If an interrupt causing overflow would occur between reading
_buffer_overflow and clearing it, this overflow condition would be
immediately cleared and never be returned by overflow().
By only clearing the overflow flag if an overflow actually occurred,
this problem goes away (worst case overflow() returns false even though
an overflow _just_ occurred, but then the next call to overflow() will
return true).
This prevents interrupts from triggering when the SoftwareSerial
instance is not even listening.
Additionally, this removes the need to disable interrupts in
SoftwareSerial::listen, since no interrupts are active while it touches
the variables.
The current check is still always false when the old check was, but
additionally it will not disable the interrupts when they were never
enabled (which shouldn't matter much, but this is more consistent).
In this case, SoftwareSerial::begin will not have enabled the
interrupts, so better not allow the SoftwareSerial instance to enter the
listening state either.
Before enabling interupts, begin would see if the given receive pin
actually has an associated PCINT register. If not, the interrupts would
not be enabled.
Now, the same check is done, but when no register is available, the rx
parameters are not loaded at all (which in turn prevents the interrupt
from being enabled). This allows all code to use the same "is rx
enabled" (which will be added next).
* master: (148 commits)
Update revision log
Cherry picked fix from 87865ac19d
Updated revision log
Added dependencies for AStylej.dll
Updated translations
Update revision log
Temporary fix for pulseIn() regression.
Added README.adoc for the library manager project
Fixed some libraries metadata.
Temporary disabled DefaultTargetTest under certain conditions
Updated translation from transifex
Updated some translation strings
Fixed test
sam: Fixed initialization of UART/USART mode register
update revision log
Fixed NPE when import menu are empty
Fixed NPE when currently selected platform is no more installed.
Optimized FileUtils.recursiveDelete(File) function
Fixed a bunch of simple warnings in java code
Removed unused classes Commander.java and Webserver.java
...
