Add check while calculating min size to prevent goofy situations

internal/system/hierarchy.go

@@ -341,15 +341,21 @@ func (this *Hierarchy) drawBackgroundPart (canvas.Canvas) {
 	// if so, windows should be transparent if the color has transparency
 }
 
+// var minimumSizeCount = 0
 func (this *Hierarchy) doMinimumSize () {
 	this.minimumClean = true
+	// println("doMinimumSize", minimumSizeCount)
+	// minimumSizeCount ++
 
+	previousMinimumSize := this.minimumSize
 	this.minimumSize = image.Point { }
 	if this.root != nil {
 		this.minimumSize = this.root.minimumSize()
 	}
 
+	if previousMinimumSize != this.minimumSize {
 		this.link.NotifyMinimumSizeChange()
+	}
 }
 
 func (this *Hierarchy) newStyleApplicator () *styleApplicator {

internal/util/util.go

@@ -83,6 +83,7 @@ func NewMemo[T any] (update func () T) Memo[T] {
 func (this *Memo[T]) Value () T {
 	if !this.valid {
 		this.cache = this.update()
+		this.valid = true
 	}
 	return this.cache
 }