From 743ab5728da1ce950a3782d5bc08831f61c5d744 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Tue, 21 Jul 2020 05:24:33 +0000
Subject: [PATCH] Fix show-buffer when run from inside tmux, GitHub issue 2314.

---
 cmd-save-buffer.c | 14 +++++++++++---
 screen-write.c    |  5 ++++-
 tmux.h            |  1 +
 utf8.c            | 14 ++++++++++++++
 4 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/cmd-save-buffer.c b/cmd-save-buffer.c
index a6ad188f..5e45e279 100644
--- a/cmd-save-buffer.c
+++ b/cmd-save-buffer.c
@@ -74,11 +74,12 @@ static enum cmd_retval
 cmd_save_buffer_exec(struct cmd *self, struct cmdq_item *item)
 {
 	struct args		*args = cmd_get_args(self);
+	struct client		*c = cmdq_get_client(item);
 	struct paste_buffer	*pb;
 	int			 flags;
 	const char		*bufname = args_get(args, 'b'), *bufdata;
 	size_t			 bufsize;
-	char			*path;
+	char			*path, *tmp;
 
 	if (bufname == NULL) {
 		if ((pb = paste_get_top(NULL)) == NULL) {
@@ -94,9 +95,16 @@ cmd_save_buffer_exec(struct cmd *self, struct cmdq_item *item)
 	}
 	bufdata = paste_buffer_data(pb, &bufsize);
 
-	if (cmd_get_entry(self) == &cmd_show_buffer_entry)
+	if (cmd_get_entry(self) == &cmd_show_buffer_entry) {
+		if (c->session != NULL || (c->flags & CLIENT_CONTROL)) {
+			utf8_stravisx(&tmp, bufdata, bufsize,
+			    VIS_OCTAL|VIS_CSTYLE|VIS_TAB);
+			cmdq_print(item, "%s", tmp);
+			free(tmp);
+			return (CMD_RETURN_NORMAL);
+		}
 		path = xstrdup("-");
-	else
+	} else
 		path = format_single_from_target(item, args->argv[0]);
 	if (args_has(args, 'a'))
 		flags = O_APPEND;
diff --git a/screen-write.c b/screen-write.c
index 16a9c1d7..c9c61086 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -514,7 +514,10 @@ screen_write_vnputs(struct screen_write_ctx *ctx, ssize_t maxlen,
 
 			if (*ptr == '\001')
 				gc.attr ^= GRID_ATTR_CHARSET;
-			else if (*ptr > 0x1f && *ptr < 0x7f) {
+			else if (*ptr == '\n') {
+				screen_write_linefeed(ctx, 0, 8);
+				screen_write_carriagereturn(ctx);
+			} else if (*ptr > 0x1f && *ptr < 0x7f) {
 				size++;
 				screen_write_putc(ctx, &gc, *ptr);
 			}
diff --git a/tmux.h b/tmux.h
index 07dfc0ae..a6749e99 100644
--- a/tmux.h
+++ b/tmux.h
@@ -2940,6 +2940,7 @@ enum utf8_state	 utf8_append(struct utf8_data *, u_char);
 int		 utf8_isvalid(const char *);
 int		 utf8_strvis(char *, const char *, size_t, int);
 int		 utf8_stravis(char **, const char *, int);
+int		 utf8_stravisx(char **, const char *, size_t, int);
 char		*utf8_sanitize(const char *);
 size_t		 utf8_strlen(const struct utf8_data *);
 u_int		 utf8_strwidth(const struct utf8_data *, ssize_t);
diff --git a/utf8.c b/utf8.c
index e3fe570d..36c9daad 100644
--- a/utf8.c
+++ b/utf8.c
@@ -341,6 +341,20 @@ utf8_stravis(char **dst, const char *src, int flag)
 	return (len);
 }
 
+/* Same as utf8_strvis but allocate the buffer. */
+int
+utf8_stravisx(char **dst, const char *src, size_t srclen, int flag)
+{
+	char	*buf;
+	int	 len;
+
+	buf = xreallocarray(NULL, 4, srclen + 1);
+	len = utf8_strvis(buf, src, srclen, flag);
+
+	*dst = xrealloc(buf, len + 1);
+	return (len);
+}
+
 /* Does this string contain anything that isn't valid UTF-8? */
 int
 utf8_isvalid(const char *s)