From ef196340659af5a22c9149e7dd81aebddd5ec660 Mon Sep 17 00:00:00 2001
From: Dominik Picheta <dominikpicheta@googlemail.com>
Date: Thu, 18 Jan 2018 13:08:35 +0000
Subject: [PATCH] Workaround 'defer' issue in httpclient.downloadFile. Refs
 #3877. (#7101)

---
 lib/pure/httpclient.nim | 43 +++++++++++++++++++++++++++++------------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/lib/pure/httpclient.nim b/lib/pure/httpclient.nim
index aefcff37a7..4c40a81fe1 100644
--- a/lib/pure/httpclient.nim
+++ b/lib/pure/httpclient.nim
@@ -1263,21 +1263,30 @@ proc postContent*(client: HttpClient | AsyncHttpClient, url: string,
   else:
     return await resp.bodyStream.readAll()
 
-proc downloadFile*(client: HttpClient | AsyncHttpClient,
-                   url: string, filename: string): Future[void] {.multisync.} =
+proc downloadFile*(client: HttpClient, url: string, filename: string) =
   ## Downloads ``url`` and saves it to ``filename``.
   client.getBody = false
   defer:
     client.getBody = true
-  let resp = await client.get(url)
+  let resp = client.get(url)
+
+  client.bodyStream = newFileStream(filename, fmWrite)
+  if client.bodyStream.isNil:
+    fileError("Unable to open file")
+  parseBody(client, resp.headers, resp.version)
+  client.bodyStream.close()
+
+  if resp.code.is4xx or resp.code.is5xx:
+    raise newException(HttpRequestError, resp.status)
+
+proc downloadFile*(client: AsyncHttpClient, url: string,
+                   filename: string): Future[void] =
+  proc downloadFileEx(client: AsyncHttpClient,
+                      url, filename: string): Future[void] {.async.} =
+    ## Downloads ``url`` and saves it to ``filename``.
+    client.getBody = false
+    let resp = await client.get(url)
 
-  when client is HttpClient:
-    client.bodyStream = newFileStream(filename, fmWrite)
-    if client.bodyStream.isNil:
-      fileError("Unable to open file")
-    parseBody(client, resp.headers, resp.version)
-    client.bodyStream.close()
-  else:
     client.bodyStream = newFutureStream[string]("downloadFile")
     var file = openAsync(filename, fmWrite)
     # Let `parseBody` write response data into client.bodyStream in the
@@ -1288,5 +1297,15 @@ proc downloadFile*(client: HttpClient | AsyncHttpClient,
     await file.writeFromStream(client.bodyStream)
     file.close()
 
-  if resp.code.is4xx or resp.code.is5xx:
-    raise newException(HttpRequestError, resp.status)
+    if resp.code.is4xx or resp.code.is5xx:
+      raise newException(HttpRequestError, resp.status)
+
+  result = newFuture[void]("downloadFile")
+  try:
+    result = downloadFileEx(client, url, filename)
+  except Exception as exc:
+    result.fail(exc)
+  finally:
+    result.addCallback(
+      proc () = client.getBody = true
+    )
\ No newline at end of file