gh-97907: use cancellation error from child if possible #133243
+32
−1
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Outdated suggestions cannot be applied.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.
At present when cancelling the result of an :func:
asncio.gather
call, the last child is used to create the cancellation error. If that was not cancelled but another child was, its cancellation message and traceback will be lost.Fix this by using the cancellation error from the first of the children to be cancelled, if any, falling back to the last child only if none have been.