From 83c657c010a3f6ce647e305f7a77e73c65b8a001 Mon Sep 17 00:00:00 2001
From: Johannes Altmanninger <aclopte@gmail.com>
Date: Sun, 10 May 2020 22:29:14 +0200
Subject: [PATCH] Fix IO error handling in non-interactive reader

This used to use fread(2) which returns size_t, but read(2) returns
an ssize_t of -1 on error.

Fixes #6990
---
 src/reader.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/reader.cpp b/src/reader.cpp
index 6cc6fabe9..48f89d7a2 100644
--- a/src/reader.cpp
+++ b/src/reader.cpp
@@ -3762,13 +3762,14 @@ static int read_ni(parser_t &parser, int fd, const io_chain_t &io) {
     std::string fd_contents;
     for (;;) {
         char buff[4096];
-        size_t amt = read(fd, buff, sizeof buff);
+        ssize_t amt = read(fd, buff, sizeof buff);
         if (amt > 0) {
             fd_contents.append(buff, amt);
         } else if (amt == 0) {
             // EOF.
             break;
         } else {
+            assert(amt == -1);
             int err = errno;
             if (err == EINTR) {
                 continue;