From 0cb5adb49496d971742bd4fdfe98ac3db4dedb94 Mon Sep 17 00:00:00 2001
From: jlp765 <jlp765@gmail.com>
Date: Tue, 1 Nov 2016 13:36:03 +1000
Subject: [PATCH 1/2] Add nill value handling for seq/sets

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

diff --git a/lib/system.nim b/lib/system.nim
index 8648e23b42..7ec74250f5 100644
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -2334,7 +2334,8 @@ proc collectionToString[T: set | seq](x: T, b, e: string): string =
   var firstElement = true
   for value in items(x):
     if not firstElement: result.add(", ")
-    result.add($value)
+    if value.isNil: result.add "nil"
+    else: result.add($value)
     firstElement = false
   result.add(e)
 

From 55b28f86e1fe0b7dc151f93692a987b4a48e98ac Mon Sep 17 00:00:00 2001
From: jlp765 <jlp765@gmail.com>
Date: Tue, 1 Nov 2016 13:41:31 +1000
Subject: [PATCH 2/2] add test: echo a seq with a nil value

---
 tests/stdlib/tnilecho.nim | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 tests/stdlib/tnilecho.nim

diff --git a/tests/stdlib/tnilecho.nim b/tests/stdlib/tnilecho.nim
new file mode 100644
index 0000000000..147b5e4925
--- /dev/null
+++ b/tests/stdlib/tnilecho.nim
@@ -0,0 +1,2 @@
+var x = @["1", nil, "3"]
+doAssert $x == "@[1, nil, 3]"