Merge pull request #494 from kalvdans/dont-catch-our-own-exception

posix: Don't catch the SerialException we just raised

1 files changed, 12 insertions, 10 deletions

diff --git a/serial/serialposix.py b/serial/serialposix.py
index f31b99d..0e97d58 100644
--- a/serial/serialposix.py
+++ b/serial/serialposix.py
@@ -548,16 +548,6 @@ class Serial(SerialBase, PlatformSpecific):
                 if not ready:
                     break   # timeout
                 buf = os.read(self.fd, size - len(read))
-                # read should always return some data as select reported it was
-                # ready to read when we get to this point.
-                if not buf:
-                    # Disconnected devices, at least on Linux, show the
-                    # behavior that they are always ready to read immediately
-                    # but reading returns nothing.
-                    raise SerialException(
-                        'device reports readiness to read but returned no data '
-                        '(device disconnected or multiple access on port?)')
-                read.extend(buf)
             except OSError as e:
                 # this is for Python 3.x where select.error is a subclass of
                 # OSError ignore BlockingIOErrors and EINTR. other errors are shown
@@ -570,6 +560,18 @@ class Serial(SerialBase, PlatformSpecific):
                 # see also http://www.python.org/dev/peps/pep-3151/#select
                 if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR):
                     raise SerialException('read failed: {}'.format(e))
+            else:
+                # read should always return some data as select reported it was
+                # ready to read when we get to this point.
+                if not buf:
+                    # Disconnected devices, at least on Linux, show the
+                    # behavior that they are always ready to read immediately
+                    # but reading returns nothing.
+                    raise SerialException(
+                        'device reports readiness to read but returned no data '
+                        '(device disconnected or multiple access on port?)')
+                read.extend(buf)
+
             if timeout.expired():
                 break
         return bytes(read)