Revert removal of PolledTimeout::alwaysExpired

Author: dok-net

cores/esp8266/PolledTimeout.h

@@ -146,6 +146,7 @@ class timeoutTemplate
   using timeType = typename TimePolicyT::timeType;
   static_assert(std::is_unsigned<timeType>::value == true, "timeType must be unsigned");
 
+  static constexpr timeType alwaysExpired   = 0;
   static constexpr timeType neverExpires    = std::numeric_limits<timeType>::max();
   static constexpr timeType rangeCompensate = TimePolicyT::rangeCompensate; //debug
 
@@ -176,7 +177,7 @@ class timeoutTemplate
 
   bool canWait () const
   {
-    return _timeout != 0;
+    return _timeout != alwaysExpired;
   }
 
   // Resets, will trigger after this new timeout.
@@ -214,7 +215,7 @@ class timeoutTemplate
 
   void resetToNeverExpires ()
   {
-    _timeout = 1; // because canWait() has precedence
+    _timeout = alwaysExpired + 1; // because canWait() has precedence
     _neverExpires = true;
   }
 

cores/esp8266/Stream.h

@@ -171,7 +171,7 @@ class Stream: public Print {
 
         // transfers already buffered / immediately available data (no timeout)
         // returns number of transferred bytes
-        [[deprecated]] size_t sendAvailable (Print* to) { return sendGeneric(to, -1, -1, 0); }
+        [[deprecated]] size_t sendAvailable (Print* to) { return sendGeneric(to, -1, -1, oneShotMs::alwaysExpired); }
         [[deprecated]] size_t sendAvailable (Print& to) { return sendAvailable(&to); }
 
         // transfers data until timeout