Try to resolve relative paths for loadb and saveb (first using client

working directory if any then default-path or session wd).

cmd-load-buffer.c

@@ -48,8 +48,9 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 {
 	struct args	*args = self->args;
 	struct client	*c = ctx->cmdclient;
+	struct session  *s;
 	FILE		*f;
-	const char	*path;
+	const char	*path, *newpath, *wd;
 	char		*pdata, *new_pdata, *cause;
 	size_t		 psize;
 	u_int		 limit;
@@ -93,6 +94,19 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 		return (1);
 	}
 
+	if (c != NULL)
+		wd = c->cwd;
+	else if ((s = cmd_current_session(ctx, 0)) != NULL) {
+		wd = options_get_string(&s->options, "default-path");
+		if (*wd == '\0')
+			wd = s->cwd;
+	} else
+		wd = NULL;
+	if (wd != NULL && *wd != '\0') {
+		newpath = get_full_path(wd, path);
+		if (newpath != NULL)
+			path = newpath;
+	}
 	if ((f = fopen(path, "rb")) == NULL) {
 		ctx->error(ctx, "%s: %s", path, strerror(errno));
 		return (-1);

cmd-save-buffer.c

@@ -45,8 +45,9 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 {
 	struct args		*args = self->args;
 	struct client		*c = ctx->cmdclient;
+	struct session          *s;
 	struct paste_buffer	*pb;
-	const char		*path;
+	const char		*path, *newpath, *wd;
 	char			*cause;
 	int			 buffer;
 	mode_t			 mask;
@@ -80,6 +81,20 @@ cmd_save_buffer_exec(struct cmd *self, struct cmd_ctx *ctx)
 		}
 		bufferevent_write(c->stdout_event, pb->data, pb->size);
 	} else {
+		if (c != NULL)
+			wd = c->cwd;
+		else if ((s = cmd_current_session(ctx, 0)) != NULL) {
+			wd = options_get_string(&s->options, "default-path");
+			if (*wd == '\0')
+				wd = s->cwd;
+		} else
+			wd = NULL;
+		if (wd != NULL && *wd != '\0') {
+			newpath = get_full_path(wd, path);
+			if (newpath != NULL)
+				path = newpath;
+		}
+
 		mask = umask(S_IRWXG | S_IRWXO);
 		if (args_has(self->args, 'a'))
 			f = fopen(path, "ab");

tmux.c

@@ -124,6 +124,22 @@ areshell(const char *shell)
 	return (0);
 }
 
+const char*
+get_full_path(const char *wd, const char *path)
+{
+	static char	newpath[MAXPATHLEN];
+	char		oldpath[MAXPATHLEN];
+
+	if (getcwd(oldpath, sizeof oldpath) == NULL)
+		return (NULL);
+	if (chdir(wd) != 0)
+		return (NULL);
+	if (realpath(path, newpath) != 0)
+		return (NULL);
+	chdir(oldpath);
+	return (newpath);
+}
+
 void
 parseenvironment(void)
 {

tmux.h

@@ -1345,6 +1345,7 @@ void		 logfile(const char *);
 const char	*getshell(void);
 int		 checkshell(const char *);
 int		 areshell(const char *);
+const char*	 get_full_path(const char *, const char *);
 void		 setblocking(int, int);
 __dead void	 shell_exec(const char *, const char *);