On execwm, we should properly release resources before exec'ing into a

new window manager; so allow CWM_EXEC_WM to assign new wm to wm_argv and
pass through cwm_status (now EXECWM) so that x_teardown() gets called
before exec'ing the new window manager.  Removes the need for a separate
x_restart() now, using new wm_argv; and consolidates errno for execvp.

calmwm.c

@@ -46,12 +46,12 @@ struct screen_ctx_q		 Screenq = TAILQ_HEAD_INITIALIZER(Screenq);
 int				 HasRandr, Randr_ev;
 struct conf			 Conf;
 const char			*homedir;
+char				*wm_argv;
 volatile sig_atomic_t		 cwm_status;
 
 static void	sighdlr(int);
 static int	x_errorhandler(Display *, XErrorEvent *);
 static void	x_init(const char *);
-static void	x_restart(char **);
 static void	x_teardown(void);
 static int	x_wmerrorhandler(Display *, XErrorEvent *);
 
@@ -60,7 +60,6 @@ main(int argc, char **argv)
 {
 	const char	*conf_file = NULL;
 	char		*conf_path, *display_name = NULL;
-	char		**cwm_argv;
 	int		 ch;
 	struct passwd	*pw;
 
@@ -68,7 +67,7 @@ main(int argc, char **argv)
 		warnx("no locale support");
 	mbtowc(NULL, NULL, MB_CUR_MAX);
 
-	cwm_argv = argv;
+	wm_argv = u_argv(argv);
 	while ((ch = getopt(argc, argv, "c:d:")) != -1) {
 		switch (ch) {
 		case 'c':
@@ -117,8 +116,8 @@ main(int argc, char **argv)
 	while (cwm_status == CWM_RUNNING)
 		xev_process();
 	x_teardown();
-	if (cwm_status == CWM_RESTART)
-		x_restart(cwm_argv);
+	if (cwm_status == CWM_EXECWM)
+		u_exec(wm_argv);
 
 	return(0);
 }
@@ -145,13 +144,6 @@ x_init(const char *dpyname)
 		screen_init(i);
 }
 
-static void
-x_restart(char **args)
-{
-	(void)setsid();
-	(void)execvp(args[0], args);
-}
-
 static void
 x_teardown(void)
 {

calmwm.h

@@ -88,7 +88,7 @@
 
 #define CWM_QUIT		0x0000
 #define CWM_RUNNING		0x0001
-#define CWM_RESTART		0x0002
+#define CWM_EXECWM		0x0002
 
 union arg {
 	char	*c;
@@ -334,6 +334,7 @@ extern Display				*X_Dpy;
 extern Time				 Last_Event_Time;
 extern struct screen_ctx_q		 Screenq;
 extern struct conf			 Conf;
+extern char				*wm_argv;
 extern const char			*homedir;
 extern int				 HasRandr, Randr_ev;
 
@@ -581,6 +582,7 @@ void 			 xu_ewmh_handle_net_wm_state_msg(struct client_ctx *,
 void 			 xu_ewmh_set_net_wm_state(struct client_ctx *);
 void 			 xu_ewmh_restore_net_wm_state(struct client_ctx *);
 
+char			*u_argv(char * const *);
 void			 u_exec(char *);
 void			 u_spawn(char *);
 

conf.c

@@ -400,7 +400,7 @@ static const struct {
 	{ "vmaximize", kbfunc_client_toggle_vmaximize, CWM_WIN, {0} },
 	{ "hmaximize", kbfunc_client_toggle_hmaximize, CWM_WIN, {0} },
 	{ "freeze", kbfunc_client_toggle_freeze, CWM_WIN, {0} },
-	{ "restart", kbfunc_cwm_status, 0, {.i = CWM_RESTART} },
+	{ "restart", kbfunc_cwm_status, 0, {.i = CWM_EXECWM} },
 	{ "quit", kbfunc_cwm_status, 0, {.i = CWM_QUIT} },
 	{ "exec", kbfunc_exec, 0, {.i = CWM_EXEC_PROGRAM} },
 	{ "exec_wm", kbfunc_exec, 0, {.i = CWM_EXEC_WM} },

kbfunc.c

@@ -325,8 +325,9 @@ kbfunc_exec(struct client_ctx *cc, union arg *arg)
 			u_spawn(mi->text);
 			break;
 		case CWM_EXEC_WM:
-			u_exec(mi->text);
-			warn("%s", mi->text);
+			cwm_status = CWM_EXECWM;
+			free(wm_argv);
+			wm_argv = xstrdup(mi->text);
 			break;
 		default:
 			errx(1, "kb_func: egad, cmd changed value!");

util.c

@@ -31,15 +31,12 @@
 
 #include "calmwm.h"
 
-#define MAXARGLEN 20
-
 void
 u_spawn(char *argstr)
 {
 	switch (fork()) {
 	case 0:
 		u_exec(argstr);
-		err(1, "%s", argstr);
 		break;
 	case -1:
 		warn("fork");
@@ -51,8 +48,10 @@ u_spawn(char *argstr)
 void
 u_exec(char *argstr)
 {
+#define MAXARGLEN 20
 	char	*args[MAXARGLEN], **ap = args;
 	char	**end = &args[MAXARGLEN - 1], *tmp;
+	char	*s = argstr;
 
 	while (ap < end && (*ap = strsep(&argstr, " \t")) != NULL) {
 		if (**ap == '\0')
@@ -75,8 +74,33 @@ u_exec(char *argstr)
 			}
 		}
 	}
-
 	*ap = NULL;
+
 	(void)setsid();
 	(void)execvp(args[0], args);
+	err(1, "%s", s);
+}
+
+char *
+u_argv(char * const *argv)
+{
+	size_t	 siz = 0;
+	int	 i;
+	char	*p;
+
+	if (argv == 0)
+		return(NULL);
+
+	for (i = 0; argv[i]; i++)
+		siz += strlen(argv[i]) + 1;
+	if (siz == 0)
+		return(NULL);
+
+	p = xmalloc(siz);
+	strlcpy(p, argv[0], siz);
+	for (i = 1; argv[i]; i++) {
+		strlcat(p, " ", siz);
+		strlcat(p, argv[i], siz);
+	}
+	return(p);
 }