bpo-33274: Compliance with DOM L1: return removed attribute

[arikrupnik]

W3C DOM Level 1[1] requires removeAttributeNode() to return the removed node:

removeAttributeNode: Removes the specified attribute.
Return Value: The Attr node that was removed.

Current implementation returns None.

[1]https://www.w3.org/TR/1998/REC-DOM-Level-1-19981001/level-one-core.html#method-removeAttributeNode

https://bugs.python.org/issue33274

[the-knights-who-say-ni]

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[ned-deily]

@arikrupnik, Thanks for your PR. I see that additions to the PR have been requested on the bug tracker. Please note you should make the PR against the "master" branch, not the "3.6" branch. If a core developer decides to merge the PR to master, they will also decide whether to backport the change to other branches. Thus, I'm closing this PR against 3.6.

https://devguide.python.org/pullrequest/

[arikrupnik]

Thank you @ned-deily. Is it the practice in CPython to open new PRs rather than updating existing ones if one pushes additional commits to the branch?

[terryjreedy]

When a PR is made against the wrong branch, yes.

[arikrupnik]

New PR here: #7465

[ned-deily]

@arikrupnik It's fine to push additional commits to an open PR. But as @terryjreedy notes, the issue here was that the target cpython branch was incorrect and, while I have since found that you can edit the PR to change the target branch, as a practical matter I don't think that would ever be useful with the main cpython branches.