IndexedFacetDistance: Avoid crash on Inf inputs

Fixes #821

NEWS.md

@@ -45,6 +45,7 @@ xxxx-xx-xx
   - GEOSUnaryUnion: Fix crash on collection containing empty point (GH-830, Dan Baston)
   - GEOSBuffer: Fix crash with Inf coordinates (GH-822, Dan Baston)
   - GEOSSTRtree_iterate: Do not return removed items (GH-833, Dan Baston)
+  - IndexedFacetDistance: Fix crash with Inf coordinates (GH-821, Dan Baston)
 
 
 ## Changes in 3.11.0

src/operation/distance/FacetSequence.cpp

@@ -128,7 +128,7 @@ FacetSequence::computeDistancePointLine(const Coordinate& pt,
         const Coordinate& q0 = facetSeq.pts->getAt(i);
         const Coordinate& q1 = facetSeq.pts->getAt(i + 1);
         double dist = Distance::pointToSegment(pt, q0, q1);
-        if(dist < minDistance) {
+        if(dist < minDistance || (locs != nullptr && locs->empty())) {
             minDistance = dist;
             if (locs != nullptr) {
                 updateNearestLocationsPointLine(pt, facetSeq, i, q0, q1, locs);

tests/unit/operation/distance/IndexedFacetDistanceTest.cpp

@@ -32,6 +32,8 @@
 #define M_PI 3.14159265358979323846
 #endif
 
+using geos::operation::distance::IndexedFacetDistance;
+
 namespace tut {
 //
 // Test Group
@@ -382,6 +384,29 @@ void object::test<11>
     catch (const GEOSException&) { }
 }
 
+// Test with Inf coords
+template<>
+template<>
+void object::test<12>()
+{
+    auto g1 = _wktreader.read("POINT (0 0)");
+    auto g2 = _wktreader.read("LINESTRING (3 Inf, 5 Inf)");
+
+    IndexedFacetDistance ifd1(g1.get());
+
+    auto pts = ifd1.nearestPoints(g2.get());
+    ensure_equals(pts->size(), 2u);
+
+    auto ls = _factory->createLineString(std::move(pts));
+    ls->normalize();
+
+    const auto& normPts = *ls->getCoordinatesRO();
+
+    ensure_equals(normPts.getX(0), 0);
+    ensure_equals(normPts.getY(0), 0);
+    ensure_equals(normPts.getY(1), geos::DoubleInfinity);
+}
+
 
 
 // TODO: finish the tests by adding: