Fix exception swallowing by Trait attribute access #959
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
When doing
obj.attr_name
on aHasTraits
objectobj
, ifattr_name
doesn't appear in either the class or instance dictionaries, Traits next tries to look it up as a regular Python attribute (via thePyObject_GenericGetAttr
C-API function). If that lookup fails with an exception of any kind, the exception is swallowed and Traits then moves on to try the general prefix-trait machinery. In effect, there's a bareexcept
here, but at C level.This PR modifies the behaviour to replace the bare
except
with anexcept AttributeError
, so that exceptions other thanAttributeError
will no longer be swallowed.The fix itself is easy. Writing a regression test that worked was ... more interesting.
This fixes one case of #946.