IndexedFacetDistance: Avoid crash on Inf inputs

Fixes #821
libgeos · Feb 28, 2023 · aa4503f · aa4503f
1 parent 52740ec
commit aa4503f
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diff --git a/NEWS b/NEWS
@@ -3,6 +3,7 @@ Changes in 3.9.5
 
 - Bug fixes / improvements:
   - GEOSUnaryUnion: Fix crash on collection containing empty point (GH-830, Dan Baston)
+  - IndexedFacetDistance: Fix crash with Inf coordinates (GH-821, Dan Baston)
 
 
 Changes in 3.9.4

diff --git a/src/operation/distance/FacetSequence.cpp b/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);

diff --git a/tests/unit/operation/distance/IndexedFacetDistanceTest.cpp b/tests/unit/operation/distance/IndexedFacetDistanceTest.cpp
@@ -33,6 +33,8 @@
 #define M_PI 3.14159265358979323846
 #endif
 
+using geos::operation::distance::IndexedFacetDistance;
+
 namespace tut {
 //
 // Test Group
@@ -366,6 +368,31 @@ 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 seq = geos::detail::make_unique<geos::geom::CoordinateArraySequence>(std::move(pts));
+
+    auto ls = _factory->createLineString(std::move(seq));
+    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: