Make update-environment an array as well.

cmd-attach-session.c

@@ -54,7 +54,6 @@ cmd_attach_session(struct cmdq_item *item, int dflag, int rflag,
 	struct client		*c = item->client, *c_loop;
 	struct winlink		*wl = item->state.tflag.wl;
 	struct window_pane	*wp = item->state.tflag.wp;
-	const char		*update;
 	char			*cause, *cwd;
 	struct format_tree	*ft;
 
@@ -95,12 +94,8 @@ cmd_attach_session(struct cmdq_item *item, int dflag, int rflag,
 				server_client_detach(c_loop, MSG_DETACH);
 			}
 		}
-
-		if (!Eflag) {
-			update = options_get_string(s->options,
-			    "update-environment");
-			environ_update(update, c->environ, s->environ);
-		}
+		if (!Eflag)
+			environ_update(s->options, c->environ, s->environ);
 
 		c->session = s;
 		server_client_set_key_table(c, NULL);
@@ -116,7 +111,6 @@ cmd_attach_session(struct cmdq_item *item, int dflag, int rflag,
 			free(cause);
 			return (CMD_RETURN_ERROR);
 		}
-
 		if (rflag)
 			c->flags |= CLIENT_READONLY;
 
@@ -127,12 +121,8 @@ cmd_attach_session(struct cmdq_item *item, int dflag, int rflag,
 				server_client_detach(c_loop, MSG_DETACH);
 			}
 		}
-
-		if (!Eflag) {
-			update = options_get_string(s->options,
-			    "update-environment");
-			environ_update(update, c->environ, s->environ);
-		}
+		if (!Eflag)
+			environ_update(s->options, c->environ, s->environ);
 
 		c->session = s;
 		server_client_set_key_table(c, NULL);

cmd-new-session.c

@@ -73,7 +73,7 @@ cmd_new_session_exec(struct cmd *self, struct cmdq_item *item)
 	struct window		*w;
 	struct environ		*env;
 	struct termios		 tio, *tiop;
-	const char		*newname, *target, *update, *errstr, *template;
+	const char		*newname, *target, *errstr, *template;
 	const char		*path, *cmd, *cwd, *to_free = NULL;
 	char		       **argv, *cause, *cp;
 	int			 detached, already_attached, idx, argc;
@@ -234,11 +234,8 @@ cmd_new_session_exec(struct cmd *self, struct cmdq_item *item)
 
 	/* Construct the environment. */
 	env = environ_create();
-	if (c != NULL && !args_has(args, 'E')) {
-		update = options_get_string(global_s_options,
-		    "update-environment");
-		environ_update(update, c->environ, env);
-	}
+	if (c != NULL && !args_has(args, 'E'))
+		environ_update(global_s_options, c->environ, env);
 
 	/* Create the new session. */
 	idx = -1 - options_get_number(global_s_options, "base-index");

cmd-switch-client.c

@@ -53,7 +53,7 @@ cmd_switch_client_exec(struct cmd *self, struct cmdq_item *item)
 	struct client		*c = state->c;
 	struct session		*s = item->state.tflag.s;
 	struct window_pane	*wp;
-	const char		*tablename, *update;
+	const char		*tablename;
 	struct key_table	*table;
 
 	if (args_has(args, 'r'))
@@ -102,10 +102,8 @@ cmd_switch_client_exec(struct cmd *self, struct cmdq_item *item)
 		}
 	}
 
-	if (!args_has(args, 'E')) {
-		update = options_get_string(s->options, "update-environment");
-		environ_update(update, c->environ, s->environ);
-	}
+	if (!args_has(args, 'E'))
+		environ_update(s->options, c->environ, s->environ);
 
 	if (c->session != NULL && c->session != s)
 		c->last_session = c->session;

environ.c

@@ -169,25 +169,27 @@ environ_unset(struct environ *env, const char *name)
 	free(envent);
 }
 
-/*
- * Copy a space-separated list of variables from a destination into a source
- * environment.
- */
+/* Copy variables from a destination into a source * environment. */
 void
-environ_update(const char *vars, struct environ *srcenv,
-    struct environ *dstenv)
+environ_update(struct options *oo, struct environ *src, struct environ *dst)
 {
 	struct environ_entry	*envent;
-	char			*copyvars, *var, *next;
+	struct options_entry	*o;
+	u_int			 size, idx;
+	const char		*value;
 
-	copyvars = next = xstrdup(vars);
-	while ((var = strsep(&next, " ")) != NULL) {
-		if ((envent = environ_find(srcenv, var)) == NULL)
-			environ_clear(dstenv, var);
+	o = options_get(oo, "update-environment");
+	if (o == NULL || options_array_size(o, &size) == -1)
+		return;
+	for (idx = 0; idx < size; idx++) {
+		value = options_array_get(o, idx);
+		if (value == NULL)
+			continue;
+		if ((envent = environ_find(src, value)) == NULL)
+			environ_clear(dst, value);
 		else
-			environ_set(dstenv, envent->name, "%s", envent->value);
+			environ_set(dst, envent->name, "%s", envent->value);
 	}
-	free(copyvars);
 }
 
 /* Push environment into the real environment - use after fork(). */

options-table.c

@@ -482,11 +482,10 @@ const struct options_table_entry options_table[] = {
 	},
 
 	{ .name = "update-environment",
-	  .type = OPTIONS_TABLE_STRING,
+	  .type = OPTIONS_TABLE_ARRAY,
 	  .scope = OPTIONS_TABLE_SESSION,
 	  .default_str = "DISPLAY SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID "
 	                 "SSH_CONNECTION WINDOWID XAUTHORITY"
-
 	},
 
 	{ .name = "visual-activity",

tmux.1

@@ -2869,19 +2869,15 @@ For how to specify
 see the
 .Ic message-command-style
 option.
-.It Ic update-environment Ar variables
-Set a space-separated string containing a list of environment variables to be
-copied into the session environment when a new session is created or an
-existing session is attached.
+.It Ic update-environment[] Ar variable
+Set list of environment variables to be copied into the session environment
+when a new session is created or an existing session is attached.
 Any variables that do not exist in the source environment are set to be
 removed from the session environment (as if
 .Fl r
 was given to the
 .Ic set-environment
 command).
-The default is
-"DISPLAY SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID SSH_CONNECTION WINDOWID
-XAUTHORITY".
 .It Xo Ic visual-activity
 .Op Ic on | off
 .Xc

tmux.h

@@ -1669,7 +1669,7 @@ void printflike(3, 4) environ_set(struct environ *, const char *, const char *,
 void	environ_clear(struct environ *, const char *);
 void	environ_put(struct environ *, const char *);
 void	environ_unset(struct environ *, const char *);
-void	environ_update(const char *, struct environ *, struct environ *);
+void	environ_update(struct options *, struct environ *, struct environ *);
 void	environ_push(struct environ *);
 void	environ_log(struct environ *, const char *);