Window: fix missing returns after sending an error

In three places we continue control flow despite recognizing erroneous
arguments and informing the client of such. This leads to crashes due to
assertion failures.

 river/Window.zig | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/river/Window.zig b/river/Window.zig
index 3cbc177..3ce5615 100644
--- a/river/Window.zig
+++ b/river/Window.zig
@@ -514,6 +514,7 @@ fn handleRequest(
             if (!server.wm.ensureWindowing()) return;
             if (args.width < 0 or args.height < 0) {
                 window_v1.postError(.invalid_dimensions, "dimensions must be greater than or equal to 0 ");
+                return;
             }
             wm_requested.dimensions = .{
                 .width = @intCast(args.width),
@@ -540,6 +541,7 @@ fn handleRequest(
             if (!server.wm.ensureRendering()) return;
             if (args.width < 0) {
                 window_v1.postError(.invalid_border, "border width must be greater than or equal to 0 ");
+                return;
             }
             rendering_requested.border = .{
                 .edges = args.edges,
@@ -619,6 +621,7 @@ fn handleRequest(
             if (!server.wm.ensureRendering()) return;
             if (args.width < 0 or args.height < 0) {
                 window_v1.postError(.invalid_clip_box, "width/height must be greater than or equal to 0 ");
+                return;
             }
             rendering_requested.clip = .{
                 .x = args.x,