Workaround mono bug, see https://bugzilla.xamarin.com/show_bug.cgi?id=41509 and #219

matthid · matthid · commit 10487ef144ab · 2016-06-04T18:31:30.000+02:00
diff --git a/src/runtime/pyobject.cs b/src/runtime/pyobject.cs
@@ -939,7 +939,7 @@ public override bool TryGetMember(GetMemberBinder binder, out object result)
         {
             if (this.HasAttr(binder.Name))
             {
-                result = this.GetAttr(binder.Name);
+                result = CheckNone(this.GetAttr(binder.Name));
                 return true;
             }
             else
@@ -999,7 +999,7 @@ public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, o
                 try
                 {
                     GetArgs(args, out pyargs, out kwargs);
-                    result = InvokeMethod(binder.Name, pyargs, kwargs);
+                    result = CheckNone(InvokeMethod(binder.Name, pyargs, kwargs));
                 }
                 finally
                 {
@@ -1023,7 +1023,7 @@ public override bool TryInvoke(InvokeBinder binder, object[] args, out object re
                 try
                 {
                     GetArgs(args, out pyargs, out kwargs);
-                    result = Invoke(pyargs, kwargs);
+                    result = CheckNone(Invoke(pyargs, kwargs));
                 }
                 finally
                 {
@@ -1133,10 +1133,26 @@ public override bool TryBinaryOperation(BinaryOperationBinder binder, Object arg
                     result = null;
                     return false;
             }
-            result = new PyObject(res);
+            result = CheckNone(new PyObject(res));
+
             return true;
         }
 
+        // Workaround for https://bugzilla.xamarin.com/show_bug.cgi?id=41509
+        // See https://github.com/pythonnet/pythonnet/pull/219
+        private static object CheckNone(PyObject pyObj)
+        {
+            if (pyObj != null)
+            {
+                if (pyObj.obj == Runtime.PyNone)
+                {
+                    return null;
+                }
+            }
+
+            return pyObj;
+        }
+
         public override bool TryUnaryOperation(UnaryOperationBinder binder, out Object result)
         {
             int r;
@@ -1170,7 +1186,7 @@ public override bool TryUnaryOperation(UnaryOperationBinder binder, out Object r
                     result = null;
                     return false;
             }
-            result = new PyObject(res);
+            result = CheckNone(new PyObject(res));
             return true;
         }
     }

Original file line number	Diff line number	Diff line change
`@@ -939,7 +939,7 @@ public override bool TryGetMember(GetMemberBinder binder, out object result)`
`939`	`939`	`{`
`940`	`940`	`if (this.HasAttr(binder.Name))`
`941`	`941`	`{`
`942`		`- result = this.GetAttr(binder.Name);`
	`942`	`+ result = CheckNone(this.GetAttr(binder.Name));`
`943`	`943`	`return true;`
`944`	`944`	`}`
`945`	`945`	`else`
`@@ -999,7 +999,7 @@ public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, o`
`999`	`999`	`try`
`1000`	`1000`	`{`
`1001`	`1001`	`GetArgs(args, out pyargs, out kwargs);`
`1002`		`- result = InvokeMethod(binder.Name, pyargs, kwargs);`
	`1002`	`+ result = CheckNone(InvokeMethod(binder.Name, pyargs, kwargs));`
`1003`	`1003`	`}`
`1004`	`1004`	`finally`
`1005`	`1005`	`{`
`@@ -1023,7 +1023,7 @@ public override bool TryInvoke(InvokeBinder binder, object[] args, out object re`
`1023`	`1023`	`try`
`1024`	`1024`	`{`
`1025`	`1025`	`GetArgs(args, out pyargs, out kwargs);`
`1026`		`- result = Invoke(pyargs, kwargs);`
	`1026`	`+ result = CheckNone(Invoke(pyargs, kwargs));`
`1027`	`1027`	`}`
`1028`	`1028`	`finally`
`1029`	`1029`	`{`
`@@ -1133,10 +1133,26 @@ public override bool TryBinaryOperation(BinaryOperationBinder binder, Object arg`
`1133`	`1133`	`result = null;`
`1134`	`1134`	`return false;`
`1135`	`1135`	`}`
`1136`		`- result = new PyObject(res);`
	`1136`	`+ result = CheckNone(new PyObject(res));`
	`1137`	`+`
`1137`	`1138`	`return true;`
`1138`	`1139`	`}`
`1139`	`1140`
	`1141`	`+ // Workaround for https://bugzilla.xamarin.com/show_bug.cgi?id=41509`
	`1142`	`+ // See https://github.com/pythonnet/pythonnet/pull/219`
	`1143`	`+ private static object CheckNone(PyObject pyObj)`
	`1144`	`+ {`
	`1145`	`+ if (pyObj != null)`
	`1146`	`+ {`
	`1147`	`+ if (pyObj.obj == Runtime.PyNone)`
	`1148`	`+ {`
	`1149`	`+ return null;`
	`1150`	`+ }`
	`1151`	`+ }`
	`1152`	`+`
	`1153`	`+ return pyObj;`
	`1154`	`+ }`
	`1155`	`+`
`1140`	`1156`	`public override bool TryUnaryOperation(UnaryOperationBinder binder, out Object result)`
`1141`	`1157`	`{`
`1142`	`1158`	`int r;`
`@@ -1170,7 +1186,7 @@ public override bool TryUnaryOperation(UnaryOperationBinder binder, out Object r`
`1170`	`1186`	`result = null;`
`1171`	`1187`	`return false;`
`1172`	`1188`	`}`
`1173`		`- result = new PyObject(res);`
	`1189`	`+ result = CheckNone(new PyObject(res));`
`1174`	`1190`	`return true;`
`1175`	`1191`	`}`
`1176`	`1192`	`}`