bpo-43977: Properly update the tp_flags
of existing subclasses when their parents are register
'd
#26864
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Outdated suggestions cannot be applied.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.
Currently, the
Py_TPFLAGS_MAPPING
andPy_TPFLAGS_SEQUENCE
flags aren't set correctly on child classes created before their parent is registered as aMapping
orSequence
.When setting these flags, recurse through the tree of existing subclasses and set their flags too.
https://bugs.python.org/issue43977