manifestdict: drop empty-string argument when creating empty manifest
manifestdict() creates an empty manifestdict, so let's consistently
use that instead of explicitly parsing an empty string (which does
result in an empty manifest).
Check that entry is added to .hg/requires
$ hg --config experimental.manifestv2=True init repo
$ cd repo
$ grep manifestv2 .hg/requires
manifestv2
Set up simple repo
$ echo a > file1
$ echo b > file2
$ echo c > file3
$ hg ci -Aqm 'initial'
$ echo d > file2
$ hg ci -m 'modify file2'
Check that 'hg verify', which uses manifest.readdelta(), works
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
3 files, 2 changesets, 4 total revisions
Check that manifest revlog is smaller than for v1
$ hg debugindex -m
rev offset length base linkrev nodeid p1 p2
0 0 81 0 0 57361477c778 000000000000 000000000000
1 81 33 0 1 aeaab5a2ef74 57361477c778 000000000000