From 78c73bcde985e50b2c0f27b34e03e86736a37aa1 Mon Sep 17 00:00:00 2001
From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Fri, 23 Apr 2021 20:09:28 -0700
Subject: [PATCH] anticipate a -2 return from seg_cmp indicating an error

Related to #1801.
---
 lib/ortho/ortho.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/ortho/ortho.c b/lib/ortho/ortho.c
index becbf37a0..7926b5929 100644
--- a/lib/ortho/ortho.c
+++ b/lib/ortho/ortho.c
@@ -756,9 +756,11 @@ add_edges_in_G(channel* cp)
     for(x=0;x+1<size;x++) {
 	for(y=x+1;y<size;y++) {
 	    int cmp = seg_cmp(seg_list[x],seg_list[y]);
-	    if (cmp > 0) {
+	    if (cmp == -2) {
+		return -1;
+	    } else if (cmp > 0) {
 		insert_edge(G,x,y);
-	    } else if (cmp < 0) {
+	    } else if (cmp == -1) {
 		insert_edge(G,y,x);
 	    }
 	}
@@ -868,6 +870,9 @@ decide_point(pair *ret, segment* si, segment* sj, int dir1, int dir2)
 	assert(0); /* FIXME */
     else {
 	temp = seg_cmp(np1, np2);
+	if (temp == -2) {
+	    return -1;
+	}
 	prec = propagate_prec(np1, temp, ans+1, 1-dir1);
     }
 		
-- 
2.50.1