If a mouse position was above the maximum supported by the normal mouse

protocol (223), tmux was allowing it to wrap around. However, since tmux
was not correctly handling this on input, other programs also do not
handle it correctly, and the alternative SGR mouse mode is now
widespread, this seems unnecessary, so remove this feature. Also define
some constants to make it clearer what the numbers mean. Mostly from
Leonid S Usov in GitHub issue 3165.

1 files changed, 23 insertions, 8 deletions

diff --git a/input-keys.c b/input-keys.c
index 78ae91da..038003df 100644
--- a/input-keys.c
+++ b/input-keys.c
@@ -607,19 +607,34 @@ input_key_get_mouse(struct screen *s, struct mouse_event *m, u_int x, u_int y,
 		len = xsnprintf(buf, sizeof buf, "\033[<%u;%u;%u%c",
 		    m->sgr_b, x + 1, y + 1, m->sgr_type);
 	} else if (s->mode & MODE_MOUSE_UTF8) {
-		if (m->b > 0x7ff - 32 || x > 0x7ff - 33 || y > 0x7ff - 33)
+		if (m->b > MOUSE_PARAM_UTF8_MAX - MOUSE_PARAM_BTN_OFF ||
+		    x > MOUSE_PARAM_UTF8_MAX - MOUSE_PARAM_POS_OFF ||
+		    y > MOUSE_PARAM_UTF8_MAX - MOUSE_PARAM_POS_OFF)
 			return (0);
 		len = xsnprintf(buf, sizeof buf, "\033[M");
-		len += input_key_split2(m->b + 32, &buf[len]);
-		len += input_key_split2(x + 33, &buf[len]);
-		len += input_key_split2(y + 33, &buf[len]);
+		len += input_key_split2(m->b + MOUSE_PARAM_BTN_OFF, &buf[len]);
+		len += input_key_split2(x + MOUSE_PARAM_POS_OFF, &buf[len]);
+		len += input_key_split2(y + MOUSE_PARAM_POS_OFF, &buf[len]);
 	} else {
-		if (m->b > 223)
+		if (m->b + MOUSE_PARAM_BTN_OFF > MOUSE_PARAM_MAX)
 			return (0);
+
 		len = xsnprintf(buf, sizeof buf, "\033[M");
-		buf[len++] = m->b + 32;
-		buf[len++] = x + 33;
-		buf[len++] = y + 33;
+		buf[len++] = m->b + MOUSE_PARAM_BTN_OFF;
+
+		/*
+		 * The incoming x and y may be out of the range which can be
+		 * supported by the "normal" mouse protocol. Clamp the
+		 * coordinates to the supported range.
+		 */
+		if (x + MOUSE_PARAM_POS_OFF > MOUSE_PARAM_MAX)
+			buf[len++] = MOUSE_PARAM_MAX;
+		else
+			buf[len++] = x + MOUSE_PARAM_POS_OFF;
+		if (y + MOUSE_PARAM_POS_OFF > MOUSE_PARAM_MAX)
+			buf[len++] = MOUSE_PARAM_MAX;
+		else
+			buf[len++] = y + MOUSE_PARAM_POS_OFF;
 	}
 
 	*rbuf = buf;