Prevent memory errors on home page

src/home.zig

@@ -72,6 +72,8 @@ fn fetchThread(state: *AppState) !void {
                 }
             }
         }
+        state.home_screen_state.mutex.lock();
+        defer state.home_screen_state.mutex.unlock();
         if (state.home_screen_state.suggestions.len > 0) {
             for (state.home_screen_state.suggestions) |suggestion| {
                 allocator.free(suggestion.id);
@@ -94,8 +96,14 @@ pub fn render(state: *AppState) !void {
     }
 
     while (raylib.GetCharPressed()) |char| {
-        hs.station_name.appendAssumeCapacity(@intCast(char));
+        if (hs.station_name.items.len < hs.station_name_max_len) {
+            hs.station_name.appendAssumeCapacity(@intCast(char));
+        }
     }
+
+    state.home_screen_state.mutex.lock();
+    defer state.home_screen_state.mutex.unlock();
+
     while (raylib.GetKeyPressed()) |key| {
         switch (key) {
             rl.KEY_BACKSPACE => {

src/main.zig

@@ -32,6 +32,7 @@ pub fn main() !void {
         .ns_font = raylib.LoadFontEx("./private/ns.ttf", 64, cp, cp_cnt),
         .home_screen_state = .{
             .station_name = std.ArrayListUnmanaged(u8).initBuffer(&station_name_buffer),
+            .station_name_max_len = station_name_buffer.len - 1,
         },
         .departure_screen_state = .{
             .platform = std.ArrayListUnmanaged(u8).initBuffer(&platform_buffer),

src/state.zig

@@ -13,7 +13,9 @@ pub const HSSuggestion = struct {
 };
 
 pub const HomeScreenState = struct {
+    mutex: std.Thread.Mutex = .{},
     station_name: std.ArrayListUnmanaged(u8),
+    station_name_max_len: usize,
     fetch_thread: ?std.Thread = null,
     suggestions: []HSSuggestion = &.{},
     selection_idx: i8 = 0,