From bbf5df7532abf9d418e0f804ec5cca0be6dcaefb Mon Sep 17 00:00:00 2001
From: Josh Allmann <joshua.allmann@gmail.com>
Date: Sat, 21 Mar 2015 19:22:46 -0700
Subject: [PATCH] Lwt_unix_io: Split large reads.

With the Lwt backend, reads hang if trying to fetch more than
Sys.max_string_length due to a byte allocation failure in
Lwt_io.read. Problematic for large uploads, etc.

Upper layer callers (eg, Transfer_io) seem to handle recombining
these split reads without any issues.
---
 lwt/cohttp_lwt_unix_io.ml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lwt/cohttp_lwt_unix_io.ml b/lwt/cohttp_lwt_unix_io.ml
index 4a57b07b86..711ec40624 100644
--- a/lwt/cohttp_lwt_unix_io.ml
+++ b/lwt/cohttp_lwt_unix_io.ml
@@ -37,6 +37,7 @@ let read_line ic =
     Lwt_io.read_line_opt ic
 
 let read ic count =
+ let count = min count Sys.max_string_length in
  if !CD.debug_active then
    (lwt buf =
        try_lwt Lwt_io.read ~count ic