From 3e005a8555e8a82784b22dea50fbc7d0bb0ccd26 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Fri, 1 Apr 2016 13:57:15 +0200
Subject: [PATCH] upload: missing rewind call could make libcurl hang

When an upload is done, there are two places where that can be detected
and only one of them would rewind the input stream - which sometimes is
necessary for example when doing NTLM HTTP POSTs and more.

This could then end up libcurl hanging.

Figured-out-by: Isaac Boukris
Reported-by: Anatol Belski

Fixes #741
---
 lib/transfer.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/lib/transfer.c b/lib/transfer.c
index da74ac1fd..9a3e43f70 100644
--- a/lib/transfer.c
+++ b/lib/transfer.c
@@ -816,6 +816,20 @@ static CURLcode readwrite_data(struct SessionHandle *data,
   return CURLE_OK;
 }
 
+static CURLcode done_sending(struct connectdata *conn,
+                             struct SingleRequest *k)
+{
+  k->keepon &= ~KEEP_SEND; /* we're done writing */
+
+  if(conn->bits.rewindaftersend) {
+    CURLcode result = Curl_readrewind(conn);
+    if(result)
+      return result;
+  }
+  return CURLE_OK;
+}
+
+
 /*
  * Send data to upload to the server, when the socket is writable.
  */
@@ -887,14 +901,9 @@ static CURLcode readwrite_upload(struct SessionHandle *data,
         break;
       }
       else if(nread<=0) {
-        /* done */
-        k->keepon &= ~KEEP_SEND; /* we're done writing */
-
-        if(conn->bits.rewindaftersend) {
-          result = Curl_readrewind(conn);
-          if(result)
-            return result;
-        }
+        result = done_sending(conn, k);
+        if(result)
+          return result;
         break;
       }
 
@@ -1004,8 +1013,9 @@ static CURLcode readwrite_upload(struct SessionHandle *data,
       data->req.upload_present = 0; /* no more bytes left */
 
       if(k->upload_done) {
-        /* switch off writing, we're done! */
-        k->keepon &= ~KEEP_SEND; /* we're done writing */
+        result = done_sending(conn, k);
+        if(result)
+          return result;
       }
     }