From fdc05fd0bd5d0a5dc7b8cbafd93e0d0308b85299 Mon Sep 17 00:00:00 2001
From: Oldes <oldes.huhuman@gmail.com>
Date: Wed, 27 Jun 2018 21:36:36 +0200
Subject: [PATCH] FIX: Bitset not allowed in to/thru block

Allow to/thru [bitset|...] in PARSE
For example:
```
>> x: charset "x" y: charset "y" parse "y" [thru [x | y]]
== true
```

Fixes: https://github.com/rebol/rebol-issues/issues/2141

(cherry picked from commit 68a0e0af939e26b52f72e3cd3a64d9c838ff0e98)
---
 src/core/u-parse.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/core/u-parse.c b/src/core/u-parse.c
index a4a017b63a..1728d13a74 100644
--- a/src/core/u-parse.c
+++ b/src/core/u-parse.c
@@ -435,6 +435,11 @@ void Print_Parse_Index(REBCNT type, REBVAL *rules, REBSER *series, REBCNT index)
 						}
 					}
 				}
+				// bitset
+				else if (IS_BITSET(item)) {
+					if (Check_Bit(VAL_SERIES(item), ch1, !HAS_CASE(parse)))
+						goto found1;
+				}
 				else if (ANY_STR(item)) {
 					ch2 = VAL_ANY_CHAR(item);
 					if (!HAS_CASE(parse)) ch2 = UP_CASE(ch2);