ParameterInfo.Name needs to be checked for null before usage (#1375)

filmor · filmor · commit 4cb551e3f1f8 · 2021-02-04T21:59:20.000+01:00
This occured in trying to use F# code from Python. As the `.Name` property returns `null`, `ContainsKey` fails. Related documentation: https://docs.microsoft.com/en-us/dotnet/api/system.reflection.parameterinfo.name
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -9,7 +9,8 @@ This document follows the conventions laid out in [Keep a CHANGELOG][].
 ## Unreleased
 
 ### Fixed
--    Fix `object[]` parameters taking precedence when should not in overload resolution
+-   Fix `object[]` parameters taking precedence when should not in overload resolution
+-   Empty parameter names (as can be generated from F#) do not cause crashes
 
 ## [2.5.1][] - 2020-06-18
 
diff --git a/src/runtime/methodbinder.cs b/src/runtime/methodbinder.cs
@@ -427,7 +427,7 @@ static object[] TryConvertArguments(ParameterInfo[] pi, bool paramsArray,
             for (int paramIndex = 0; paramIndex < pi.Length; paramIndex++)
             {
                 var parameter = pi[paramIndex];
-                bool hasNamedParam = kwargDict.ContainsKey(parameter.Name);
+                bool hasNamedParam = parameter.Name != null ? kwargDict.ContainsKey(parameter.Name) : false;
                 bool isNewReference = false;
 
                 if (paramIndex >= pyArgCount && !(hasNamedParam || (paramsArray && paramIndex == arrayStart)))

Original file line number	Diff line number	Diff line change
`@@ -427,7 +427,7 @@ static object[] TryConvertArguments(ParameterInfo[] pi, bool paramsArray,`
`427`	`427`	`for (int paramIndex = 0; paramIndex < pi.Length; paramIndex++)`
`428`	`428`	`{`
`429`	`429`	`var parameter = pi[paramIndex];`
`430`		`- bool hasNamedParam = kwargDict.ContainsKey(parameter.Name);`
	`430`	`+ bool hasNamedParam = parameter.Name != null ? kwargDict.ContainsKey(parameter.Name) : false;`
`431`	`431`	`bool isNewReference = false;`
`432`	`432`
`433`	`433`	`if (paramIndex >= pyArgCount && !(hasNamedParam \|\| (paramsArray && paramIndex == arrayStart)))`