From c5dda82c51f3caf94d5a611b06a3be6dca90643b Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Sun, 26 Aug 2018 09:28:42 +0000
Subject: [PATCH] Add q: format prefix to escape sh(1) special characters.
 Suggested by someone ages ago and then more recently in GitHub issue 1449.

---
 usr.bin/tmux/format.c | 31 ++++++++++++++++++++++++++++++-
 usr.bin/tmux/tmux.1   |  8 ++++++--
 2 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/usr.bin/tmux/format.c b/usr.bin/tmux/format.c
index d573e878148..91540238436 100644
--- a/usr.bin/tmux/format.c
+++ b/usr.bin/tmux/format.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: format.c,v 1.160 2018/08/23 15:45:05 nicm Exp $ */
+/* $OpenBSD: format.c,v 1.161 2018/08/26 09:28:42 nicm Exp $ */
 
 /*
  * Copyright (c) 2011 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -94,6 +94,7 @@ format_job_cmp(struct format_job *fj1, struct format_job *fj2)
 #define FORMAT_BASENAME 0x2
 #define FORMAT_DIRNAME 0x4
 #define FORMAT_SUBSTITUTE 0x8
+#define FORMAT_QUOTE 0x10
 
 /* Entry in format tree. */
 struct format_entry {
@@ -754,6 +755,23 @@ format_add_cb(struct format_tree *ft, const char *key, format_cb cb)
 	fe->value = NULL;
 }
 
+/* Quote special characters in string. */
+static char *
+format_quote(const char *s)
+{
+	const char	*cp;
+	char		*out, *at;
+
+	at = out = xmalloc(strlen(s) * 2 + 1);
+	for (cp = s; *cp != '\0'; cp++) {
+		if (strchr("|&;<>()$`\\\"'*?[# =%", *cp) != NULL)
+			*at++ = '\\';
+		*at++ = *cp;
+	}
+	*at = '\0';
+	return (out);
+}
+
 /* Find a format entry. */
 static char *
 format_find(struct format_tree *ft, const char *key, int modifiers)
@@ -836,6 +854,11 @@ found:
 		copy = xstrdup(dirname(saved));
 		free(saved);
 	}
+	if (modifiers & FORMAT_QUOTE) {
+		saved = copy;
+		copy = xstrdup(format_quote(saved));
+		free(saved);
+	}
 	return (copy);
 }
 
@@ -976,6 +999,12 @@ format_replace(struct format_tree *ft, const char *key, size_t keylen,
 		modifiers |= FORMAT_TIMESTRING;
 		copy += 2;
 		break;
+	case 'q':
+		if (copy[1] != ':')
+			break;
+		modifiers |= FORMAT_QUOTE;
+		copy += 2;
+		break;
 	case 's':
 		sep = copy[1];
 		if (sep == ':' || !ispunct((u_char)sep))
diff --git a/usr.bin/tmux/tmux.1 b/usr.bin/tmux/tmux.1
index fb37e3b85bb..eca8e2afeec 100644
--- a/usr.bin/tmux/tmux.1
+++ b/usr.bin/tmux/tmux.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: tmux.1,v 1.609 2018/08/22 20:06:14 nicm Exp $
+.\" $OpenBSD: tmux.1,v 1.610 2018/08/26 09:28:42 nicm Exp $
 .\"
 .\" Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 .\"
@@ -14,7 +14,7 @@
 .\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 .\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: August 22 2018 $
+.Dd $Mdocdate: August 26 2018 $
 .Dt TMUX 1
 .Os
 .Sh NAME
@@ -3676,6 +3676,10 @@ prefixes are
 and
 .Xr dirname 3
 of the variable respectively.
+.Ql q:
+will escape
+.Xr sh 1
+special characters.
 A prefix of the form
 .Ql s/foo/bar/:
 will substitute
-- 
2.20.1