Fix diverting std{out,err} when running frozen

When running frozen (ie, a Windows exe) we override sys.std{out,err} so the
output can be diverted to a file.  There was a problem with logging.Logger
instances which would get a reference to the original objecs and then find
then closed after our second replacement.

The solution is to override them very early, and this MUST be done BEFORE
importing the log module.  Then, when the file property is set the StringIO
will be drained into the file.

bin/blink

@@ -3,15 +3,12 @@
 import os
 import sys
 
-from application import log
-
 
 def except_hook(exception_type, exception_value, traceback):
     sys.__excepthook__(exception_type, exception_value, traceback)
 
 sys.excepthook = except_hook  # pyqt5 (>=5.5) will abort if an exception happens in python code when called from Qt, unless we define this
 
-log.level.current = log.level.WARNING
 
 frozen = hasattr(sys, 'frozen')
 
@@ -33,7 +30,35 @@ if os.path.basename(script_dir) == 'bin' and os.path.exists(os.path.join(parent_
 
 if frozen:
     from StringIO import StringIO
-    sys.stdout = sys.stderr = StringIO()
+
+    class FakeStdout(object):
+        def __init__(self):
+            self._io = StringIO()
+            self._file = None
+
+        @property
+        def file(self):
+            return self._file
+
+        @file.setter
+        def file(self, f):
+            f.write(self._io.getvalue())
+            self._io.close()
+            self._file = f
+
+        def __getattr__(self, name):
+            if self._file is not None:
+                return getattr(self._file, name)
+            else:
+                return getattr(self._io, name)
+
+    sys.stdout = sys.stderr = FakeStdout()
+
+
+# Import log last so the created StreamHandler instances have references
+# to the replaced sys.std{out,err}
+from application import log
+log.level.current = log.level.WARNING
 
 
 if __name__ == '__main__':

blink/__init__.py

@@ -45,11 +45,8 @@ __all__ = ['Blink']
 
 
 if hasattr(sys, 'frozen'):
-    output = sys.stdout
     makedirs(ApplicationData.get('logs'))
-    sys.stdout = sys.stderr = open(ApplicationData.get('logs/output.log'), 'a', 0)
-    sys.stdout.write(output.getvalue())
-    output.close()
+    sys.stdout.file = open(ApplicationData.get('logs/output.log'), 'a', 0)
 
 
 class IPAddressMonitor(object):