After consuming EOF, only configurations in a RuleStopState are viable

runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java

@@ -947,10 +947,31 @@ public class ParserATNSimulator extends ATNSimulator {
 			}
 		}
 
-		if ( reach.size()==0 ) return null;
+		if (t == IntStream.EOF) {
+			reach = removeNonRuleStopStates(reach);
+		}
+
+		if ( reach.isEmpty() ) return null;
 		return reach;
 	}
 
+	protected ATNConfigSet removeNonRuleStopStates(ATNConfigSet configs) {
+		if (PredictionMode.onlyRuleStopStates(configs)) {
+			return configs;
+		}
+
+		ATNConfigSet result = new ATNConfigSet(configs.fullCtx);
+		for (ATNConfig config : configs) {
+			if (!(config.state instanceof RuleStopState)) {
+				continue;
+			}
+
+			result.add(config, mergeCache);
+		}
+
+		return result;
+	}
+
 	@NotNull
 	public ATNConfigSet computeStartState(@NotNull ATNState p,
 										  @Nullable RuleContext ctx,

tool/test/org/antlr/v4/test/TestFullContextParsing.java

@@ -121,7 +121,7 @@ public class TestFullContextParsing extends BaseTest {
 					 this.stderrDuringParse);
 	}
 
-	@Test(timeout = 5000)
+	@Test
 	public void testSLLSeesEOFInLLGrammar() {
 		String grammar =
 			"grammar T;\n"+
@@ -138,10 +138,9 @@ public class TestFullContextParsing extends BaseTest {
 		String expecting =
 			"Decision 0:\n" +
 			"s0-INT->s1\n" +
-			"s1-ID->s2\n" +
-			"s2-EOF->s3^\n"; // Must point at accept state
+			"s1-ID->s2^\n"; // Must point at accept state
 		assertEquals(expecting, result);
-		assertEquals("line 1:6 reportAttemptingFullContext d=0, input='34abc'\n" +
+		assertEquals("line 1:3 reportAttemptingFullContext d=0, input='34abc'\n" +
 					 "line 1:0 reportContextSensitivity d=0, input='34'\n",
 					 this.stderrDuringParse);
 	}