From 298de834a29e7b5dfa1d5109fedba1c4aacddd3d Mon Sep 17 00:00:00 2001
From: M Hightower <27247790+mhightower83@users.noreply.github.com>
Date: Fri, 28 Jun 2019 14:24:16 -0700
Subject: [PATCH] Do not call yield() from timedRead() or timedPeek() when
 _timeout is set to 0.

---
 cores/esp8266/Stream.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/cores/esp8266/Stream.cpp b/cores/esp8266/Stream.cpp
index a29388b2bf..3d7f5bc23f 100644
--- a/cores/esp8266/Stream.cpp
+++ b/cores/esp8266/Stream.cpp
@@ -33,6 +33,8 @@ int Stream::timedRead() {
         c = read();
         if(c >= 0)
             return c;
+        if(_timeout == 0)
+            return -1;
         yield();
     } while(millis() - _startMillis < _timeout);
     return -1;     // -1 indicates timeout
@@ -46,6 +48,8 @@ int Stream::timedPeek() {
         c = peek();
         if(c >= 0)
             return c;
+        if(_timeout == 0)
+            return -1;
         yield();
     } while(millis() - _startMillis < _timeout);
     return -1;     // -1 indicates timeout
@@ -254,4 +258,3 @@ String Stream::readStringUntil(char terminator) {
     }
     return ret;
 }
-