Fix segfault in get_global_index1F

Co-authored-by: Zohar Malamant <zom@equinor.com>

lib/resdata/rd_grid.cpp

@@ -4752,6 +4752,9 @@ int rd_grid_get_global_index1A(const rd_grid_type *rd_grid, int active_index) {
 
 int rd_grid_get_global_index1F(const rd_grid_type *rd_grid,
                                int active_fracture_index) {
+    if (rd_grid->inv_fracture_index_map == NULL ||
+        active_fracture_index >= rd_grid->total_active_fracture)
+        return -1;
     return rd_grid->inv_fracture_index_map[active_fracture_index];
 }
 

python/resdata/grid/rd_grid.py

@@ -581,8 +581,13 @@ def get_active_fracture_index(self, ijk=None, global_index=None):
     def get_global_index1F(self, active_fracture_index):
         """
         Will return the global index corresponding to active fracture index.
+
+        Returns None if there is no active_fracture with that index
         """
-        return self._get_global_index1F(active_fracture_index)
+        result = self._get_global_index1F(active_fracture_index)
+        if result == -1:
+            return None
+        return result
 
     def cell_invalid(self, ijk=None, global_index=None, active_index=None):
         """

python/tests/rd_tests/test_grid.py

@@ -222,6 +222,7 @@ def test_posXYEdge(self):
 
     def test_dims(self):
         grid = GridGen.createRectangular((10, 20, 30), (1, 1, 1))
+        self.assertEqual(grid.get_global_index1F(0), None)
         self.assertEqual(grid.getNX(), 10)
         self.assertEqual(grid.getNY(), 20)
         self.assertEqual(grid.getNZ(), 30)