PyObject.Length raises an exception when object does not have a concept of length

lostmsu · lostmsu · commit 676fbb42cd90 · 2021-02-25T16:06:12.000-08:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -36,6 +36,7 @@ when .NET expects an integer [#1342][i1342]
 -   BREAKING: Methods with `ref` or `out` parameters and void return type return a tuple of only the `ref` and `out` parameters.
 -   BREAKING: to call Python from .NET `Runtime.PythonDLL` property must be set to Python DLL name
 or the DLL must be loaded in advance. This must be done before calling any other Python.NET functions.
+-   BREAKING: `PyObject.Length()` now raises a `PythonException` when object does not support a concept of length.
 -   Sign Runtime DLL with a strong name
 -   Implement loading through `clr_loader` instead of the included `ClrModule`, enables
     support for .NET Core
diff --git a/src/runtime/pyobject.cs b/src/runtime/pyobject.cs
@@ -615,19 +615,15 @@ public virtual void DelItem(int index)
 
 
         /// <summary>
-        /// Length Method
-        /// </summary>
-        /// <remarks>
         /// Returns the length for objects that support the Python sequence
-        /// protocol, or 0 if the object does not support the protocol.
-        /// </remarks>
+        /// protocol.
+        /// </summary>
         public virtual long Length()
         {
-            var s = Runtime.PyObject_Size(obj);
+            var s = Runtime.PyObject_Size(Reference);
             if (s < 0)
             {
-                Runtime.PyErr_Clear();
-                return 0;
+                throw new PythonException();
             }
             return s;
         }
diff --git a/src/runtime/runtime.cs b/src/runtime/runtime.cs
@@ -1115,13 +1115,7 @@ internal static int PyObject_Compare(IntPtr value1, IntPtr value2)
 
         internal static int PyObject_Not(IntPtr pointer) => Delegates.PyObject_Not(pointer);
 
-        internal static long PyObject_Size(IntPtr pointer)
-        {
-            return (long)_PyObject_Size(pointer);
-        }
-
-
-        private static IntPtr _PyObject_Size(IntPtr pointer) => Delegates._PyObject_Size(pointer);
+        internal static nint PyObject_Size(BorrowedReference pointer) => Delegates.PyObject_Size(pointer);
 
 
         internal static nint PyObject_Hash(IntPtr op) => Delegates.PyObject_Hash(op);
@@ -2317,7 +2311,7 @@ static Delegates()
                 PyCallable_Check = (delegate* unmanaged[Cdecl]<IntPtr, int>)GetFunctionByName(nameof(PyCallable_Check), GetUnmanagedDll(_PythonDll));
                 PyObject_IsTrue = (delegate* unmanaged[Cdecl]<BorrowedReference, int>)GetFunctionByName(nameof(PyObject_IsTrue), GetUnmanagedDll(_PythonDll));
                 PyObject_Not = (delegate* unmanaged[Cdecl]<IntPtr, int>)GetFunctionByName(nameof(PyObject_Not), GetUnmanagedDll(_PythonDll));
-                _PyObject_Size = (delegate* unmanaged[Cdecl]<IntPtr, IntPtr>)GetFunctionByName("PyObject_Size", GetUnmanagedDll(_PythonDll));
+                PyObject_Size = (delegate* unmanaged[Cdecl]<BorrowedReference, nint>)GetFunctionByName("PyObject_Size", GetUnmanagedDll(_PythonDll));
                 PyObject_Hash = (delegate* unmanaged[Cdecl]<IntPtr, IntPtr>)GetFunctionByName(nameof(PyObject_Hash), GetUnmanagedDll(_PythonDll));
                 PyObject_Repr = (delegate* unmanaged[Cdecl]<IntPtr, IntPtr>)GetFunctionByName(nameof(PyObject_Repr), GetUnmanagedDll(_PythonDll));
                 PyObject_Str = (delegate* unmanaged[Cdecl]<IntPtr, IntPtr>)GetFunctionByName(nameof(PyObject_Str), GetUnmanagedDll(_PythonDll));
@@ -2589,7 +2583,7 @@ static Delegates()
             internal static delegate* unmanaged[Cdecl]<IntPtr, int> PyCallable_Check { get; }
             internal static delegate* unmanaged[Cdecl]<BorrowedReference, int> PyObject_IsTrue { get; }
             internal static delegate* unmanaged[Cdecl]<IntPtr, int> PyObject_Not { get; }
-            internal static delegate* unmanaged[Cdecl]<IntPtr, IntPtr> _PyObject_Size { get; }
+            internal static delegate* unmanaged[Cdecl]<BorrowedReference, nint> PyObject_Size { get; }
             internal static delegate* unmanaged[Cdecl]<IntPtr, IntPtr> PyObject_Hash { get; }
             internal static delegate* unmanaged[Cdecl]<IntPtr, IntPtr> PyObject_Repr { get; }
             internal static delegate* unmanaged[Cdecl]<IntPtr, IntPtr> PyObject_Str { get; }

Original file line number	Diff line number	Diff line change
`@@ -615,19 +615,15 @@ public virtual void DelItem(int index)`
`615`	`615`
`616`	`616`
`617`	`617`	`/// <summary>`
`618`		`- /// Length Method`
`619`		`- /// </summary>`
`620`		`- /// <remarks>`
`621`	`618`	`/// Returns the length for objects that support the Python sequence`
`622`		`- /// protocol, or 0 if the object does not support the protocol.`
`623`		`- /// </remarks>`
	`619`	`+ /// protocol.`
	`620`	`+ /// </summary>`
`624`	`621`	`public virtual long Length()`
`625`	`622`	`{`
`626`		`- var s = Runtime.PyObject_Size(obj);`
	`623`	`+ var s = Runtime.PyObject_Size(Reference);`
`627`	`624`	`if (s < 0)`
`628`	`625`	`{`
`629`		`- Runtime.PyErr_Clear();`
`630`		`- return 0;`
	`626`	`+ throw new PythonException();`
`631`	`627`	`}`
`632`	`628`	`return s;`
`633`	`629`	`}`