Fix upstream merge conflict on 53f0df490f50
Merging upstream commit 53f0df490f50 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 96f52994e5f57f32eebb992acc1f5f1f3a795fcc && \
hg topic upstream-merge && \
hg merge 53f0df490f5044495faea3f55dbba870b3e32129