flake/overlays/tmux-get_clipboard.diff

# source: https://github.com/tmux/tmux/issues/4275
diff --git a/input.c b/input.c
index 3a61ec26..58a1b091 100644
--- a/input.c
+++ b/input.c
@@ -3069,18 +3069,41 @@ input_osc_133(struct input_ctx *ictx, const char *p)
 	}
 }
 
+/* Handle OSC 52 reply. */
+static void
+input_osc_52_reply(struct input_ctx *ictx)
+{
+	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(ictx->event, buf, len, "\007");
+		else
+			input_reply_clipboard(ictx->event, buf, len, "\033\\");
+		return;
+	}
+	input_add_request(ictx, INPUT_REQUEST_CLIPBOARD, ictx->input_end);
+}
+
 /* 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;
+	size_t			 len;
 	char			*end;
-	const char		*buf = NULL;
-	size_t			 len = 0;
 	u_char			*out;
 	int			 outlen, state;
 	struct screen_write_ctx	 ctx;
-	struct paste_buffer	*pb;
 	const char*		 allow = "cpqs01234567";
 	char			 flags[sizeof "cpqs01234567"] = "";
 	u_int			 i, j = 0;
@@ -3105,12 +3128,7 @@ input_osc_52(struct input_ctx *ictx, const char *p)
 	log_debug("%s: %.*s %s", __func__, (int)(end - p - 1), p, flags);
 
 	if (strcmp(end, "?") == 0) {
-		if ((pb = paste_get_top(NULL)) != NULL)
-			buf = paste_buffer_data(pb, &len);
-		if (ictx->input_end == INPUT_END_BEL)
-			input_reply_clipboard(ictx->event, buf, len, "\007");
-		else
-			input_reply_clipboard(ictx->event, buf, len, "\033\\");
+		input_osc_52_reply(ictx);
 		return;
 	}
 
@@ -3169,6 +3187,7 @@ input_osc_104(struct input_ctx *ictx, const char *p)
 	free(copy);
 }
 
+/* Send a clipboard reply. */
 void
 input_reply_clipboard(struct bufferevent *bev, const char *buf, size_t len,
     const char *end)
@@ -3305,6 +3324,9 @@ input_add_request(struct input_ctx *ictx, enum input_request_type type, int idx)
 		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;
 	}
@@ -3312,6 +3334,39 @@ input_add_request(struct input_ctx *ictx, enum input_request_type type, int idx)
 	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 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(ictx->event, cd->buf, cd->len, "\007");
+	else
+		input_reply_clipboard(ictx->event, cd->buf, cd->len, "\033\\");
+}
+
 /* Handle a reply to a request. */
 void
 input_request_reply(struct client *c, enum input_request_type type, void *data)
@@ -3321,11 +3376,18 @@ input_request_reply(struct client *c, enum input_request_type type, void *data)
 	int					 complete = 0;
 
 	TAILQ_FOREACH_SAFE(ir, &c->input_requests, centry, ir1) {
-		if (ir->type == type && pd->idx == ir->idx) {
+		if (ir->type != type) {
+			input_free_request(ir);
+			continue;
+		}
+		if (type == INPUT_REQUEST_PALETTE && pd->idx == ir->idx) {
+			found = ir;
+			break;
+		}
+		if (type == INPUT_REQUEST_CLIPBOARD) {
 			found = ir;
 			break;
 		}
-		input_free_request(ir);
 	}
 	if (found == NULL)
 		return;
@@ -3335,8 +3397,11 @@ input_request_reply(struct client *c, enum input_request_type type, void *data)
 			break;
 		if (ir->type == INPUT_REQUEST_QUEUE)
 			input_send_reply(ir->ictx, ir->data);
-		else if (ir == found && ir->type == INPUT_REQUEST_PALETTE) {
-			input_osc_colour_reply(ir->ictx, 0, 4, pd->idx, pd->c, ir->end);
+		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);
diff --git a/options-table.c b/options-table.c
index 6946a085..b3ba39cd 100644
--- a/options-table.c
+++ b/options-table.c
@@ -84,6 +84,9 @@ static const char *options_table_popup_border_lines_list[] = {
 static const char *options_table_set_clipboard_list[] = {
 	"off", "external", "on", NULL
 };
+static const char *options_table_get_clipboard_list[] = {
+	"off", "buffer", "request", "both", NULL
+};
 static const char *options_table_window_size_list[] = {
 	"largest", "smallest", "manual", "latest", NULL
 };
@@ -405,6 +408,18 @@ const struct options_table_entry options_table[] = {
 	  .text = "Whether to send focus events to applications."
 	},
 
+	{ .name = "get-clipboard",
+	  .type = OPTIONS_TABLE_CHOICE,
+	  .scope = OPTIONS_TABLE_SERVER,
+	  .choices = options_table_get_clipboard_list,
+	  .default_num = 1,
+	  .text = "When an application requests the clipboard, whether to "
+	          "ignore the request ('off'); respond with the newest buffer "
+	          "('buffer'); request the clipboard from the most recently "
+	          "used terminal ('request'); or to request the clipboard, "
+	          "create a buffer, and send it to the application ('both')."
+	},
+
 	{ .name = "history-file",
 	  .type = OPTIONS_TABLE_STRING,
 	  .scope = OPTIONS_TABLE_SERVER,
diff --git a/tmux.1 b/tmux.1
index a25da1fb..2ae1b724 100644
--- a/tmux.1
+++ b/tmux.1
@@ -4241,6 +4241,32 @@ passed through to applications running in
 .Nm .
 Attached clients should be detached and attached again after changing this
 option.
+.It Xo Ic get-clipboard
+.Op Ic both | request | buffer | off
+.Xc
+Controls the behaviour when an application requests the clipboard from
+.Nm .
+.Pp
+If
+.Ic off ,
+the request is ignored;
+if
+.Ic buffer ,
+.Nm
+responds with the newest paste buffer;
+.Ic request
+causes
+.Nm
+to request the clipboard from the most recently used client (if possible) and
+send the reply (if any) back to the application;
+.Ic buffer
+is the same as
+.Ic request
+but also creates a paste buffer.
+.Pp
+See also the
+.Ic set-clipboard
+option.
 .It Ic history-file Ar path
 If not empty, a file to which
 .Nm
diff --git a/tmux.h b/tmux.h
index c3959d2a..3dece217 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1129,6 +1129,7 @@ struct window_mode_entry {
 /* Type of request to client. */
 enum input_request_type {
 	INPUT_REQUEST_PALETTE,
+	INPUT_REQUEST_CLIPBOARD,
 	INPUT_REQUEST_QUEUE
 };
 
@@ -1138,6 +1139,12 @@ struct input_request_palette_data {
 	int	c;
 };
 
+/* Clipboard request reply data. */
+struct input_request_clipboard_data {
+	char	*buf;
+	size_t	 len;
+};
+
 /* Request sent to client on behalf of pane. */
 TAILQ_HEAD(input_requests, input_request);
 
diff --git a/tty-keys.c b/tty-keys.c
index 77254591..7acee80f 100644
--- a/tty-keys.c
+++ b/tty-keys.c
@@ -1301,12 +1301,13 @@ tty_keys_mouse(struct tty *tty, const char *buf, size_t len, size_t *size,
 static int
 tty_keys_clipboard(struct tty *tty, const char *buf, size_t len, size_t *size)
 {
-	struct client		*c = tty->client;
-	struct window_pane	*wp;
-	size_t			 end, terminator = 0, needed;
-	char			*copy, *out;
-	int			 outlen;
-	u_int			 i;
+	struct client				*c = tty->client;
+	struct window_pane			*wp;
+	size_t					 end, terminator = 0, needed;
+	char					*copy, *out;
+	int			 		 outlen;
+	u_int			 		 i;
+	struct input_request_clipboard_data	 cd;
 
 	*size = 0;
 
@@ -1364,12 +1365,6 @@ tty_keys_clipboard(struct tty *tty, const char *buf, size_t len, size_t *size)
 	buf++;
 	end--;
 
-	/* If we did not request this, ignore it. */
-	if (~tty->flags & TTY_OSC52QUERY)
-		return (0);
-	tty->flags &= ~TTY_OSC52QUERY;
-	evtimer_del(&tty->clipboard_timer);
-
 	/* It has to be a string so copy it. */
 	copy = xmalloc(end + 1);
 	memcpy(copy, buf, end);
@@ -1384,18 +1379,37 @@ tty_keys_clipboard(struct tty *tty, const char *buf, size_t len, size_t *size)
 		return (0);
 	}
 	free(copy);
-
-	/* Create a new paste buffer and forward to panes. */
 	log_debug("%s: %.*s", __func__, outlen, out);
-	if (c->flags & CLIENT_CLIPBOARDBUFFER) {
-		paste_add(NULL, out, outlen);
-		c->flags &= ~CLIENT_CLIPBOARDBUFFER;
+
+	/* Set reply if any. */
+	if (c->clipboard_npanes == 0) {
+		cd.buf = out;
+		cd.len = outlen;
+		input_request_reply(c, INPUT_REQUEST_CLIPBOARD, &cd);
+		free(out);
+		return (0);
 	}
+
+	/* If we did not request this, ignore it. */
+	if (~tty->flags & TTY_OSC52QUERY) {
+		free(out);
+		return (0);
+	}
+	tty->flags &= ~TTY_OSC52QUERY;
+	evtimer_del(&tty->clipboard_timer);
+
+	/* Create a new paste buffer and forward to panes. */
 	for (i = 0; i < c->clipboard_npanes; i++) {
 		wp = window_pane_find_by_id(c->clipboard_panes[i]);
 		if (wp != NULL)
 			input_reply_clipboard(wp->event, out, outlen, "\033\\");
 	}
+	if (~c->flags & CLIENT_CLIPBOARDBUFFER)
+		free (out);
+	else {
+		paste_add(NULL, out, outlen);
+		c->flags &= ~CLIENT_CLIPBOARDBUFFER;
+	}
 	free(c->clipboard_panes);
 	c->clipboard_panes = NULL;
 	c->clipboard_npanes = 0;