RepeatedPointRemover: Avoid reading invalidated reference (#762)

Fixes #759
libgeos · Dec 8, 2022 · d463bcb · d463bcb
1 parent e692362
commit d463bcb
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Showing 2 changed files with 13 additions and 1 deletion.
diff --git a/src/operation/valid/RepeatedPointRemover.cpp b/src/operation/valid/RepeatedPointRemover.cpp
@@ -211,13 +211,14 @@ class RepeatedPointCoordinateOperation : public CoordinateOperation
 
         // End points for comparison and sequence repair
         const Coordinate& origEndCoord = coordinates->back();
-        const Coordinate& filtEndCoord = filtCoords->back();
 
         // Fluff up overly small filtered outputs
         if(filtCoords->size() < minLength) {
             filtCoords->add(origEndCoord);
         }
 
+        const Coordinate& filtEndCoord = filtCoords->back();
+
         // We stripped the last point, let's put it back on
         if (!origEndCoord.equals2D(filtEndCoord)) {
             // If the end of the filtered coordinates is within

diff --git a/tests/unit/capi/GEOSRemoveRepeatedPointsTest.cpp b/tests/unit/capi/GEOSRemoveRepeatedPointsTest.cpp
@@ -45,6 +45,17 @@ void object::test<1>
     ensure_geometry_equals(geom2_, expected_);
 }
 
+// https://github.com/libgeos/geos/issues/759
+template<>
+template<>
+void object::test<2>
+()
+{
+    geom1_ = GEOSGeomFromWKT("POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))");
+    result_ = GEOSRemoveRepeatedPoints(geom1_, 2.0);
+
+    ensure(result_ == nullptr);
+}
 
 
 } // namespace tut