From 0570c227325baec47888a96fc68bff6551009116 Mon Sep 17 00:00:00 2001
From: Jon Evans <jon@craftyjon.com>
Date: Sat, 27 Nov 2021 09:08:23 -0500
Subject: [PATCH] Use point collision test for zero-length segments

SEG::SquaredDistance( SEG& ) does not do the right thing
for segments with zero length at the moment.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/9791
---
 libs/kimath/include/geometry/shape_segment.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libs/kimath/include/geometry/shape_segment.h b/libs/kimath/include/geometry/shape_segment.h
index 5a5f833ee4..ac3ddabdf3 100644
--- a/libs/kimath/include/geometry/shape_segment.h
+++ b/libs/kimath/include/geometry/shape_segment.h
@@ -78,6 +78,9 @@ public:
     bool Collide( const SEG& aSeg, int aClearance = 0, int* aActual = nullptr,
                   VECTOR2I* aLocation = nullptr ) const override
     {
+        if( aSeg.A == aSeg.B )
+            return Collide( aSeg.A, aClearance, aActual, aLocation );
+
         int min_dist = ( m_width + 1 ) / 2 + aClearance;
         ecoord dist_sq = m_seg.SquaredDistance( aSeg );