRID_ATTR_UNDERSCORE;
      break;
    case 2:
      gc->attr &= ~GRID_ATTR_ALL_UNDERSCORE;
      gc->attr |= GRID_ATTR_UNDERSCORE_2;
      break;
    case 3:
      gc->attr &= ~GRID_ATTR_ALL_UNDERSCORE;
      gc->attr |= GRID_ATTR_UNDERSCORE_3;
      break;
    case 4:
      gc->attr &= ~GRID_ATTR_ALL_UNDERSCORE;
      gc->attr |= GRID_ATTR_UNDERSCORE_4;
      break;
    case 5:
      gc->attr &= ~GRID_ATTR_ALL_UNDERSCORE;
      gc->attr |= GRID_ATTR_UNDERSCORE_5;
      break;
    }
    return;
  }
  if (n < 2 || (p[0] != 38 && p[0] != 48 && p[0] != 58))
    return;
  switch (p[1]) {
  case 2:
    if (n < 3)
      break;
    if (n == 5)
      i = 2;
    else
      i = 3;
    if (n < i + 3)
      break;
    input_csi_dispatch_sgr_rgb_do(ictx, p[0], p[i], p[i + 1],
        p[i + 2]);
    break;
  case 5:
    if (n < 3)
      break;
    input_csi_dispatch_sgr_256_do(ictx, p[0], p[2]);
    break;
  }
}

/* Handle CSI SGR. */
static void
input_csi_dispatch_sgr(struct input_ctx *ictx)
{
  struct grid_cell  *gc = &ictx->cell.cell;
  u_int      i, link;
  int      n;

  if (ictx->param_list_len == 0) {
    memcpy(gc, &grid_default_cell, sizeof *gc);
    return;
  }

  for (i = 0; i < ictx->param_list_len; i++) {
    if (ictx->param_list[i].type == INPUT_STRING) {
      input_csi_dispatch_sgr_colon(ictx, i);
      continue;
    }
    n = input_get(ictx, i, 0, 0);
    if (n == -1)
      continue;

    if (n == 38 || n == 48 || n == 58) {
      i++;
      switch (input_get(ictx, i, 0, -1)) {
      case 2:
        input_csi_dispatch_sgr_rgb(ictx, n, &i);
        break;
      case 5:
        input_csi_dispatch_sgr_256(ictx, n, &i);
        break;
      }
      continue;
    }

    switch (n) {
    case 0:
      link = gc->link;
      memcpy(gc, &grid_default_cell, sizeof *gc);
      gc->link = link;
      break;
    case 1:
      gc->attr |= GRID_ATTR_BRIGHT;
      break;
    case 2:
      gc->attr |= GRID_ATTR_DIM;
      break;
    case 3:
      gc->attr |= GRID_ATTR_ITALICS;
      break;
    case 4:
      gc->attr &= ~GRID_ATTR_ALL_UNDERSCORE;
      gc->attr |= GRID_ATTR_UNDERSCORE;
      break;
    case 5:
    case 6:
      gc->attr |= GRID_ATTR_BLINK;
      break;
    case 7:
      gc->attr |= GRID_ATTR_REVERSE;
      break;
    case 8:
      gc->attr |= GRID_ATTR_HIDDEN;
      break;
    case 9:
      gc->attr |= GRID_ATTR_STRIKETHROUGH;
      break;
    case 21:
      gc->attr &= ~GRID_ATTR_ALL_UNDERSCORE;
      gc->attr |= GRID_ATTR_UNDERSCORE_2;
      break;
    case 22:
      gc->attr &= ~(GRID_ATTR_BRIGHT|GRID_ATTR_DIM);
      break;
    case 23:
      gc->attr &= ~GRID_ATTR_ITALICS;
      break;
    case 24:
      gc->attr &= ~GRID_ATTR_ALL_UNDERSCORE;
      break;
    case 25:
      gc->attr &= ~GRID_ATTR_BLINK;
      break;
    case 27:
      gc->attr &= ~GRID_ATTR_REVERSE;
      break;
    case 28:
      gc->attr &= ~GRID_ATTR_HIDDEN;
      break;
    case 29:
      gc->attr &= ~GRID_ATTR_STRIKETHROUGH;
      break;
    case 30:
    case 31:
    case 32:
    case 33:
    case 34:
    case 35:
    case 36:
    case 37:
      gc->fg = n - 30;
      break;
    case 39:
      gc->fg = 8;
      break;
    case 40:
    case 41:
    case 42:
    case 43:
    case 44:
    case 45:
    case 46:
    case 47:
      gc->bg = n - 40;
      break;
    case 49:
      gc->bg = 8;
      break;
    case 53:
      gc->attr |= GRID_ATTR_OVERLINE;
      break;
    case 55:
      gc->attr &= ~GRID_ATTR_OVERLINE;
      break;
    case 59:
      gc->us = 8;
      break;
    case 90:
    case 91:
    case 92:
    case 93:
    case 94:
    case 95:
    case 96:
    case 97:
      gc->fg = n;
      break;
    case 100:
    case 101:
    case 102:
    case 103:
    case 104:
    case 105:
    case 106:
    case 107:
      gc->bg = n - 10;
      break;
    }
  }
}

/* End of input with BEL. */
static int
input_end_bel(struct input_ctx *ictx)
{
  log_debug("%s", __func__);

  ictx->input_end = INPUT_END_BEL;

  return (0);
}

/* DCS string started. */
static void
input_enter_dcs(struct input_ctx *ictx)
{
  log_debug("%s", __func__);

  input_clear(ictx);
  input_start_ground_timer(ictx);
  ictx->flags &= ~INPUT_LAST;
}

/* Handle DECRQSS query. */
static int
input_handle_decrqss(struct input_ctx *ictx)
{
  struct window_pane  *wp = ictx->wp;
  struct options    *oo;
  struct screen_write_ctx *sctx = &ictx->ctx;
  u_char      *buf = ictx->input_buf;
  size_t       len = ictx->input_len;
  struct screen   *s = sctx->s;
  int      ps, opt_ps, blinking;

  if (len < 3 || buf[1] != ' ' || buf[2] != 'q')
    goto not_recognized;

  /*
   * Cursor style query: DCS $ q SP q
   * Reply: DCS 1 $ r SP q <Ps> SP q ST
   */
  if (s->cstyle == SCREEN_CURSOR_BLOCK ||
      s->cstyle == SCREEN_CURSOR_UNDERLINE ||
      s->cstyle == SCREEN_CURSOR_BAR) {
    blinking = (s->mode & MODE_CURSOR_BLINKING) != 0;
    switch (s->cstyle) {
    case SCREEN_CURSOR_BLOCK:
      ps = blinking ? 1 : 2;
      break;
    case SCREEN_CURSOR_UNDERLINE:
      ps = blinking ? 3 : 4;
      break;
    case SCREEN_CURSOR_BAR:
      ps = blinking ? 5 : 6;
      break;
    default:
      ps = 0;
      break;
    }
  } else {
    /*
     * No explicit runtime style: fall back to the configured
     * cursor-style option (integer Ps 0..6). Pane options inherit.
     */
    if (wp != NULL)
      oo = wp->options;
    else
      oo = global_w_options;
    opt_ps = options_get_number(oo, "cursor-style");

    /* Sanity clamp: valid Ps are 0..6 per DECSCUSR. */
    if (opt_ps < 0 || opt_ps > 6)
      opt_ps = 0;
    ps = opt_ps;
  }

  log_debug("%s: DECRQSS cursor -> Ps=%d (cstyle=%d mode=%#x)", __func__,
      ps, s->cstyle, s->mode);

  input_reply(ictx, 1, "\033P1$r q%d q\033\\", ps);
  return (0);

not_recognized:
  /* Unrecognized DECRQSS: send DCS 0 $ r Pt ST. */
  input_reply(ictx, 1, "\033P0$r\033\\");
  return (0);
}

/* DCS terminator (ST) received. */
static int
input_dcs_dispatch(struct input_ctx *ictx)
{
  struct window_pane  *wp = ictx->wp;
  struct options    *oo;
  struct screen_write_ctx *sctx = &ictx->ctx;
  u_char      *buf = ictx->input_buf;
  size_t       len = ictx->input_len;
  const char     prefix[] = "tmux;";
  const u_int    prefixlen = (sizeof prefix) - 1;
  long long    allow_passthrough = 0;
#ifdef ENABLE_SIXEL
  struct window   *w;
  struct sixel_image  *si;
  int      p2;
#endif

  if (wp == NULL)
    oo = global_w_options;
  else
    oo = wp->options;

  if (ictx->flags & INPUT_DISCARD) {
    log_debug("%s: %zu bytes (discard)", __func__, len);
    return (0);
  }

#ifdef ENABLE_SIXEL
  if (wp != NULL && buf[0] == 'q' && ictx->interm_len == 0) {
    w = wp->window;
    if (input_split(ictx) != 0)
      return (0);
    p2 = input_get(ictx, 1, 0, 0);
    if (p2 == -1)
      p2 = 0;
    si = sixel_parse(buf, len, p2, w->xpixel, w->ypixel);
    if (si != NULL)
      screen_write_sixelimage(sctx, si, ictx->cell.cell.bg);
  }
#endif

  /* DCS sequences with intermediate byte '$' (includes DECRQSS). */
  if (ictx->interm_len == 1 && ictx->interm_buf[0] == '$') {
    /* DECRQSS is DCS $ q Pt ST. */
    if (len >= 1 && buf[0] == 'q')
      return (input_handle_decrqss(ictx));

    /*
     * Not DECRQSS. DCS '$' is currently only used by DECRQSS, but
     * leave other '$' DCS (if any appear in future) to existing
     * handlers.
     */
  }

  allow_passthrough = options_get_number(oo, "allow-passthrough");
  if (!allow_passthrough)
    return (0);
  log_debug("%s: \"%s\"", __func__, buf);

  if (len >= prefixlen && strncmp(buf, prefix, prefixlen) == 0) {
    screen_write_rawstring(sctx, buf + prefixlen, len - prefixlen,
        allow_passthrough == 2);
  }

  return (0);
}

/* OSC string started. */
static void
input_enter_osc(struct input_ctx *ictx)
{
  log_debug("%s", __func__);

  input_clear(ictx);
  input_start_ground_timer(ictx);
  ictx->flags &= ~INPUT_LAST;
}

/* OSC terminator (ST) received. */
static void
input_exit_osc(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  struct window_pane  *wp = ictx->wp;
  u_char      *p = ictx->input_buf;
  u_int      option;

  if (ictx->flags & INPUT_DISCARD)
    return;
  if (ictx->input_len < 1 || *p < '0' || *p > '9')
    return;

  log_debug("%s: \"%s\" (end %s)", __func__, p,
      ictx->input_end == INPUT_END_ST ? "ST" : "BEL");

  option = 0;
  while (*p >= '0' && *p <= '9')
    option = option * 10 + *p++ - '0';
  if (*p != ';' && *p != '\0')
    return;
  if (*p == ';')
    p++;

  switch (option) {
  case 0:
  case 2:
    if (wp != NULL &&
        options_get_number(wp->options, "allow-set-title") &&
        screen_set_title(sctx->s, p)) {
      notify_pane("pane-title-changed", wp);
      server_redraw_window_borders(wp->window);
      server_status_window(wp->window);
    }
    break;
  case 4:
    input_osc_4(ictx, p);
    break;
  case 7:
    if (screen_set_path(sctx->s, p) && wp != NULL) {
      server_redraw_window_borders(wp->window);
      server_status_window(wp->window);
    }
    break;
  case 8:
    input_osc_8(ictx, p);
    break;
  case 9:
    input_osc_9(ictx, p);
    break;
  case 10:
    input_osc_10(ictx, p);
    break;
  case 11:
    input_osc_11(ictx, p);
    break;
  case 12:
    input_osc_12(ictx, p);
    break;
  case 52:
    input_osc_52(ictx, p);
    break;
  case 104:
    input_osc_104(ictx, p);
    break;
  case 110:
    input_osc_110(ictx, p);
    break;
  case 111:
    input_osc_111(ictx, p);
    break;
  case 112:
    input_osc_112(ictx, p);
    break;
  case 133:
    input_osc_133(ictx, p);
    break;
  default:
    log_debug("%s: unknown '%u'", __func__, option);
    break;
  }
}

/* APC string started. */
static void
input_enter_apc(struct input_ctx *ictx)
{
  log_debug("%s", __func__);

  input_clear(ictx);
  input_start_ground_timer(ictx);
  ictx->flags &= ~INPUT_LAST;
}

/* APC terminator (ST) received. */
static void
input_exit_apc(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  struct window_pane  *wp = ictx->wp;

  if (ictx->flags & INPUT_DISCARD)
    return;
  log_debug("%s: \"%s\"", __func__, ictx->input_buf);

  if (wp != NULL &&
      options_get_number(wp->options, "allow-set-title") &&
      screen_set_title(sctx->s, ictx->input_buf)) {
    notify_pane("pane-title-changed", wp);
    server_redraw_window_borders(wp->window);
    server_status_window(wp->window);
  }
}

/* Rename string started. */
static void
input_enter_rename(struct input_ctx *ictx)
{
  log_debug("%s", __func__);

  input_clear(ictx);
  input_start_ground_timer(ictx);
  ictx->flags &= ~INPUT_LAST;
}

/* Rename terminator (ST) received. */
static void
input_exit_rename(struct input_ctx *ictx)
{
  struct window_pane  *wp = ictx->wp;
  struct window   *w;
  struct options_entry  *o;

  if (wp == NULL)
    return;
  if (ictx->flags & INPUT_DISCARD)
    return;
  if (!options_get_number(ictx->wp->options, "allow-rename"))
    return;
  log_debug("%s: \"%s\"", __func__, ictx->input_buf);

  if (!utf8_isvalid(ictx->input_buf))
    return;
  w = wp->window;

  if (ictx->input_len == 0) {
    o = options_get_only(w->options, "automatic-rename");
    if (o != NULL)
      options_remove_or_default(o, -1, NULL);
    if (!options_get_number(w->options, "automatic-rename"))
      window_set_name(w, "");
  } else {
    options_set_number(w->options, "automatic-rename", 0);
    window_set_name(w, ictx->input_buf);
  }
  server_redraw_window_borders(w);
  server_status_window(w);
}

/* Open UTF-8 character. */
static int
input_top_bit_set(struct input_ctx *ictx)
{
  struct screen_write_ctx *sctx = &ictx->ctx;
  struct utf8_data  *ud = &ictx->utf8data;

  ictx->flags &= ~INPUT_LAST;

  if (!ictx->utf8started) {
    ictx->utf8started = 1;
    if (utf8_open(ud, ictx->ch) != UTF8_MORE)
      input_stop_utf8(ictx);
    return (0);
  }

  switch (utf8_append(ud, ictx->ch)) {
  case UTF8_MORE:
    return (0);
  case UTF8_ERROR:
    input_stop_utf8(ictx);
    return (0);
  case UTF8_DONE:
    break;
  }
  ictx->utf8started = 0;

  log_debug("%s %hhu '%*s' (width %hhu)", __func__, ud->size,
      (int)ud->size, ud->data, ud->width);

  utf8_copy(&ictx->cell.cell.data, ud);
  screen_write_collect_add(sctx, &ictx->cell.cell);

  utf8_copy(&ictx->last, &ictx->cell.cell.data);
  ictx->flags |= INPUT_LAST;

  return (0);
}

/* Reply to a colour request. */
static void
input_osc_colour_reply(struct input_ctx *ictx, int add, u_int n, int idx, int c,
    enum input_end_type end_type)
{
  u_char     r, g, b;
  const char  *end;

  if (c != -1)
    c = colour_force_rgb(c);
  if (c == -1)
      return;
  colour_split_rgb(c, &r, &g, &b);

  if (end_type == INPUT_END_BEL)
    end = "\007";
  else
    end = "\033\\";

  if (n == 4) {
    input_reply(ictx, add,
        "\033]%u;%d;rgb:%02hhx%02hhx/%02hhx%02hhx/%02hhx%02hhx%s",
        n, idx, r, r, g, g, b, b, end);
  } else {
    input_reply(ictx, add,
        "\033]%u;rgb:%02hhx%02hhx/%02hhx%02hhx/%02hhx%02hhx%s",
        n, r, r, g, g, b, b, end);
  }
}

/* Handle the OSC 4 sequence for setting (multiple) palette entries. */
static void
input_osc_4(struct input_ctx *ictx, const char *p)
{
  char      *copy, *s, *next = NULL;
  long       idx;
  int      c, bad = 0, redraw = 0;
  struct colour_palette *palette = ictx->palette;

  copy = s = xstrdup(p);
  while (s != NULL && *s != '\0') {
    idx = strtol(s, &next, 10);
    if (*next++ != ';') {
      bad = 1;
      break;
    }
    if (idx < 0 || idx >= 256) {
      bad = 1;
      break;
    }

    s = strsep(&next, ";");
    if (strcmp(s, "?") == 0) {
      c = colour_palette_get(palette, idx|COLOUR_FLAG_256);
      if (c != -1) {
        input_osc_colour_reply(ictx, 1, 4, idx, c,
            ictx->input_end);
        s = next;
        continue;
      }
      input_add_request(ictx, INPUT_REQUEST_PALETTE, idx);
      s = next;
      continue;
    }
    if ((c = colour_parseX11(s)) == -1) {
      s = next;
      continue;
    }
    if (colour_palette_set(palette, idx, c))
      redraw = 1;
    s = next;
  }
  if (bad)
    log_debug("bad OSC 4: %s", p);
  if (redraw)
    screen_write_fullredraw(&ictx->ctx);
  free(copy);
}

/* Handle the OSC 8 sequence for embedding hyperlinks. */
static void
input_osc_8(struct input_ctx *ictx, const char *p)
{
  struct hyperlinks *hl = ictx->ctx.s->hyperlinks;
  struct grid_cell  *gc = &ictx->cell.cell;
  const char    *start, *end, *uri;
  char      *id = NULL;

  for (start = p; (end = strpbrk(start, ":;")) != NULL; start = end + 1) {
    if (end - start >= 4 && strncmp(start, "id=", 3) == 0) {
      if (id != NULL)
        goto bad;
      id = xstrndup(start + 3, end - start - 3);
    }

    /* The first ; is the end of parameters and start of the URI. */
    if (*end == ';')
      break;
  }
  if (end == NULL || *end != ';')
    goto bad;
  uri = end + 1;
  if (*uri == '\0') {
    gc->link = 0;
    free(id);
    return;
  }
  gc->link = hyperlinks_put(hl, uri, id);
  if (id == NULL)
    log_debug("hyperlink (anonymous) %s = %u", uri, gc->link);
  else
    log_debug("hyperlink (id=%s) %s = %u", id, uri, gc->link);
  free(id);
  return;

bad:
  log_debug("bad OSC 8 %s", p);
  free(id);
}

/* Helper to handle setting the progress bar and redrawing. */
static void
input_set_progress_bar(struct input_ctx *ictx, enum progress_bar_state state,
    int p)
{
  screen_set_progress_bar(ictx->ctx.s, state, p);
  if (ictx->wp != NULL) {
    server_redraw_window_borders(ictx->wp->window);
    server_status_window(ictx->wp->window);
  }
}

/* Handle the OSC 9;4 sequence for progress bars. */
static void
input_osc_9(struct input_ctx *ictx, const char *p)
{
  const char    *pb = p;
  enum progress_bar_state  state;
  int      progress = 0;

  if (*pb++ != '4')
    return;
  if (*pb == '\0' || (*pb == ';' && pb[1] == '\0'))
    return;

  if (*pb++ != ';')
    return;
  if (*pb < '0' || *pb > '4')
    goto bad;
  state = *pb++ - '0';

  if (*pb == '\0' || (*pb == ';' && pb[1] == '\0')) {
    input_set_progress_bar(ictx, state, -1);
    return;
  }

  if (*pb++ != ';')
    goto bad;
  while (*pb >= '0' && *pb <= '9') {
    if (progress > 100)
      goto bad;
    progress = progress * 10 + *pb++ - '0';
  }
  if (*pb != '\0' || progress < 0 || progress > 100)
    goto bad;
  input_set_progress_bar(ictx, state, progress);
  return;

bad:
  log_debug("bad OSC 9;4 %s", p);
}

/* Handle the OSC 10 sequence for setting and querying foreground colour. */
static void
input_osc_10(struct input_ctx *ictx, const char *p)
{
  struct window_pane  *wp = ictx->wp;
  struct grid_cell   defaults;
  int      c;

  if (strcmp(p, "?") == 0) {
    if (wp == NULL)
      return;
    c = window_pane_get_fg_control_client(wp);
    if (c == -1) {
      tty_default_colours(&defaults, wp);
      if (COLOUR_DEFAULT(defaults.fg))
        c = window_pane_get_fg(wp);
      else
        c = defaults.fg;
    }
    input_osc_colour_reply(ictx, 1, 10, 0, c, ictx->input_end);
    return;
  }

  if ((c = colour_parseX11(p)) == -1) {
    log_debug("bad OSC 10: %s", p);
    return;
  }
  if (ictx->palette != NULL) {
    ictx->palette->fg = c;
    if (wp != NULL)
      wp->flags |= PANE_STYLECHANGED;
    screen_write_fullredraw(&ictx->ctx);
  }
}

/* Handle the OSC 110 sequence for resetting foreground colour. */
static void
input_osc_110(struct input_ctx *ictx, const char *p)
{
  struct window_pane  *wp = ictx->wp;

  if (*p != '\0')
    return;
  if (ictx->palette != NULL) {
    ictx->palette->fg = 8;
    if (wp != NULL)
      wp->flags |= PANE_STYLECHANGED;
    screen_write_fullredraw(&ictx->ctx);
  }
}

/* Handle the OSC 11 sequence for setting and querying background colour. */
static void
input_osc_11(struct input_ctx *ictx, const char *p)
{
  struct window_pane  *wp = ictx->wp;
  int      c;

  if (strcmp(p, "?") == 0) {
    if (wp == NULL)
      return;
    c = window_pane_get_bg(wp);
    input_osc_colour_reply(ictx, 1, 11, 0, c, ictx->input_end);
    return;
  }

  if ((c = colour_parseX11(p)) == -1) {
    log_debug("bad OSC 11: %s", p);
    return;
  }
  if (ictx->palette != NULL) {
    ictx->palette->bg = c;
    if (wp != NULL)
      wp->flags |= (PANE_STYLECHANGED|PANE_THEMECHANGED);
    screen_write_fullredraw(&ictx->ctx);
  }
}

/* Handle the OSC 111 sequence for resetting background colour. */
static void
input_osc_111(struct input_ctx *ictx, const char *p)
{
  struct window_pane  *wp = ictx->wp;

  if (*p != '\0')
    return;
  if (ictx->palette != NULL) {
    ictx->palette->bg = 8;
    if (wp != NULL)
      wp->flags |= (PANE_STYLECHANGED|PANE_THEMECHANGED);
    screen_write_fullredraw(&ictx->ctx);
  }
}

/* Handle the OSC 12 sequence for setting and querying cursor colour. */
static void
input_osc_12(struct input_ctx *ictx, const char *p)
{
  struct window_pane  *wp = ictx->wp;
  int      c;

  if (strcmp(p, "?") == 0) {
    if (wp != NULL) {
      c = ictx->ctx.s->ccolour;
      if (c == -1)
        c = ictx->ctx.s->default_ccolour;
      input_osc_colour_reply(ictx, 1, 12, 0, c, ictx->input_end);
    }
    return;
  }

  if ((c = colour_parseX11(p)) == -1) {
    log_debug("bad OSC 12: %s", p);
    return;
  }
  screen_set_cursor_colour(ictx->ctx.s, c);
}

/* Handle the OSC 112 sequence for resetting cursor colour. */
static void
input_osc_112(struct input_ctx *ictx, const char *p)
{
  if (*p == '\0') /* no arguments allowed */
    screen_set_cursor_colour(ictx->ctx.s, -1);
}

/* Handle the OSC 133 sequence. */
static void
input_osc_133(struct input_ctx *ictx, const char *p)
{
  struct grid   *gd = ictx->ctx.s->grid;
  u_int      line = ictx->ctx.s->cy + gd->hsize;
  struct grid_line  *gl;

  if (line > gd->hsize + gd->sy - 1)
    return;
  gl = grid_get_line(gd, line);

  switch (*p) {
  case 'A':
    gl->flags |= GRID_LINE_START_PROMPT;
    break;
  case 'C':
    gl->flags |= GRID_LINE_START_OUTPUT;
    break;
  }
}

/* Handle OSC 52 reply. */
static void
input_osc_52_reply(struct input_ctx *ictx, char clip)
{
  struct bufferevent  *ev = ictx->event;
  struct paste_buffer *pb;
  int      state;
  const char    *buf;
  size_t       len;

  state = options_get_number(global_options, "get-clipboard");
  if (state == 0)
    return;
  if (state == 1) {
    if ((pb = paste_get_top(NULL)) == NULL)
      return;
    buf = paste_buffer_data(pb, &len);
    if (ictx->input_end == INPUT_END_BEL)
      input_reply_clipboard(ev, buf, len, "\007", clip);
    else
      input_reply_clipboard(ev, buf, len, "\033\\", clip);
    return;
  }
  input_add_request(ictx, INPUT_REQUEST_CLIPBOARD, ictx->input_end);
}

/*
 * Parse and decode OSC 52 clipboard data. Returns 0 on failure or if handled
 * as a query. On success, returns 1 and sets *out, *outlen, and *flags (caller
 * must free *out).
 */
static int
input_osc_52_parse(struct input_ctx *ictx, const char *p, u_char **out,
    int *outlen, char *clip)
{
  char    *end;
  size_t     len;
  const char  *allow = "cpqs01234567";
  u_int    i, j = 0;

  if (options_get_number(global_options, "set-clipboard") != 2)
    return (0);

  if ((end = strchr(p, ';')) == NULL)
    return (0);
  end++;
  if (*end == '\0')
    return (0);
  log_debug("%s: %s", __func__, end);

  for (i = 0; p + i != end; i++) {
    if (strchr(allow, p[i]) != NULL && strchr(clip, p[i]) == NULL)
      clip[j++] = p[i];
  }
  log_debug("%s: %.*s %s", __func__, (int)(end - p - 1), p, clip);

  if (strcmp(end, "?") == 0) {
    input_osc_52_reply(ictx, *clip);
    return (0);
  }

  len = ((strlen(end) + 3) / 4) * 3;
  if (len == 0)
    return (0);

  *out = xmalloc(len);
  if ((*outlen = b64_pton(end, *out, len)) == -1) {
    free(*out);
    *out = NULL;
    return (0);
  }

  return (1);
}

/* Handle the OSC 52 sequence for setting the clipboard. */
static void
input_osc_52(struct input_ctx *ictx, const char *p)
{
  struct window_pane  *wp = ictx->wp;
  struct screen_write_ctx  ctx;
  u_char      *out;
  int      outlen;
  char       clip[sizeof "cpqs01234567"] = "";

  if (!input_osc_52_parse(ictx, p, &out, &outlen, clip))
    return;

  if (wp == NULL) {
    /* Popup window. */
    if (ictx->c == NULL) {
      free(out);
      return;
    }
    tty_set_selection(&ictx->c->tty, clip, out, outlen);
    paste_add(NULL, out, outlen);
  } else {
    /* Normal window. */
    screen_write_start_pane(&ctx, wp, NULL);
    screen_write_setselection(&ctx, clip, out, outlen);
    screen_write_stop(&ctx);
    notify_pane("pane-set-clipboard", wp);
    paste_add(NULL, out, outlen);
  }
}

/* Handle the OSC 104 sequence for unsetting (multiple) palette entries. */
static void
input_osc_104(struct input_ctx *ictx, const char *p)
{
  char  *copy, *s;
  long   idx;
  int  bad = 0, redraw = 0;

  if (*p == '\0') {
    colour_palette_clear(ictx->palette);
    screen_write_fullredraw(&ictx->ctx);
    return;
  }

  copy = s = xstrdup(p);
  while (*s != '\0') {
    idx = strtol(s, &s, 10);
    if (*s != '\0' && *s != ';') {
      bad = 1;
      break;
    }
    if (idx < 0 || idx >= 256) {
      bad = 1;
      break;
    }
    if (colour_palette_set(ictx->palette, idx, -1))
      redraw = 1;
    if (*s == ';')
      s++;
  }
  if (bad)
    log_debug("bad OSC 104: %s", p);
  if (redraw)
    screen_write_fullredraw(&ictx->ctx);
  free(copy);
}

/* Send a clipboard reply. */
void
input_reply_clipboard(struct bufferevent *bev, const char *buf, size_t len,
    const char *end, char clip)
{
  char  *out = NULL;
  int  outlen = 0;

  if (buf != NULL && len != 0) {
    if (len >= ((size_t)INT_MAX * 3 / 4) - 1)
      return;
    outlen = 4 * ((len + 2) / 3) + 1;
    out = xmalloc(outlen);
    if ((outlen = b64_ntop(buf, len, out, outlen)) == -1) {
      free(out);
      return;
    }
  }

  bufferevent_write(bev, "\033]52;", 5);
  if (clip != 0)
    bufferevent_write(bev, &clip, 1);
  bufferevent_write(bev, ";", 1);
  if (outlen != 0)
    bufferevent_write(bev, out, outlen);
  bufferevent_write(bev, end, strlen(end));
  free(out);
}

/* Set input buffer size. */
void
input_set_buffer_size(size_t buffer_size)
{
  log_debug("%s: %lu -> %lu", __func__, input_buffer_size, buffer_size);
  input_buffer_size = buffer_size;
}

/* Request timer. Remove any requests that are too old. */
static void
input_request_timer_callback(__unused int fd, __unused short events, void *arg)
{
  struct input_ctx  *ictx = arg;
  struct input_request  *ir, *ir1;
  uint64_t     t = get_timer();

  TAILQ_FOREACH_SAFE(ir, &ictx->requests, entry, ir1) {
    if (ir->t >= t - INPUT_REQUEST_TIMEOUT)
      continue;
    if (ir->type == INPUT_REQUEST_QUEUE)
      input_send_reply(ir->ictx, ir->data);
    input_free_request(ir);
  }
  if (ictx->request_count != 0)
    input_start_request_timer(ictx);
}

/* Start the request timer. */
static void
input_start_request_timer(struct input_ctx *ictx)
{
  struct timeval  tv = { .tv_sec = 0, .tv_usec = 100000 };

  event_del(&ictx->request_timer);
  event_add(&ictx->request_timer, &tv);
}

/* Create a request. */
static struct input_request *
input_make_request(struct input_ctx *ictx, enum input_request_type type)
{
  struct input_request  *ir;

  ir = xcalloc (1, sizeof *ir);
  ir->type = type;
  ir->ictx = ictx;
  ir->t = get_timer();

  if (++ictx->request_count == 1)
    input_start_request_timer(ictx);
  TAILQ_INSERT_TAIL(&ictx->requests, ir, entry);

  return (ir);
}

/* Free a request. */
static void
input_free_request(struct input_request *ir)
{
  struct input_ctx  *ictx = ir->ictx;

  if (ir->c != NULL)
    TAILQ_REMOVE(&ir->c->input_requests, ir, centry);

  ictx->request_count--;
  TAILQ_REMOVE(&ictx->requests, ir, entry);

  free(ir->data);
  free(ir);
}

/* Add a request. */
static int
input_add_request(struct input_ctx *ictx, enum input_request_type type, int idx)
{
  struct window_pane  *wp = ictx->wp;
  struct window   *w;
  struct client   *c = NULL, *loop;
  struct input_request  *ir;
  char       s[64];

  if (wp == NULL)
    return (-1);
  w = wp->window;

  TAILQ_FOREACH(loop, &clients, entry) {
    if (loop->flags & CLIENT_UNATTACHEDFLAGS)
      continue;
    if (loop->session == NULL || !session_has(loop->session, w))
      continue;
    if (~loop->tty.flags & TTY_STARTED)
      continue;
    if (c == NULL)
      c = loop;
    else if (timercmp(&loop->activity_time, &c->activity_time, >))
      c = loop;
  }
  if (c == NULL)
    return (-1);

  ir = input_make_request(ictx, type);
  ir->c = c;
  ir->idx = idx;
  ir->end = ictx->input_end;
  TAILQ_INSERT_TAIL(&c->input_requests, ir, centry);

  switch (type) {
  case INPUT_REQUEST_PALETTE:
    xsnprintf(s, sizeof s, "\033]4;%d;?\033\\", idx);
    tty_puts(&c->tty, s);
    break;
  case INPUT_REQUEST_CLIPBOARD:
    tty_putcode_ss(&c->tty, TTYC_MS, "", "?");
    break;
  case INPUT_REQUEST_QUEUE:
    break;
  }

  return (0);
}

/* Handle a palette reply. */
static void
input_request_palette_reply(struct input_request *ir, void *data)
{
  struct input_request_palette_data *pd = data;

  input_osc_colour_reply(ir->ictx, 0, 4, pd->idx, pd->c, ir->end);
}

/* Handle a clipboard reply. */
static void
input_request_clipboard_reply(struct input_request *ir, void *data)
{
  struct input_ctx      *ictx = ir->ictx;
  struct bufferevent      *ev = ictx->event;
  struct input_request_clipboard_data *cd = data;
  int          state;
  char          *copy;

  state = options_get_number(global_options, "get-clipboard");
  if (state == 0 || state == 1)
    return;
  if (state == 3) {
    copy = xmalloc(cd->len);
    memcpy(copy, cd->buf, cd->len);
    paste_add(NULL, copy, cd->len);
  }

  if (ir->idx == INPUT_END_BEL)
    input_reply_clipboard(ev, cd->buf, cd->len, "\007", cd->clip);
  else
    input_reply_clipboard(ev, cd->buf, cd->len, "\033\\", cd->clip);
}

/* Handle a reply to a request. */
void
input_request_reply(struct client *c, enum input_request_type type, void *data)
{
  struct input_request      *ir, *ir1, *found = NULL;
  struct input_request_palette_data *pd = data;
  int          complete = 0;

  TAILQ_FOREACH_SAFE(ir, &c->input_requests, centry, ir1) {
    if (ir->type != type) {
      input_free_request(ir);
      continue;
    }
    if (type == INPUT_REQUEST_PALETTE) {
      if (pd->idx != ir->idx) {
        input_free_request(ir);
        continue;
      }
      found = ir;
      break;
    }
    if (type == INPUT_REQUEST_CLIPBOARD) {
      found = ir;
      break;
    }
  }
  if (found == NULL)
    return;

  TAILQ_FOREACH_SAFE(ir, &found->ictx->requests, entry, ir1) {
    if (complete && ir->type != INPUT_REQUEST_QUEUE)
      break;
    if (ir->type == INPUT_REQUEST_QUEUE)
      input_send_reply(ir->ictx, ir->data);
    else if (ir == found) {
      if (ir->type == INPUT_REQUEST_PALETTE)
        input_request_palette_reply(ir, data);
      else if (ir->type == INPUT_REQUEST_CLIPBOARD)
        input_request_clipboard_reply(ir, data);
      complete = 1;
    }
    input_free_request(ir);
  }
}

/* Cancel pending requests for client. */
void
input_cancel_requests(struct client *c)
{
  struct input_request  *ir, *ir1;

  TAILQ_FOREACH_SAFE(ir, &c->input_requests, centry, ir1)
    input_free_request(ir);
}

/* Report current theme. */
static void
input_report_current_theme(struct input_ctx *ictx)
{
  struct window_pane  *wp = ictx->wp;

  if (wp != NULL) {
    wp->last_theme = window_pane_get_theme(wp);
    wp->flags &= ~PANE_THEMECHANGED;

    switch (wp->last_theme) {
    case THEME_DARK:
      log_debug("%s: %%%u dark theme", __func__, wp->id);
      input_reply(ictx, 0, "\033[?997;1n");
      break;
    case THEME_LIGHT:
      log_debug("%s: %%%u light theme", __func__, wp->id);
      input_reply(ictx, 0, "\033[?997;2n");
      break;
    case THEME_UNKNOWN:
      log_debug("%s: %%%u unknown theme", __func__, wp->id);
      break;
    }
  }
}

Coverage Report

Created: 2026-05-30 06:39