From: John Snow <jsnow@redhat.com>
Date: Tue, 6 Oct 2020 23:58:14 +0000 (-0400)
Subject: python/qemu/qmp.py: Preserve error context on re-raise
X-Git-Tag: v5.2.0-rc0~43^2~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d2b08b79b0d0f1f794b9ed8f3b8fbcbfdfb9e142;p=thirdparty%2Fqemu.git

python/qemu/qmp.py: Preserve error context on re-raise

Use the "from ..." phrasing when re-raising errors to preserve their
initial context, to help aid debugging when things go wrong.

This also silences a pylint 2.6.0+ error.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20201006235817.3280413-18-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
---

diff --git a/python/qemu/qmp.py b/python/qemu/qmp.py
index 9223307ed81..d911999da1f 100644
--- a/python/qemu/qmp.py
+++ b/python/qemu/qmp.py
@@ -181,10 +181,11 @@ class QEMUMonitorProtocol:
                 self.__sock.settimeout(wait)
             try:
                 ret = self.__json_read(only_event=True)
-            except socket.timeout:
-                raise QMPTimeoutError("Timeout waiting for event")
-            except:
-                raise QMPConnectError("Error while reading from socket")
+            except socket.timeout as err:
+                raise QMPTimeoutError("Timeout waiting for event") from err
+            except Exception as err:
+                msg = "Error while reading from socket"
+                raise QMPConnectError(msg) from err
             if ret is None:
                 raise QMPConnectError("Error while reading from socket")
             self.__sock.settimeout(None)