Simon Whitaker <swhitaker@fb.com> [Sun, 01 Oct 2017 12:54:35 +0100] rev 34408
obsmarker: crash more helpfully when metadata fields are >255bytes (issue5681)
Various mutators fail when attempting to write obsmarkers with
metadata fields longer than 255 bytes, since the length of
mwetadata fields is stored in u8s. This change raises a more
helpful error in such circumstances.
Differential Revision: https://phab.mercurial-scm.org/D865