Alter how tmux handles the working directory to internally use file descriptors

rather than strings.

- Each session still has a current working directory.

- New sessions still get their working directory from the client that created
  them or its attached session if any.

- New windows are created by default in the session working directory.

- The -c flag to new, neww, splitw allows the working directory to be
  overridden.

- The -c flag to attach let's the session working directory be changed.

- The default-path option has been removed.

To get the equivalent to default-path '.', do:

        bind c neww -c $PWD

To get the equivalent of default-path '', do:

        bind c neww -c '#{pane_current_path}'

The equivalent of default-path '~' is left as an exercise for the reader.

This also changes the client identify protocol to be a set of messages rather
than one as well as some other changes that should make it easier to make
backwards-compatible protocol changes in future.

1 files changed, 14 insertions, 16 deletions

diff --git a/cmd-load-buffer.c b/cmd-load-buffer.c
index 82b8f574..4acbab5e 100644
--- a/cmd-load-buffer.c
+++ b/cmd-load-buffer.c
@@ -19,6 +19,7 @@
 #include <sys/types.h>
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -49,11 +50,11 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 	struct client	*c = cmdq->client;
 	struct session  *s;
 	FILE		*f;
-	const char	*path, *newpath, *wd;
+	const char	*path;
 	char		*pdata, *new_pdata, *cause;
 	size_t		 psize;
 	u_int		 limit;
-	int		 ch, error, buffer, *buffer_ptr;
+	int		 ch, error, buffer, *buffer_ptr, cwd, fd;
 
 	if (!args_has(args, 'b'))
 		buffer = -1;
@@ -81,20 +82,17 @@ cmd_load_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 		return (CMD_RETURN_WAIT);
 	}
 
-	if (c != NULL)
-		wd = c->cwd;
-	else if ((s = cmd_current_session(cmdq, 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) {
+	if (c != NULL && c->session == NULL)
+		cwd = c->cwd;
+	else if ((s = cmd_current_session(cmdq, 0)) != NULL)
+		cwd = s->cwd;
+	else
+		cwd = AT_FDCWD;
+
+	if ((fd = openat(cwd, path, O_RDONLY)) == -1 ||
+	    (f = fdopen(fd, "rb")) == NULL) {
+		if (fd != -1)
+			close(fd);
 		cmdq_error(cmdq, "%s: %s", path, strerror(errno));
 		return (CMD_RETURN_ERROR);
 	}