From 738cc4c214d8c565c94371e69707283bac4d14b9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=BCrg=20Lehni?= <juerg@scratchdisk.com>
Date: Sun, 20 Sep 2015 15:29:54 +0200
Subject: [PATCH] Yet another improvement in multiple interseections boolean
 code.

This appears to be the one. The only remaining failing cases seem to be linked to getting the same intersection twice now!

Relates to #787
---
 src/path/PathItem.Boolean.js | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/src/path/PathItem.Boolean.js b/src/path/PathItem.Boolean.js
index 0f222978..367340f8 100644
--- a/src/path/PathItem.Boolean.js
+++ b/src/path/PathItem.Boolean.js
@@ -573,9 +573,13 @@ PathItem.inject(new function() {
                     : !ignoreOther
                             // We need to get the intersection on the segment,
                             // not on inter, since they're only linked up
-                            // through _next there!
-                            && getIntersection(seg._intersection, null, true)
-                        || inter._next != prev // Prevent circular loops
+                            // through _next there. But do not check that
+                            // intersection in the first call to
+                            // getIntersection() (prev == null), since we'd go
+                            // back to the originating segment.
+                            && (prev || seg._intersection !== inter._intersection)
+                            && getIntersection(seg._intersection, inter, true)
+                        || inter._next !== prev // Prevent circular loops
                             && getIntersection(inter._next, inter, false);
         }
         for (var i = 0, l = segments.length; i < l; i++) {
@@ -591,20 +595,19 @@ PathItem.inject(new function() {
                 var inter = seg._intersection;
                 // Once we started a chain, see if there are multiple
                 // intersections, and if so, pick the best one:
-                if (window.reportSegments && added && inter) {
+                if (inter && added && window.reportSegments) {
                     console.log('Before getIntersection(), seg: '
-                            + seg._path._id + '.' +seg._index);
+                            + inter._segment._path._id + '.'
+                            + inter._segment._index);
                 }
                 inter = added && getIntersection(inter) || inter;
                 // A switched intersection means we may have changed the segment
-                if (inter) {
-                    seg = inter._intersection._segment;
-                    if (window.reportSegments && added) {
-                        console.log('After getIntersection(), seg: '
-                                + seg._path._id + '.' +seg._index);
-                    }
-                }
                 // Point to the other segment in the selected intersection.
+                if (inter && added && window.reportSegments) {
+                    console.log('After getIntersection(), seg: '
+                            + inter._segment._path._id + '.'
+                            + inter._segment._index);
+                }
                 var other = inter && inter._segment;
                 if (added && (seg === start || seg === otherStart)) {
                     // We've come back to the start, bail out as we're done.