Take Window special case into account for invalid layouts (#17598)

Change-Id: If736e0d35376f90dee33d93588351ef726a4635f

server/src/com/vaadin/server/ComponentSizeValidator.java

@@ -598,6 +598,12 @@ public class ComponentSizeValidator implements Serializable {
         if (parent == null) {
             return false;
         } else if (parent.getWidth() < 0) {
+            if (parent instanceof Window) {
+                // Window has some weird haxxors to support 100% children when
+                // window is -1
+                return false;
+            }
+
             return true;
         } else if (parent.getWidthUnits() == Unit.PERCENTAGE) {
             return isEffectiveUndefinedWidth(parent.getParent());
@@ -615,6 +621,12 @@ public class ComponentSizeValidator implements Serializable {
         if (parent == null) {
             return false;
         } else if (parent.getHeight() < 0) {
+            if (parent instanceof Window) {
+                // Window has some weird haxxors to support 100% children when
+                // window is -1
+                return false;
+            }
+
             return true;
         } else if (parent.getHeightUnits() == Unit.PERCENTAGE) {
             return isEffectiveUndefinedHeight(parent.getParent());