From 41e8caee2a631ed6be47e47c36a05b53a3b2155c Mon Sep 17 00:00:00 2001
From: Steve Bennett <stevagewp@gmail.com>
Date: Fri, 23 Mar 2012 00:46:31 +1100
Subject: [PATCH] Fix #3786 by preventing user trying to circularise
 problematic shapes like figure-eights.

---
 net/systemeD/potlatch2/Toolbox.mxml         | 15 +++++++++++----
 net/systemeD/potlatch2/tools/Circularise.as |  9 +++++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/net/systemeD/potlatch2/Toolbox.mxml b/net/systemeD/potlatch2/Toolbox.mxml
index a58c97b0..c808e7b0 100644
--- a/net/systemeD/potlatch2/Toolbox.mxml
+++ b/net/systemeD/potlatch2/Toolbox.mxml
@@ -91,10 +91,11 @@
 		import flash.events.MouseEvent;
 		import net.systemeD.halcyon.connection.*;
 		import net.systemeD.halcyon.connection.actions.*;
+        import net.systemeD.halcyon.AttentionEvent;
 		import net.systemeD.potlatch2.controller.*;
 		import net.systemeD.potlatch2.tools.*;
 		import embedded.*;	// for FXG icons
-
+    
 		private var controller:EditController;
 
         [Bindable]
@@ -294,10 +295,16 @@
 
 		public function doCircularise():void {
 			var undo:CompositeUndoableAction = new CompositeUndoableAction("Make objects circular ");
-			for each (var way:Way in controller.state.selectedWays) {
-				Circularise.circularise(way, controller.map, undo.push);
+			try {
+				
+				for each (var way:Way in controller.state.selectedWays) {
+					Circularise.circularise(way, controller.map, undo.push);
+				}
+                MainUndoStack.getGlobalStack().addAction(undo);
+			} catch (e: Error) {
+			    var msg:String = e.message;
+			    controller.dispatchEvent(new AttentionEvent(AttentionEvent.ALERT, null, msg));
 			}
-			MainUndoStack.getGlobalStack().addAction(undo);
 		}
 
 		public function doSplit():void {
diff --git a/net/systemeD/potlatch2/tools/Circularise.as b/net/systemeD/potlatch2/tools/Circularise.as
index 88bf1e84..5abfb910 100644
--- a/net/systemeD/potlatch2/tools/Circularise.as
+++ b/net/systemeD/potlatch2/tools/Circularise.as
@@ -81,6 +81,11 @@ package net.systemeD.potlatch2.tools {
 				if (clockwise) {
 					if (a2>a1) { a2=a2-360; }
 					diff=a1-a2;
+					if (diff > 180) {
+						// If way crosses back on itself, we risk creating lots of extra nodes.
+						// (Bug 3786)
+						throw new Error ("This shape is too irregular. Sorry.");
+					}
 					if (diff>20) {
 						for (ang=a1-20; ang>a2+10; ang-=20) {
 						    insertNode(ang, i+1);
@@ -90,6 +95,9 @@ package net.systemeD.potlatch2.tools {
 				} else {
 					if (a1>a2) { a1=a1-360; }
 					diff=a2-a1;
+                    if (diff > 180) {
+                        throw new Error ("This shape is too irregular. Sorry.");
+                    }
 					if (diff>20) {
 						for (ang=a1+20; ang<a2-10; ang+=20) {
 						    insertNode(ang, i+1);
@@ -168,3 +176,4 @@ package net.systemeD.potlatch2.tools {
 		}
 	}
 }
+