It's possible for relative_to_absolute to be undefined when injesting a BitBucket diff node. This object is already a defaultdict, we just had the wrong default type.
<rdar://problem/129026771>
Pull request: https://github.com/WebKit/WebKit/pull/29338
Committed 279550@main (8c9b24b1bc21): <https://commits.webkit.org/279550@main> Reviewed commits have been landed. Closing PR #29338 and removing active labels.
Committed 272448.1060@safari-7618-branch (fd48bee47093): <https://commits.webkit.org/272448.1060@safari-7618-branch> Reviewed commits have been landed. Closing PR #1314 and removing active labels.