From f6537bf4ac8617a732a5f384bd1535ed0b85f303 Mon Sep 17 00:00:00 2001
From: Eric Vergnaud <eric.vergnaud@wanadoo.fr>
Date: Sun, 18 Nov 2018 19:31:47 +0800
Subject: [PATCH] fix #1955 for Chsarp

---
 .../Antlr4.Runtime/Atn/ParserATNSimulator.cs  | 35 ++++++++++---------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/ParserATNSimulator.cs b/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/ParserATNSimulator.cs
index ccc1b502d..a7d914a71 100644
--- a/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/ParserATNSimulator.cs
+++ b/runtime/CSharp/runtime/CSharp/Antlr4.Runtime/Atn/ParserATNSimulator.cs
@@ -1622,12 +1622,6 @@ namespace Antlr4.Runtime.Atn
 											   depth == 0, fullCtx, treatEofAsEpsilon);
 				if (c != null)
 				{
-					if (!t.IsEpsilon && !closureBusy.Add(c))
-					{
-						// avoid infinite recursion for EOF* and EOF+
-						continue;
-					}
-
 					int newDepth = depth;
 					if (config.state is RuleStopState)
 					{
@@ -1637,12 +1631,6 @@ namespace Antlr4.Runtime.Atn
 						// come in handy and we avoid evaluating context dependent
 						// preds if this is > 0.
 
-						if (!closureBusy.Add(c))
-						{
-							// avoid infinite recursion for right-recursive rules
-							continue;
-						}
-
 						if (thisDfa != null && thisDfa.IsPrecedenceDfa)
 						{
 							int outermostPrecedenceReturn = ((EpsilonTransition)t).OutermostPrecedenceReturn;
@@ -1653,17 +1641,32 @@ namespace Antlr4.Runtime.Atn
 						}
 
 						c.reachesIntoOuterContext++;
+						if (!closureBusy.Add(c))
+						{
+							// avoid infinite recursion for right-recursive rules
+							continue;
+						}
+
 						configs.dipsIntoOuterContext = true; // TODO: can remove? only care when we add to set per middle of this method
 						newDepth--;
 						if (debug)
 							ConsoleWriteLine("dips into outer ctx: " + c);
 					}
-					else if (t is RuleTransition)
+					else
 					{
-						// latch when newDepth goes negative - once we step out of the entry context we can't return
-						if (newDepth >= 0)
+
+						if (!t.IsEpsilon && !closureBusy.Add(c))
 						{
-							newDepth++;
+							// avoid infinite recursion for EOF* and EOF+
+							continue;
+						}
+						if (t is RuleTransition)
+						{
+							// latch when newDepth goes negative - once we step out of the entry context we can't return
+							if (newDepth >= 0)
+							{
+								newDepth++;
+							}
 						}
 					}