Prevent sway from duplicating on a failed fork

Also remove a useless `sway_log` and replace it with a pipe

1 files changed, 32 insertions, 2 deletions

diff --git a/sway/config.c b/sway/config.c
index c8432a2a..ae09d4f8 100644
--- a/sway/config.c
+++ b/sway/config.c
@@ -912,8 +912,16 @@ void merge_output_config(struct output_config *dst, struct output_config *src) {
 }
 
 static void invoke_swaybar(struct bar_config *bar) {
+        // Pipe to communicate errors
+        int filedes[2];
+        if (pipe(filedes) == -1) {
+                sway_log(L_ERROR, "Pipe setup failed! Cannot fork into bar");
+                return;
+        }
+
         bar->pid = fork();
         if (bar->pid == 0) {
+                close(filedes[0]);
                 if (!bar->swaybar_command) {
                         char *const cmd[] = {
                                 "swaybar",
@@ -922,14 +930,20 @@ static void invoke_swaybar(struct bar_config *bar) {
                                 NULL,
                         };
 
+                        close(filedes[1]);
                         execvp(cmd[0], cmd);
+                        _exit(EXIT_SUCCESS);
                 } else {
                         // run custom swaybar
                         int len = strlen(bar->swaybar_command) + strlen(bar->id) + 5;
                         char *command = malloc(len * sizeof(char));
                         if (!command) {
-                                sway_log(L_ERROR, "Unable to allocate swaybar command string");
-                                return;
+                                const char msg[] = "Unable to allocate swaybar command string";
+                                int len = sizeof(msg);
+                                write(filedes[1], &len, sizeof(int));
+                                write(filedes[1], msg, len);
+                                close(filedes[1]);
+                                _exit(EXIT_FAILURE);
                         }
                         snprintf(command, len, "%s -b %s", bar->swaybar_command, bar->id);
 
@@ -940,10 +954,26 @@ static void invoke_swaybar(struct bar_config *bar) {
                                 NULL,
                         };
 
+                        close(filedes[1]);
                         execvp(cmd[0], cmd);
                         free(command);
+                        _exit(EXIT_SUCCESS);
+                }
+        }
+        close(filedes[0]);
+        int len;
+        if(read(filedes[1], &len, sizeof(int)) == sizeof(int)) {
+                char *buf = malloc(len);
+                if(!buf) {
+                        sway_log(L_ERROR, "Cannot allocate error string");
+                        return;
+                }
+                if(read(filedes[1], buf, len)) {
+                        sway_log(L_ERROR, "%s", buf);
                 }
+                free(buf);
         }
+        close(filedes[1]);
 }
 
 static void terminate_swaybar(pid_t pid) {