python: Improve error handling.

* NEWS: Update.
* lang/python/src/core.py (Context.__read__): New helper function.
(Context.encrypt): Attach partial results to exceptions.
(Context.decrypt): Likewise.
(Context.sign): Likewise.
(Context.verify): Likewise.
* lang/python/src/errors.py (GpgError): Move the core of GPGMEError to
this class, add a nicer interface for it.  This makes the errors
thrown by this library more uniform, and allows us to track the
underlying error in synthesized high-level errors.
(GPGMEError): Simplify.
(...): Make sure to call the parent classes' constructor in all other
classes.
--

Attach partial results to errors.  Some operations return results even
though they signal an error.  Of course this information must be taken
with a grain of salt.  But often, this information is useful for
diagnostic uses or to give the user feedback.  Since the normal
control flow is disrupted by the exception, the callee can no longer
return results, hence we attach them to the exception objects.

GnuPG-bug-id: 3271
Signed-off-by: Justus Winter <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index b4a0d883..e193e003 100644
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,7 @@ Noteworthy changes in version 1.9.1 (unreleased)
  cpp: Signature::isDeVs        NEW.
  py: DecryptResult EXTENDED: New boolean field 'is_de_vs'.
  py: Signature     EXTENDED: New boolean field 'is_de_vs'.
+ py: GpgError      EXTENDED: Partial results in 'results'.
 
 Noteworthy changes in version 1.9.0 (2017-03-28)
 ------------------------------------------------