[qemu-xen staging] python/qmp.py: add QMPProtocolError

[patchbot@xxxxxxx]

commit 84dcdf0887cdaaba7300442482c99e5064865a2d
Author:     John Snow <jsnow@xxxxxxxxxx>
AuthorDate: Fri Jul 10 01:22:10 2020 -0400
Commit:     Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
CommitDate: Tue Jul 14 22:22:22 2020 +0200

    python/qmp.py: add QMPProtocolError
    
    In the case that we receive a reply but are unable to understand it,
    use this exception name to indicate that case.
    
    Signed-off-by: John Snow <jsnow@xxxxxxxxxx>
    Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
    Reviewed-by: Kevin Wolf <kwolf@xxxxxxxxxx>
    Message-Id: <20200710052220.3306-7-jsnow@xxxxxxxxxx>
    Signed-off-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
---
 python/qemu/qmp.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/python/qemu/qmp.py b/python/qemu/qmp.py
index 1ae36050a4..7935dababb 100644
--- a/python/qemu/qmp.py
+++ b/python/qemu/qmp.py
@@ -62,6 +62,12 @@ class QMPTimeoutError(QMPError):
     """
 
 
+class QMPProtocolError(QMPError):
+    """
+    QMP protocol error; unexpected response
+    """
+
+
 class QMPResponseError(QMPError):
     """
     Represents erroneous QMP monitor reply
@@ -266,6 +272,10 @@ class QEMUMonitorProtocol:
         ret = self.cmd(cmd, kwds)
         if 'error' in ret:
             raise QMPResponseError(ret)
+        if 'return' not in ret:
+            raise QMPProtocolError(
+                "'return' key not found in QMP response '{}'".format(str(ret))
+            )
         return cast(QMPReturnValue, ret['return'])
 
     def pull_event(self, wait=False):
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#staging