From c7c8c0700f9f72663102167f739219faa04d7c56 Mon Sep 17 00:00:00 2001
From: Sebastian Hartte <sebastian@hartte.de>
Date: Wed, 20 Mar 2019 17:23:11 +0100
Subject: [PATCH] Fix parsing of generic type declarations in C# source files.

(cherry picked from commit 34366bc27fddd69539562c12579b3207b23676fe)
---
 modules/mono/editor/script_class_parser.cpp | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/modules/mono/editor/script_class_parser.cpp b/modules/mono/editor/script_class_parser.cpp
index 6b2ec5cc20a..dfb652a7aa6 100644
--- a/modules/mono/editor/script_class_parser.cpp
+++ b/modules/mono/editor/script_class_parser.cpp
@@ -266,6 +266,20 @@ Error ScriptClassParser::_skip_generic_type_params() {
 
 		if (tk == TK_IDENTIFIER) {
 			tk = get_token();
+			// Type specifications can end with "?" to denote nullable types, such as IList<int?>
+			if (tk == TK_SYMBOL) {
+				tk = get_token();
+				if (value.operator String() != "?") {
+					error_str = "Expected " + get_token_name(TK_IDENTIFIER) + ", found unexpected symbol '" + value + "'";
+					error = true;
+					return ERR_PARSE_ERROR;
+				}
+				if (tk != TK_OP_GREATER && tk != TK_COMMA) {
+					error_str = "Nullable type symbol '?' is only allowed after an identifier, but found " + get_token_name(tk) + " next.";
+					error = true;
+					return ERR_PARSE_ERROR;
+				}
+			}
 
 			if (tk == TK_PERIOD) {
 				while (true) {