revlog: fix revlogio.packentry corner case
We want to store version information about the revlog in the first
entry of its index. The code in packentry was using some heuristics
to detect whether this was the first entry, but these heuristics could
fail in some cases (e.g. rev 0 was empty; rev 1 descends directly from
the nullid and is stored as a delta).
We now give the revision number to packentry to avoid heuristics.
#!/bin/sh
hg init a
cd a
echo a > a
hg add -n
hg st
hg add
hg st
echo b > b
hg add -n b
hg st
hg add b
hg st
echo % should fail
hg add b
hg st
hg ci -m 0
echo % should fail
hg add a
echo aa > a
hg ci -m 1
hg up 0
echo aaa > a
hg ci -m 2
hg merge
hg st
echo % should fail
hg add a
hg st
hg ci -m merge
echo % issue683
hg rm a
hg st
echo a > a
hg add a
hg st