From 8d55e394de871134b479ad26cf090f56bd74a45c Mon Sep 17 00:00:00 2001
From: Tracy Wadleigh <tracy.wadleigh@gmail.com>
Date: Thu, 1 Sep 2016 21:10:10 -0700
Subject: [PATCH] Repeatedly divide read buffer size by 8 until success. Fixes
 #11481.

Dividing by 8 leads to success on the second try in the case of the failure of --lisp on Windows 7.
---
 src/support/ios.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/support/ios.c b/src/support/ios.c
index f05c6128d2f6aa..385a24258bfebd 100644
--- a/src/support/ios.c
+++ b/src/support/ios.c
@@ -99,14 +99,20 @@ static int _os_read(long fd, void *buf, size_t n, size_t *nread)
 {
     ssize_t r;
 
+    n = LIMIT_IO_SIZE(n);
     while (1) {
         set_io_wait_begin(1);
-        r = read((int)fd, buf, LIMIT_IO_SIZE(n));
+        r = read((int)fd, buf, n);
         set_io_wait_begin(0);
         if (r > -1) {
             *nread = (size_t)r;
             return 0;
         }
+        // This test is a hack to fix #11481 for Windows 7. Unnecessary for Windows 10.
+        if (errno == ENOMEM && n > 80) {
+            n >>= 3;
+            continue;
+        }
         if (!_enonfatal(errno)) {
             *nread = 0;
             return errno;