sway: Problems with git master versions of json-c

Short version: It won’t compile out of the box. If do you change the code in order to compile it, it will crash whenever you use any key binding. I eventually decided to see if there were earlier tags of json-c that wouldn’t have this problem and it seems that even with the latest one, version 0.12.1, sway compiles and runs just fine. Maybe the maximum version of json-c with which sway will work should be indicated in README.

Long version: When compiling, you get type mismatch errors in five files, all involving json_object_array_length in for loops: sway/ipc-server.c: In function ‘ipc_client_handle_command’: sway/ipc-server.c:449:21: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare] for (int i = 0; i < json_object_array_length(request); i++) {

The five files are:

• sway/ipc-server.c
• swaybar/status_line.c
• swaybar/tray/tray.c
• swaygrab/json.c
• swaylock/main.c

The solution for that is very simple. Merely change the type of the counter variables from int to size_t.

On pressing keys, I’ve traced the problem to the line in ipc-server.c:

json_object_object_add(obj, "binding", sb_obj);

My guess is that the call to json_object_put(obj); later in the function frees the objects recursively and then sb_obj is used (or more likely freed, as the stdout error I get from glibc is *** Error in 'sway': corrupted double-linked list: ) later, causing an Earth-shattering kaboom.

Here’s the log file. I used Lynx because I couldn’t figure out how to upload a file with my usual browser (though, I know, Lynx should be be usual browser; with Lynx, all I had to do was ^Xe:e ~/.sway.log<Return>VGy:e #1<Return>p:wq) and I seem not to have been logged into to github, so it’s anonymous gist. Hmm. https://gist.github.com/anonymous/fe18bb44c7d40d5d63fbf15427e70fdc