From 8f2eca5ae1e35930a8c84891ed429f8ef00a7ed7 Mon Sep 17 00:00:00 2001
From: Terence Parr <parrt@antlr.org>
Date: Fri, 22 May 2015 12:03:28 -0700
Subject: [PATCH 1/2] added playground stuff

---
 tool/playground/Main.java | 48 +++++++++++++++++++++++++++++++++++++++
 tool/playground/T.g4      |  8 +++++++
 tool/tool.iml             |  1 +
 3 files changed, 57 insertions(+)
 create mode 100644 tool/playground/Main.java
 create mode 100644 tool/playground/T.g4

diff --git a/tool/playground/Main.java b/tool/playground/Main.java
new file mode 100644
index 000000000..5a441efcb
--- /dev/null
+++ b/tool/playground/Main.java
@@ -0,0 +1,48 @@
+import org.antlr.v4.runtime.ANTLRInputStream;
+import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.ParserRuleContext;
+
+public class Main
+{
+    public static void main(String[] args)
+    {
+        TParser parser = new TParser(new CommonTokenStream(new TLexer(new ANTLRInputStream("b"))));
+        parser.addParseListener(new MyTBaseListener());
+
+		parser.a();
+
+		System.out.println("######################");
+		parser = new TParser(new CommonTokenStream(new TLexer(new ANTLRInputStream("x"))));
+		parser.addParseListener(new MyTBaseListener());
+		parser.b();
+    }
+
+	private static class MyTBaseListener extends TBaseListener {
+		@Override
+		public void enterAlt1(TParser.Alt1Context ctx)
+		{
+			System.out.println("entering alt1");
+		}
+
+		@Override
+		public void exitAlt1(TParser.Alt1Context ctx)
+		{
+			System.out.println("exiting alt1");
+		}
+
+		@Override
+		public void enterB(TParser.BContext ctx) {
+			System.out.println("enter b");
+		}
+
+		@Override
+		public void exitB(TParser.BContext ctx) {
+			System.out.println("exiting b");
+		}
+
+		@Override
+		public void enterEveryRule(ParserRuleContext ctx) {
+			System.out.println("enterEveryRule");
+		}
+	}
+}
diff --git a/tool/playground/T.g4 b/tool/playground/T.g4
new file mode 100644
index 000000000..33b79b8f9
--- /dev/null
+++ b/tool/playground/T.g4
@@ -0,0 +1,8 @@
+grammar T;
+
+a
+    : 'b'   #alt1
+    | 'c'   #alt2
+    ;
+
+b : 'x' | 'y' {} ;
diff --git a/tool/tool.iml b/tool/tool.iml
index 44b1c5917..252bf4581 100644
--- a/tool/tool.iml
+++ b/tool/tool.iml
@@ -16,6 +16,7 @@
       <sourceFolder url="file://$MODULE_DIR$/resources" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/../gen3" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/../antlr4-maven-plugin/resources" type="java-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/playground" isTestSource="false" />
       <excludeFolder url="file://$MODULE_DIR$/../.idea" />
       <excludeFolder url="file://$MODULE_DIR$/../antlr4-maven-plugin" />
       <excludeFolder url="file://$MODULE_DIR$/../build" />

From a8b67147c236c4a032b957fc3eb4ace279ff0350 Mon Sep 17 00:00:00 2001
From: Terence Parr <parrt@antlr.org>
Date: Fri, 22 May 2015 12:58:28 -0700
Subject: [PATCH 2/2] Fixes #879. only gen parse listener enterRule events in
 enterOuterAlt, not enterRule.

---
 runtime/Java/src/org/antlr/v4/runtime/Parser.java | 1 -
 1 file changed, 1 deletion(-)

diff --git a/runtime/Java/src/org/antlr/v4/runtime/Parser.java b/runtime/Java/src/org/antlr/v4/runtime/Parser.java
index 2bc1eb49d..a2947eda6 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/Parser.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/Parser.java
@@ -626,7 +626,6 @@ public abstract class Parser extends Recognizer<Token, ParserATNSimulator> {
 		_ctx = localctx;
 		_ctx.start = _input.LT(1);
 		if (_buildParseTrees) addContextToParseTree();
-        if ( _parseListeners != null) triggerEnterRuleEvent();
 	}
 
     public void exitRule() {