[reflection] Throw TLE for Type.GetType("", true) (Fixes #59664)

In the C parser check for empty at the outset.
In the managed parser, copy an empty string component to the built-up TypeSpec
and handle it in the Type.GetType (..., asmResolver, typeResolver) implementation

3 files changed, 13 insertions, 19 deletions

diff --git a/mcs/class/corlib/ReferenceSources/Type.cs b/mcs/class/corlib/ReferenceSources/Type.cs
index a77d734c366..664782b1706 100644
--- a/mcs/class/corlib/ReferenceSources/Type.cs
+++ b/mcs/class/corlib/ReferenceSources/Type.cs
@@ -43,22 +43,12 @@ namespace System
 
 		public static Type GetType(string typeName)
 		{
-			if (typeName == null)
-				throw new ArgumentNullException ("TypeName");
-
-			return internal_from_name (typeName, false, false);
+			return GetType (typeName, false, false);
 		}
 
 		public static Type GetType(string typeName, bool throwOnError)
 		{
-			if (typeName == null)
-				throw new ArgumentNullException ("TypeName");
-
-			Type type = internal_from_name (typeName, throwOnError, false);
-			if (throwOnError && type == null)
-				throw new TypeLoadException ("Error loading '" + typeName + "'");
-
-			return type;
+			return GetType (typeName, throwOnError, false);
 		}
 
 		public static Type GetType(string typeName, bool throwOnError, bool ignoreCase)
@@ -66,6 +56,11 @@ namespace System
 			if (typeName == null)
 				throw new ArgumentNullException ("TypeName");
 
+			if (typeName == String.Empty)
+				if (throwOnError)
+					throw new TypeLoadException ("A null or zero length string does not represent a valid Type.");
+				else
+					return null;
 			Type t = internal_from_name (typeName, throwOnError, ignoreCase);
 			if (throwOnError && t == null)
 				throw new TypeLoadException ("Error loading '" + typeName + "'");
@@ -82,6 +77,8 @@ namespace System
 		{
 			if (typeName == null)
 				throw new ArgumentNullException ("typeName");
+			if (typeName == String.Empty && throwIfNotFound)
+				throw new TypeLoadException ("A null or zero length string does not represent a valid Type");
 			int idx = typeName.IndexOf (',');
 			if (idx < 0 || idx == 0 || idx == typeName.Length - 1)
 				throw new ArgumentException ("Assembly qualifed type name is required", "typeName");
diff --git a/mcs/class/corlib/System/TypeSpec.cs b/mcs/class/corlib/System/TypeSpec.cs
index f233bec088e..4436a77810f 100644
--- a/mcs/class/corlib/System/TypeSpec.cs
+++ b/mcs/class/corlib/System/TypeSpec.cs
@@ -455,7 +455,9 @@ namespace System {
 			}
 
 			if (name_start < pos)
-				data.AddName (name.Substring (name_start, pos - name_start));		
+				data.AddName (name.Substring (name_start, pos - name_start));
+			else if (name_start == pos)
+				data.AddName (String.Empty);
 
 			if (in_modifiers) {
 				for (; pos < name.Length; ++pos) {
diff --git a/mono/metadata/reflection.c b/mono/metadata/reflection.c
index 3401a59eda0..e69c5d42c28 100644
--- a/mono/metadata/reflection.c
+++ b/mono/metadata/reflection.c
@@ -1546,12 +1546,7 @@ _mono_reflection_parse_type (char *name, char **endptr, gboolean is_recursed,
 
 	start = p = w = name;
 
-	//FIXME could we just zero the whole struct? memset (&info, 0, sizeof (MonoTypeNameParse))
-	memset (&info->assembly, 0, sizeof (MonoAssemblyName));
-	info->name = info->name_space = NULL;
-	info->nested = NULL;
-	info->modifiers = NULL;
-	info->type_arguments = NULL;
+	memset (info, 0, sizeof (MonoTypeNameParse));
 
 	/* last_point separates the namespace from the name */
 	last_point = NULL;