Merge branch 'empty-crash-unary-union' of https://github.com/sir-sigu…

…rd/libgeos into sir-sigurd-empty-crash-unary-union
beixuewei · Sep 24, 2018 · d5141be · d5141be
2 parents 52c516f + 2af4f06
commit d5141be
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Showing 3 changed files with 28 additions and 1 deletion.
diff --git a/src/operation/union/UnaryUnionOp.cpp b/src/operation/union/UnaryUnionOp.cpp
@@ -93,7 +93,9 @@ UnaryUnionOp::Union()
        */
       unionLines.reset( CascadedUnion::Union( lines.begin(),
                                               lines.end()   ) );
-      unionLines = unionNoOpt(*unionLines);
+      if (unionLines.get()) {
+          unionLines = unionNoOpt(*unionLines);
+      }
   }
 
   GeomPtr unionPolygons;

diff --git a/tests/unit/capi/GEOSUnaryUnionTest.cpp b/tests/unit/capi/GEOSUnaryUnionTest.cpp
@@ -207,5 +207,18 @@ namespace tut
 
     }
 
+    // Self-union an empty linestring
+    template<>
+    template<>
+    void object::test<10>()
+    {
+        geom1_ = GEOSGeomFromWKT("LINESTRING EMPTY");
+        ensure( nullptr != geom1_ );
+
+        geom2_ = GEOSUnaryUnion(geom1_);
+        ensure( nullptr != geom2_ );
+
+        ensure_equals(toWKT(geom2_), std::string("GEOMETRYCOLLECTION EMPTY"));
+    }
 } // namespace tut
 
diff --git a/tests/unit/operation/union/UnaryUnionOpTest.cpp b/tests/unit/operation/union/UnaryUnionOpTest.cpp
@@ -179,5 +179,17 @@ namespace tut
         doTest(geoms, "MULTILINESTRING ((0 0, 5 0), (5 0, 10 0, 5 -5, 5 0), (5 0, 5 5))");
     }
 
+    template<>
+    template<>
+    void object::test<7>()
+    {
+        static char const* const geoms[] =
+        {
+            "LINESTRING EMPTY",
+            nullptr
+        };
+        doTest(geoms, "GEOMETRYCOLLECTION EMPTY");
+    }
+
 } // namespace tut