From: nicm <nicm@openbsd.org>
Date: Thu, 3 Oct 2024 05:41:59 +0000 (+0000)
Subject: Improve fix for shifted keys so it works for all the keys it should,
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=3835afffd9e0c4fae7ff4211e466db358c7cba53;p=openbsd

Improve fix for shifted keys so it works for all the keys it should,
Stanislav Kljuhhin in GitHub issue 4146.
---

diff --git a/usr.bin/tmux/input-keys.c b/usr.bin/tmux/input-keys.c
index f7756858760..fc6cf7f82d1 100644
--- a/usr.bin/tmux/input-keys.c
+++ b/usr.bin/tmux/input-keys.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: input-keys.c,v 1.100 2024/10/02 08:06:45 nicm Exp $ */
+/* $OpenBSD: input-keys.c,v 1.101 2024/10/03 05:41:59 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -557,10 +557,6 @@ input_key_mode1(struct bufferevent *bev, key_code key)
 	     (onlykey >= '@' && onlykey <= '~')))
 		return (input_key_vt10x(bev, key));
 
-	/* Avoid reporting A as Shift-A, which is not expected in mode 1. */
-	if ((key & KEYC_MASK_MODIFIERS) == KEYC_SHIFT)
-		return (input_key_vt10x(bev, key));
-
 	/*
 	 * A regular key + Meta. In the absence of a standard to back this, we
 	 * mimic what iTerm 2 does.
diff --git a/usr.bin/tmux/tty-keys.c b/usr.bin/tmux/tty-keys.c
index e01f52ac53a..d95ded39361 100644
--- a/usr.bin/tmux/tty-keys.c
+++ b/usr.bin/tmux/tty-keys.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty-keys.c,v 1.180 2024/10/01 06:15:47 nicm Exp $ */
+/* $OpenBSD: tty-keys.c,v 1.181 2024/10/03 05:41:59 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1016,7 +1016,7 @@ tty_keys_extended_key(struct tty *tty, const char *buf, size_t len,
 	u_int		 number, modifiers;
 	char		 tmp[64];
 	cc_t		 bspace;
-	key_code	 nkey;
+	key_code	 nkey, onlykey;
 	struct utf8_data ud;
 	utf8_char        uc;
 
@@ -1080,13 +1080,7 @@ tty_keys_extended_key(struct tty *tty, const char *buf, size_t len,
 	/* Update the modifiers. */
 	if (modifiers > 0) {
 		modifiers--;
-		/*
-		 * The Shift modifier may not be reported in some input modes,
-		 * which is unfortunate, as in general case determining if a
-		 * character is shifted or not requires knowing the input
-		 * keyboard layout. So we only fix up the trivial case.
-		 */
-		if (modifiers & 1 || (nkey >= 'A' && nkey <= 'Z'))
+		if (modifiers & 1)
 			nkey |= KEYC_SHIFT;
 		if (modifiers & 2)
 			nkey |= (KEYC_META|KEYC_IMPLIED_META); /* Alt */
@@ -1100,6 +1094,26 @@ tty_keys_extended_key(struct tty *tty, const char *buf, size_t len,
 	if ((nkey & KEYC_MASK_KEY) == '\011' && (nkey & KEYC_SHIFT))
 		nkey = KEYC_BTAB | (nkey & ~KEYC_MASK_KEY & ~KEYC_SHIFT);
 
+	/*
+	 * Deal with the Shift modifier when present alone. The problem is that
+	 * in mode 2 some terminals would report shifted keys, like S-a, as
+	 * just A, and some as S-A.
+	 *
+	 * Because we need an unambiguous internal representation, and because
+	 * restoring the Shift modifier when it's missing would require knowing
+	 * the keyboard layout, and because S-A would cause a lot of issues
+	 * downstream, we choose to lose the Shift for all printable
+	 * characters.
+	 *
+	 * That still leaves some ambiguity, such as C-S-A vs. C-A, but that's
+	 * OK, and applications can handle that.
+	 */
+	onlykey = nkey & KEYC_MASK_KEY;
+	if (((onlykey > 0x20 && onlykey < 0x7f) ||
+	    KEYC_IS_UNICODE(nkey)) &&
+	    (nkey & KEYC_MASK_MODIFIERS) == KEYC_SHIFT)
+		nkey &= ~KEYC_SHIFT;
+
 	if (log_get_level() != 0) {
 		log_debug("%s: extended key %.*s is %llx (%s)", c->name,
 		    (int)*size, buf, nkey, key_string_lookup_key(nkey, 1));