From 3f1a85b7f03a4998f09a4fe6e8bf13672742fcb9 Mon Sep 17 00:00:00 2001
From: Araq <rumpf_a@web.de>
Date: Wed, 18 Mar 2020 10:47:46 +0100
Subject: [PATCH] fixes hash(HashSet) which was wrong as it didn't respect
 tombstones; refs #13649

---
 lib/pure/collections/sets.nim | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/pure/collections/sets.nim b/lib/pure/collections/sets.nim
index 9f800e6d1f..caa25dbb31 100644
--- a/lib/pure/collections/sets.nim
+++ b/lib/pure/collections/sets.nim
@@ -574,7 +574,8 @@ proc map*[A, B](data: HashSet[A], op: proc (x: A): B {.closure.}): HashSet[B] =
 proc hash*[A](s: HashSet[A]): Hash =
   ## Hashing of HashSet.
   for h in 0 .. high(s.data):
-    result = result xor s.data[h].hcode
+    if isFilledAndValid(s.data[h].hcode):
+      result = result xor s.data[h].hcode
   result = !$result
 
 proc `$`*[A](s: HashSet[A]): string =