From 1803cd216ae6b5adb6410b5e13285b0a7fc04526 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ju=CC=88rg=20Lehni?= <juerg@scratchdisk.com>
Date: Mon, 5 Jan 2015 00:42:00 +0100
Subject: [PATCH] Handle empty paths in Path#join()

Closes #516
---
 src/path/Path.js | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/path/Path.js b/src/path/Path.js
index c02a2a0b..9f3805b5 100644
--- a/src/path/Path.js
+++ b/src/path/Path.js
@@ -1250,7 +1250,8 @@ var Path = PathItem.extend(/** @lends Path# */{
      * Joins the path with the specified path, which will be removed in the
      * process.
      *
-     * @param {Path} path
+     * @param {Path} path the path to join this path with
+     * @return {Path} the joined path
      *
      * @example {@paperscript}
      * // Joining two paths:
@@ -1316,19 +1317,20 @@ var Path = PathItem.extend(/** @lends Path# */{
             var segments = path._segments,
                 last1 = this.getLastSegment(),
                 last2 = path.getLastSegment();
-            if (last1._point.equals(last2._point))
+            if (!last2) // an empty path?
+                return this;
+            if (last1 && last1._point.equals(last2._point))
                 path.reverse();
-            var first1,
-                first2 = path.getFirstSegment();
-            if (last1._point.equals(first2._point)) {
+            var first2 = path.getFirstSegment();
+            if (last1 && last1._point.equals(first2._point)) {
                 last1.setHandleOut(first2._handleOut);
                 this._add(segments.slice(1));
             } else {
-                first1 = this.getFirstSegment();
-                if (first1._point.equals(first2._point))
+                var first1 = this.getFirstSegment();
+                if (first1 && first1._point.equals(first2._point))
                     path.reverse();
                 last2 = path.getLastSegment();
-                if (first1._point.equals(last2._point)) {
+                if (first1 && first1._point.equals(last2._point)) {
                     first1.setHandleIn(last2._handleIn);
                     // Prepend all segments from path except the last one
                     this._add(segments.slice(0, segments.length - 1), 0);
@@ -1351,6 +1353,7 @@ var Path = PathItem.extend(/** @lends Path# */{
             last.remove();
             this.setClosed(true);
         }
+        return this;
     },