From e0937a6322c18a27a3638b1937e6f395ae14ec9a Mon Sep 17 00:00:00 2001
From: Sam Harwell <sam@tunnelvisionlabs.com>
Date: Sat, 24 May 2014 13:14:08 -0500
Subject: [PATCH] Add regression test for #561 (token named ATN breaks
 reference to ATN.INVALID_ALT_NUMBER)

---
 .../org/antlr/v4/test/TestParserExec.java     | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tool/test/org/antlr/v4/test/TestParserExec.java b/tool/test/org/antlr/v4/test/TestParserExec.java
index 53b5db1c6..c61f7c09e 100644
--- a/tool/test/org/antlr/v4/test/TestParserExec.java
+++ b/tool/test/org/antlr/v4/test/TestParserExec.java
@@ -441,4 +441,25 @@ public class TestParserExec extends BaseTest {
 		assertEquals("", found);
 		assertNull(stderrDuringParse);
 	}
+
+	/**
+	 * This is a regression test for antlr/antlr4#561 "Issue with parser
+	 * generation in 4.2.2"
+	 * https://github.com/antlr/antlr4/issues/561
+	 */
+	@Test public void testReferenceToATN() throws Exception {
+		String grammar =
+			"grammar T;\n" +
+			"a : (ID|ATN)* ATN? {System.out.println($text);} ;\n" +
+			"ID : 'a'..'z'+ ;\n" +
+			"ATN : '0'..'9'+;\n" +
+			"WS : (' '|'\\n') -> skip ;\n";
+
+		String found = execParser("T.g4", grammar, "TParser", "TLexer", "a",
+								  "", false);
+		assertEquals("\n", found);
+		found = execParser("T.g4", grammar, "TParser", "TLexer", "a",
+								  "a 34 c", false);
+		assertEquals("a34c\n", found);
+	}
 }