[Done] Disallow linearrings with 3 coordinates in GEOS 3.10 (#378)

CHANGELOG.rst

@@ -14,8 +14,9 @@ Version 0.11 (unreleased)
 
 **API Changes**
 
-* ...
-
+* When constructing a linearring through ``pygeos.linearrings`` or a polygon through 
+  ``pygeos.polygons`` now a ``ValueError`` is raised (instead of a ``GEOSException``)
+  if the ring contains less than 4 coordinates including ring closure (#378).
 
 **Added GEOS functions**
 

pygeos/tests/test_creation.py

@@ -127,12 +127,12 @@ def test_linearrings_invalid_shape_scalar():
 )
 def test_linearrings_invalid_shape(shape):
     coords = np.ones(shape)
-    with pytest.raises(pygeos.GEOSException):
+    with pytest.raises(ValueError):
         pygeos.linearrings(coords)
 
     # make sure the first coordinate != second coordinate
     coords[..., 1] += 1
-    with pytest.raises(pygeos.GEOSException):
+    with pytest.raises(ValueError):
         pygeos.linearrings(coords)
 
 
@@ -245,12 +245,12 @@ def test_polygons_not_enough_points_in_shell_scalar():
 )
 def test_polygons_not_enough_points_in_shell(shape):
     coords = np.ones(shape)
-    with pytest.raises(pygeos.GEOSException):
+    with pytest.raises(ValueError):
         pygeos.polygons(coords)
 
     # make sure the first coordinate != second coordinate
     coords[..., 1] += 1
-    with pytest.raises(pygeos.GEOSException):
+    with pytest.raises(ValueError):
         pygeos.polygons(coords)
 
 
@@ -275,12 +275,12 @@ def test_polygons_not_enough_points_in_holes_scalar():
 )
 def test_polygons_not_enough_points_in_holes(shape):
     coords = np.ones(shape)
-    with pytest.raises(pygeos.GEOSException):
+    with pytest.raises(ValueError):
         pygeos.polygons(np.ones((1, 4, 2)), coords)
 
     # make sure the first coordinate != second coordinate
     coords[..., 1] += 1
-    with pytest.raises(pygeos.GEOSException):
+    with pytest.raises(ValueError):
         pygeos.polygons(np.ones((1, 4, 2)), coords)
 
 

src/geos.h

@@ -52,6 +52,7 @@ enum {
   PGERR_GEOMETRY_TYPE,
   PGERR_MULTIPOINT_WITH_POINT_EMPTY,
   PGERR_EMPTY_GEOMETRY,
+  PGERR_LINEARRING_NCOORDS,
   PGWARN_INVALID_WKB,  // raise the GEOS WKB error as a warning instead of exception
   PGWARN_INVALID_WKT   // raise the GEOS WKB error as a warning instead of exception
 };
@@ -87,6 +88,10 @@ enum {
     case PGERR_EMPTY_GEOMETRY:                                                           \
       PyErr_SetString(PyExc_ValueError, "One of the Geometry inputs is empty.");         \
       break;                                                                             \
+    case PGERR_LINEARRING_NCOORDS:                                                       \
+      PyErr_SetString(PyExc_ValueError,                                                  \
+                      "A linearring requires at least 4 coordinates.");                  \
+      break;                                                                             \
     case PGWARN_INVALID_WKB:                                                             \
       PyErr_WarnFormat(PyExc_Warning, 0,                                                 \
                        "Invalid WKB: geometry is returned as None. %s", last_error);     \

src/ufuncs.c

@@ -30,13 +30,13 @@
 
 // Fail if inputs output multiple times on the same place in memory. That would
 // lead to segfaults as the same GEOSGeometry would be 'owned' by multiple PyObjects.
-#define CHECK_NO_INPLACE_OUTPUT(N)                                                \
-  if ((steps[N] == 0) && (dimensions[0] > 1)) {                                   \
-    PyErr_Format(PyExc_NotImplementedError,                                       \
-                 "Zero-strided output detected. Ufunc mode with args[0]=%p, "     \
-                 "args[N]=%p, steps[0]=%ld, steps[N]=%ld, dimensions[0]=%ld.",    \
-                 args[0], args[N], steps[0], steps[N], dimensions[0]);            \
-    return;                                                                       \
+#define CHECK_NO_INPLACE_OUTPUT(N)                                             \
+  if ((steps[N] == 0) && (dimensions[0] > 1)) {                                \
+    PyErr_Format(PyExc_NotImplementedError,                                    \
+                 "Zero-strided output detected. Ufunc mode with args[0]=%p, "  \
+                 "args[N]=%p, steps[0]=%ld, steps[N]=%ld, dimensions[0]=%ld.", \
+                 args[0], args[N], steps[0], steps[N], dimensions[0]);         \
+    return;                                                                    \
   }
 
 #define CHECK_ALLOC(ARR)                                             \
@@ -1947,7 +1947,7 @@ static PyUFuncGenericFunction polygonize_full_funcs[1] = {&polygonize_full_func}
 
 static char shortest_line_dtypes[3] = {NPY_OBJECT, NPY_OBJECT, NPY_OBJECT};
 static void shortest_line_func(char** args, npy_intp* dimensions, npy_intp* steps,
-                                void* data) {
+                               void* data) {
   GEOSGeometry* in1 = NULL;
   GEOSGeometry* in2 = NULL;
   GEOSPreparedGeometry* in1_prepared = NULL;
@@ -2196,6 +2196,12 @@ static void linearrings_func(char** args, npy_intp* dimensions, npy_intp* steps,
         break;
       }
     }
+    /* the minimum number of coordinates in a linearring is 4 */
+    if (n_c1 + ring_closure < 4) {
+      errstate = PGERR_LINEARRING_NCOORDS;
+      destroy_geom_arr(ctx, geom_arr, i - 1);
+      goto finish;
+    }
     /* fill the coordinate sequence */
     coord_seq = GEOSCoordSeq_create_r(ctx, n_c1 + ring_closure, n_c2);
     if (coord_seq == NULL) {
@@ -2932,13 +2938,13 @@ static void to_wkt_func(char** args, npy_intp* dimensions, npy_intp* steps, void
       Py_INCREF(Py_None);
       *out = Py_None;
     } else {
-      // Before GEOS 3.9.0, there was as segfault on e.g. MULTIPOINT (1 1, EMPTY)
-      #if !GEOS_SINCE_3_9_0
+// Before GEOS 3.9.0, there was as segfault on e.g. MULTIPOINT (1 1, EMPTY)
+#if !GEOS_SINCE_3_9_0
       errstate = check_to_wkt_compatible(ctx, in1);
       if (errstate != PGERR_SUCCESS) {
         goto finish;
       }
-      #endif
+#endif
       wkt = GEOSWKTWriter_write_r(ctx, writer, in1);
       if (wkt == NULL) {
         errstate = PGERR_GEOS_EXCEPTION;