From e3b19cbe52e0578de315d259fbb066bfe991a60f Mon Sep 17 00:00:00 2001 From: Aditya Siram Date: Sat, 25 Sep 2021 07:17:41 -0500 Subject: [PATCH] fixes #18878 (#18883) --- lib/core/typeinfo.nim | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/lib/core/typeinfo.nim b/lib/core/typeinfo.nim index d66dc18980..18d2091b9f 100644 --- a/lib/core/typeinfo.nim +++ b/lib/core/typeinfo.nim @@ -216,7 +216,8 @@ proc extendSeq*(x: Any) = when defined(gcDestructors): var s = cast[ptr NimSeqV2Reimpl](x.value) let elem = x.rawType.base - s.p = cast[ptr NimSeqPayloadReimpl](prepareSeqAdd(s.len, s.p, 1, elem.size, elem.align)) + if s.p == nil or s.p.cap < s.len+1: + s.p = cast[ptr NimSeqPayloadReimpl](prepareSeqAdd(s.len, s.p, 1, elem.size, elem.align)) inc s.len else: var y = cast[ptr PGenSeq](x.value)[]