From 2d0cb18b9f092fad54abefed475218ae92fc846c Mon Sep 17 00:00:00 2001
From: Daehee <hello@daehee.com>
Date: Fri, 22 Jan 2021 07:04:52 -0700
Subject: [PATCH] Fix SIGSEGV in httpclient response body (#16766)

* initialize httpclient response bodyStream; prevent SIGSEGV when getBody is false

* Update lib/pure/httpclient.nim

* Update lib/pure/httpclient.nim

Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
---
 lib/pure/httpclient.nim      | 10 ++++++----
 tests/stdlib/thttpclient.nim |  6 ++++++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/lib/pure/httpclient.nim b/lib/pure/httpclient.nim
index bcd10803ee..0ca3ca97bf 100644
--- a/lib/pure/httpclient.nim
+++ b/lib/pure/httpclient.nim
@@ -832,14 +832,16 @@ proc parseResponse(client: HttpClient | AsyncHttpClient,
   if not fullyRead:
     httpError("Connection was closed before full request has been made")
 
+  when client is HttpClient:
+    result.bodyStream = newStringStream()
+  else:
+    result.bodyStream = newFutureStream[string]("parseResponse")
+
   if getBody and result.code != Http204:
+    client.bodyStream = result.bodyStream
     when client is HttpClient:
-      client.bodyStream = newStringStream()
-      result.bodyStream = client.bodyStream
       parseBody(client, result.headers, result.version)
     else:
-      client.bodyStream = newFutureStream[string]("parseResponse")
-      result.bodyStream = client.bodyStream
       assert(client.parseBodyFut.isNil or client.parseBodyFut.finished)
       # do not wait here for the body request to complete
       client.parseBodyFut = parseBody(client, result.headers, result.version)
diff --git a/tests/stdlib/thttpclient.nim b/tests/stdlib/thttpclient.nim
index 0cef10e6dc..e81590d951 100644
--- a/tests/stdlib/thttpclient.nim
+++ b/tests/stdlib/thttpclient.nim
@@ -148,6 +148,12 @@ proc syncTest() =
 
   client.close()
 
+  # SIGSEGV on HEAD body read: issue #16743
+  block:
+    let client = newHttpClient()
+    let resp = client.head("http://httpbin.org/head")
+    doAssert(resp.body == "")
+
   when false:
     # Disabled for now because it causes troubles with AppVeyor
     # Timeout test.