Avoid crashing the event processing thread on non-utf8 filenames (#812)

* Avoid putting the process in a zombie state when encountering non-unicode filenames

This patch matches the behavior of the python3 branch on python2:
If a file's name is not a valid string in the filesystem's character encoding, then it is processed with a filename string where the invalid characters are encoded as unicode surrogate pairs.

This matches the behavior of os.fsdecode which is used on python 3

https://docs.python.org/3/library/os.html#os.fsdecode

* Update changelog.rst

Co-authored-by: Mickaël Schoentgen <contact@tiger-222.fr>

changelog.rst

@@ -8,6 +8,7 @@ Changelog
 
 202x-xx-xx • `full history <https://github.com/gorakhargosh/watchdog/compare/v0.10.6...python-2.7>`__
 
+- Avoid crashing the event processing thread on non-utf8 filenames (`#811 <https://github.com/gorakhargosh/watchdog/pull/811>`_)
 - [backport 1.0.0] [mac] Regression fixes for native ``fsevents`` (`#717 <https://github.com/gorakhargosh/watchdog/pull/717>`_)
 - [backport 1.0.0] [windows] ``winapi.BUFFER_SIZE`` now defaults to ``64000`` (instead of ``2048``) (`#700 <https://github.com/gorakhargosh/watchdog/pull/700>`_)
 - [backport 1.0.0] [windows] Introduced ``winapi.PATH_BUFFER_SIZE`` (defaults to ``2048``) to keep the old behavior with path-realted functions (`#700 <https://github.com/gorakhargosh/watchdog/pull/700>`_)
@@ -21,7 +22,7 @@ Changelog
 - [backport 2.0.0] [mac] Support coalesced filesystem events (`#734 <https://github.com/gorakhargosh/watchdog/pull/734>`_)
 - [backport 2.0.0] [mac] Drop support for OSX 10.12 and earlier (`#750 <https://github.com/gorakhargosh/watchdog/pull/750>`_)
 - [backport 2.0.0] [mac] Fix an issue when renaming an item changes only the casing (`#750 <https://github.com/gorakhargosh/watchdog/pull/750>`_)
-- Thanks to our beloved contributors: @SamSchott, @bstaletic, @BoboTiG, @CCP-Aporia, @di, @lukassup, @ysard
+- Thanks to our beloved contributors: @SamSchott, @bstaletic, @BoboTiG, @CCP-Aporia, @di, @lukassup, @ysard, @lovasoa
 
 
 0.10.6

src/watchdog/utils/unicode_paths.py

@@ -55,10 +55,13 @@ def encode(path):
 
 def decode(path):
     if isinstance(path, bytes_cls):
+        # Try the filesystem encoding and the fallback encoding.
+        # If all fails, encode invalid characters using surrogate pairs
         try:
             path = path.decode(fs_encoding, 'strict')
         except UnicodeDecodeError:
-            if not platform.is_linux():
-                raise
-            path = path.decode(fs_fallback_encoding, 'strict')
+            try:
+                path = path.decode(fs_fallback_encoding, 'strict')
+            except UnicodeDecodeError:
+                path = path.decode(fs_encoding, 'surrogateescape')
     return path