Fix upstream merge conflict on 53547fd552a8
Merging upstream commit 53547fd552a8 gives a conflict.
A human being has to perform merge and resolution for the automatic merge process to resume.
Command for clean conflict reproduction:
hg pull
hg --config command.update.check=abort update 78977c03f81d2f02ed7f4ef83724b0f72ef63924 && \
hg topic upstream-merge && \
hg merge 53547fd552a83711417ba44f2dd18529f405e688