From 4b15855b2f9f13d3cfbbb1113c7fd66ca9a0c3f6 Mon Sep 17 00:00:00 2001
From: sk89q <the.sk89q@gmail.com>
Date: Wed, 6 Feb 2013 17:19:09 -0800
Subject: [PATCH] Revert "Removed parents from regions."

Removal of parents will make upgrading extremely difficult and so consider them pending for the itme being.

This reverts commit df54d4de91d0c5bd30d3421010b6a0248b0cf546.
---
 .../com/sk89q/worldguard/region/Region.java   | 41 +++++++++++++++++++
 .../sk89q/worldguard/region/RegionTest.java   | 22 ++++++++++
 2 files changed, 63 insertions(+)

diff --git a/src/main/java/com/sk89q/worldguard/region/Region.java b/src/main/java/com/sk89q/worldguard/region/Region.java
index 23d1c0a6..e17cc9bb 100644
--- a/src/main/java/com/sk89q/worldguard/region/Region.java
+++ b/src/main/java/com/sk89q/worldguard/region/Region.java
@@ -40,6 +40,7 @@ public class Region implements Comparable<Region> {
     private final String id;
     private IndexableShape shape;
     private int priority = 0;
+    private Region parent;
     private Map<String, Attribute> attributes = new HashMap<String, Attribute>();
 
     /**
@@ -105,6 +106,46 @@ public int getPriority() {
     public void setPriority(int priority) {
         this.priority = priority;
     }
+
+    /**
+     * Get the parent of the region. Parents can determine how multiple overlapping
+     * regions are handled in regards to some flags, but it is dependent on the flag.
+     *
+     * @return parent region or null
+     */
+    public Region getParent() {
+        return parent;
+    }
+
+    /**
+     * Set the parent of this region.
+     *
+     * @see #getParent() for an explanation of parents
+     * @param parent the new parent, or null
+     * @throws IllegalArgumentException when circular inheritance is detected
+     */
+    public synchronized void setParent(Region parent) throws IllegalArgumentException {
+        if (parent == null) {
+            this.parent = null;
+        } else {
+            if (parent == this) {
+                throw new IllegalArgumentException(
+                        "Circular region inheritance detected");
+            }
+
+            Region p = parent.getParent();
+            while (p != null) {
+                if (p == this) {
+                    throw new IllegalArgumentException(
+                            "Circular region inheritance detected");
+                }
+
+                p = p.getParent();
+            }
+
+            this.parent = parent;
+        }
+    }
     
     /**
      * Set an attribute to this region.
diff --git a/src/test/java/com/sk89q/worldguard/region/RegionTest.java b/src/test/java/com/sk89q/worldguard/region/RegionTest.java
index 1fa04ff4..8cf0100f 100644
--- a/src/test/java/com/sk89q/worldguard/region/RegionTest.java
+++ b/src/test/java/com/sk89q/worldguard/region/RegionTest.java
@@ -60,6 +60,28 @@ public void testCompareTo() {
         assertEquals(regionB.compareTo(regionB), 0);
     }
 
+    @Test
+    public void testSetParent() {
+        // Test self setting
+        Region regionA = new Region("A", mock(IndexableShape.class));
+        thrown.expect(IllegalArgumentException.class);
+        regionA.setParent(regionA);
+        
+        // Test regular setting
+        Region child = new Region("A", mock(IndexableShape.class));
+        Region parent = new Region("B", mock(IndexableShape.class));
+        child.setParent(parent);
+        assertEquals(child.getParent(), parent);
+        assertEquals(parent.getParent(), null);
+        
+        // Test circular
+        child = new Region("A", mock(IndexableShape.class));
+        parent = new Region("B", mock(IndexableShape.class));
+        child.setParent(parent);
+        thrown.expect(IllegalArgumentException.class);
+        parent.setParent(child);
+    }
+
     @Test
     public void testGetPriority() {
         Region regionA = new Region("A", mock(IndexableShape.class));