override: Catch type error

handler() should either return bytes or -2 or -3.
Explicitly raise ValueError or TypeError to silence mypy.

Signed-off-by: Philipp Hahn <hahn@univention.de>

libvirt-override-virStream.py

@@ -200,7 +200,7 @@
             if got == -2:
                 raise libvirtError("cannot use sparseRecvAll with "
                                    "nonblocking stream")
-            if got == -3:
+            elif got == -3:
                 length = self.recvHole()
                 if length is None:
                     self.abort()
@@ -210,6 +210,10 @@
                     self.abort()
                     raise RuntimeError("holeHandler handler returned %d" % ret)
                 continue
+            elif isinstance(got, int):
+                raise ValueError(got)
+            elif not isinstance(got, bytes):
+                raise TypeError(type(got))
 
             if len(got) == 0:
                 break