cli/gtk: clean ups and better error handling in GTK new-window IPC

src/apprt/gtk/ipc/new_window.zig

@@ -41,6 +41,12 @@ pub fn openNewWindow(alloc: Allocator, target: apprt.ipc.Target, value: apprt.ip
             .ReleaseFast, .ReleaseSmall => .{ "com.mitchellh.ghostty", "/com/mitchellh/ghostty" },
         },
     };
+    defer {
+        switch (target) {
+            .class => alloc.free(object_path),
+            .detect => {},
+        }
+    }
 
     if (gio.Application.idIsValid(bus_name.ptr) == 0) {
         try stderr.print("D-Bus bus name is not valid: {s}\n", .{bus_name});
@@ -80,7 +86,7 @@ pub fn openNewWindow(alloc: Allocator, target: apprt.ipc.Target, value: apprt.ip
         // Initialize our builder to build up our parameters
         var builder: glib.VariantBuilder = undefined;
         builder.init(builder_type);
-        errdefer builder.unref();
+        errdefer builder.clear();
 
         // action
         if (value.arguments == null) {
@@ -96,6 +102,7 @@ pub fn openNewWindow(alloc: Allocator, target: apprt.ipc.Target, value: apprt.ip
 
             var parameters: glib.VariantBuilder = undefined;
             parameters.init(av);
+            errdefer parameters.clear();
 
             if (value.arguments) |arguments| {
                 // If `-e` was specified on the command line, the first
@@ -108,6 +115,7 @@ pub fn openNewWindow(alloc: Allocator, target: apprt.ipc.Target, value: apprt.ip
 
                     var command: glib.VariantBuilder = undefined;
                     command.init(as);
+                    errdefer command.clear();
 
                     for (arguments) |argument| {
                         command.add("s", argument.ptr);

src/apprt/ipc.zig

@@ -5,6 +5,9 @@ const Allocator = std.mem.Allocator;
 const assert = std.debug.assert;
 
 pub const Errors = error{
+    /// The IPC failed. If a function returns this error, it's expected that
+    /// an a more specific error message will have been written to stderr (or
+    /// otherwise shown to the user in an appropriate way).
     IPCFailed,
 };
 
@@ -38,8 +41,6 @@ pub const Target = union(Key) {
         return .{
             .key = @as(Key, self),
             .value = switch (self) {
-                .release => .{ .release = {} },
-                .debug => .{ .debug = {} },
                 .class => |class| .{ .class = class.ptr },
                 .detect => .{ .detect = {} },
             },
@@ -68,6 +69,11 @@ pub const Action = union(enum) {
     new_window: NewWindow,
 
     pub const NewWindow = struct {
+        /// A list of command arguments to launch in the new window. If this is
+        /// `null` the command configured in the config or the user's default
+        /// shell should be launched.
+        ///
+        /// It is an error for this to be non-`null`, but zero length.
         arguments: ?[][:0]const u8,
 
         pub const C = extern struct {