Merge pull request #120 from davidlatwe/improve-subprocessing

Better subprocess listening experience

allzpark/allzparkconfig.py

@@ -126,3 +126,48 @@ def themes():
 
     """
     return []
+
+
+def subprocess_encoding():
+    """Codec that should be used to decode subprocess stdout/stderr
+
+    See https://docs.python.org/3/library/codecs.html#standard-encodings
+
+    Returns:
+        str: name of codec
+
+    """
+    # nerdvegas/rez sets `encoding='utf-8'` when `universal_newlines=True` and
+    # `encoding` is not in Popen kwarg.
+    return "utf-8"
+
+
+def unicode_decode_error_handler():
+    """Error handler for handling UnicodeDecodeError in subprocess
+
+    See https://docs.python.org/3/library/codecs.html#error-handlers
+
+    Returns:
+        str: name of registered error handler
+
+    """
+    import codecs
+    import locale
+
+    def decode_with_preferred_encoding(exception):
+        encoding = locale.getpreferredencoding(do_setlocale=False)
+        invalid_bytes = exception.object[exception.start:]
+
+        text = invalid_bytes.decode(encoding,
+                                    # second fallback
+                                    errors="backslashreplace")
+
+        return text, len(exception.object)
+
+    handler_name = "decode_with_preferred_encoding"
+    try:
+        codecs.lookup_error(handler_name)
+    except LookupError:
+        codecs.register_error(handler_name, decode_with_preferred_encoding)
+
+    return handler_name

allzpark/control.py

@@ -1,6 +1,7 @@
 """Orchestrates view.py and model.py"""
 
 import os
+import sys
 import time
 import errno
 import shutil
@@ -1193,6 +1194,14 @@ def _execute(self):
             "parent_environ": None,
             "startupinfo": startupinfo
         }
+        if rez.project == "rez":
+            # bleeding-rez adds `universal_newlines=True` when spawning shell,
+            # nerdvegas/rez doesn't.
+            kwargs["universal_newlines"] = True
+
+        if sys.version_info[:2] >= (3, 6):
+            kwargs["encoding"] = allzparkconfig.subprocess_encoding()
+            kwargs["errors"] = allzparkconfig.unicode_decode_error_handler()
 
         context = self.context