Implement writing the __cause__ attribute on exceptions.

filmor · filmor · commit e9b22d9f903d · 2016-11-10T19:30:37.000+01:00
diff --git a/src/runtime/clrobject.cs b/src/runtime/clrobject.cs
@@ -32,7 +32,7 @@ internal CLRObject(Object ob, IntPtr tp) : base()
             inst = ob;
 
             // Fix the BaseException args slot if wrapping a CLR exception
-            Exceptions.SetArgs(py);
+            Exceptions.SetArgsAndCause(py);
         }
 
 
diff --git a/src/runtime/exceptions.cs b/src/runtime/exceptions.cs
@@ -144,7 +144,7 @@ internal static void Shutdown()
         /// </summary>
         /// <param name="e">A CLR exception</param>
         /// <param name="ob">The python object wrapping </param>
-        internal static void SetArgs(IntPtr ob)
+        internal static void SetArgsAndCause(IntPtr ob)
         {
             var e = ExceptionClassObject.ToException(ob);
             if (e == null)
@@ -163,6 +163,15 @@ internal static void SetArgs(IntPtr ob)
             }
 
             Marshal.WriteIntPtr(ob, ExceptionOffset.args, args);
+
+#if !(PYTHON25 || PYTHON26 || PYTHON27)
+            if (e.InnerException != null)
+            {
+                IntPtr cause = CLRObject.GetInstHandle(e.InnerException);
+                Runtime.XIncref(cause);
+                Marshal.WriteIntPtr(ob, ExceptionOffset.cause, cause);
+            }
+#endif
         }
 
         /// <summary>

Original file line number	Diff line number	Diff line change
`@@ -32,7 +32,7 @@ internal CLRObject(Object ob, IntPtr tp) : base()`
`32`	`32`	`inst = ob;`
`33`	`33`
`34`	`34`	`// Fix the BaseException args slot if wrapping a CLR exception`
`35`		`- Exceptions.SetArgs(py);`
	`35`	`+ Exceptions.SetArgsAndCause(py);`
`36`	`36`	`}`
`37`	`37`
`38`	`38`