From d2e2caaae6119b5abc2aca3a95e2da7db547eac3 Mon Sep 17 00:00:00 2001
From: Maxime Coste <mawww@kakoune.org>
Date: Fri, 29 Oct 2021 22:34:16 +1100
Subject: [PATCH] Fix incorrect reading logic and EAGAIN handling

This is one of the issues raised by #4410
---
 src/shell_manager.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/shell_manager.cc b/src/shell_manager.cc
index b3605609..bd101633 100644
--- a/src/shell_manager.cc
+++ b/src/shell_manager.cc
@@ -176,9 +176,12 @@ FDWatcher make_reader(int fd, String& contents, OnClose&& on_close)
         char buffer[1024];
         while (fd_readable(fd))
         {
-            size_t size = ::read(fd, buffer, sizeof(buffer));
+            ssize_t size = ::read(fd, buffer, sizeof(buffer));
             if (size <= 0)
             {
+                if (size < 0 and errno == EAGAIN)
+                    continue; // try again
+
                 watcher.disable();
                 on_close();
                 return;