commands: Gracefully handle empty commands.

Before this patch sway would proceed into find_handler which would cause
a crash trying to parse a NULL string.

This could be triggered via e.g. `i3-msg -s $(sway --get-socketpath)`.

1 files changed, 5 insertions, 0 deletions

diff --git a/sway/commands.c b/sway/commands.c
index 5afddc4a..eb77c172 100644
--- a/sway/commands.c
+++ b/sway/commands.c
@@ -1178,6 +1178,11 @@ enum cmd_status handle_command(char *_exec) {
                         // Split commands
                         cmd = argsep(&cmdlist, ",");
                         cmd += strspn(cmd, whitespace);
+                        if (strcmp(cmd, "") == 0) {
+                                sway_log(L_INFO, "Ignoring empty command.");
+                                continue;
+                        }
+
                         sway_log(L_INFO, "Handling command '%s'", cmd);
                         //TODO better handling of argv
                         int argc;