BepInEx.OptimizeIMGUI Nested ExpandHeight in Vertical Group

[JustAGuest4168]

When nesting Vertical and Horizontal Groups, I discovered an issue with a Button with ExpandHeight(true) inside a Horizontal Group nested inside another Vertical Group with ExpandHeight(false) causing the Vertical Groups ExpandHeight(false) to be negated. Screenshots of with and without BepInEx.OptimizeIMGUI and condensed sample code below.

Without BepInEx.OptimizeIMGUI (Correct):

With BepInEx.OptimizeIMGUI (Incorrect):

Condensed Sample code:

public class NewBehaviourScript : MonoBehaviour
{
    private Rect uiWindow2 = new Rect(UnityEngine.Screen.width / 2 + 20, 20, 120, 400);
    private void OnGUI()
    {
        uiWindow2 = GUILayout.Window(34566, uiWindow2, DisplayUIWindowX, "TEST");
    }
    private void DisplayUIWindowX(int windowId)
    {
        GUILayout.BeginVertical(GUILayout.ExpandWidth(true), GUILayout.ExpandHeight(true));
        {
            //Header
            GUILayout.BeginVertical("box", GUILayout.ExpandWidth(true), GUILayout.ExpandHeight(false));
            {
                //Toolbar
                {
                    GUILayout.BeginHorizontal(GUILayout.ExpandHeight(false));
                    {
                        //Header
                        GUILayout.Label("TEST", GUILayout.ExpandWidth(true));

                        //Options
                        if (GUILayout.Button("O", GUILayout.ExpandWidth(false), GUILayout.ExpandHeight(true)))
                        {
                        }
                    }
                    GUILayout.EndHorizontal();

                    //Options
                }
            }
            GUILayout.EndVertical();

            //Content
            GUILayout.BeginVertical("box", GUILayout.ExpandWidth(true), GUILayout.ExpandHeight(true));
            {
                //Abstract
                //this.DisplayUIWindowBase();
                GUILayout.FlexibleSpace();
            }
            GUILayout.EndVertical();

            //Info
            GUILayout.BeginVertical("box", GUILayout.ExpandWidth(true), GUILayout.ExpandHeight(false));
            {
                GUILayout.BeginHorizontal();
                {
                    GUILayout.Label("Info: " + "", GUILayout.ExpandWidth(true));
                    if (GUILayout.Button("Clear", GUILayout.ExpandWidth(false), GUILayout.ExpandHeight(true)))
                    {
                        //info = "";
                    }
                }
                GUILayout.EndHorizontal();
            }
            GUILayout.EndVertical();
        }
        GUILayout.EndVertical();

        GUI.DragWindow();
    }
}

[ManlyMarco]

It looks like it's not an easy thing to fix without straight up disabling the feature, so unfortunately I'll have to mark this as a nofix. If anyone is able to fix this I'll be happy to merge a PR.

For now I added a warning to the readme ba276fe