- adds defensive programing to avoid dependency on null entity type

Signed-off-by: Vincent Biret <[email protected]>

Author: baywet

src/Microsoft.OpenApi.OData.Reader/Edm/EdmModelExtensions.cs

@@ -157,7 +157,7 @@ public static bool IsAssignableFrom(this IEdmEntityType baseType, IEdmEntityType
             Utils.CheckArgumentNull(baseType, nameof(baseType));
             Utils.CheckArgumentNull(subtype, nameof(subtype));
 
-            if (baseType.TypeKind != subtype.TypeKind)
+            if (baseType == null || subtype == null || baseType.TypeKind != subtype.TypeKind)
             {
                 return false;
             }

src/Microsoft.OpenApi.OData.Reader/Edm/ODataPathProvider.cs

@@ -135,14 +135,15 @@ private void AppendPath(ODataPath path)
                 case ODataPathKind.EntitySet:
                 case ODataPathKind.Singleton:
                 case ODataPathKind.MediaEntity:
-                    ODataNavigationSourceSegment navigationSourceSegment = (ODataNavigationSourceSegment)path.FirstSegment;
-                    if (!_allNavigationSourcePaths.TryGetValue(navigationSourceSegment.EntityType, out IList<ODataPath> nsList))
+                    if (path.FirstSegment is ODataNavigationSourceSegment navigationSourceSegment)
                     {
-                        nsList = new List<ODataPath>();
-                        _allNavigationSourcePaths[navigationSourceSegment.EntityType] = nsList;
+                        if(!_allNavigationSourcePaths.TryGetValue(navigationSourceSegment.EntityType, out IList<ODataPath> nsList))
+                        {
+                            nsList = new List<ODataPath>();
+                            _allNavigationSourcePaths[navigationSourceSegment.EntityType] = nsList;
+                        }
+                        nsList.Add(path);
                     }
-
-                    nsList.Add(path);
                     break;
 
                 case ODataPathKind.NavigationProperty: