tests/test-merge5

Change revlog.heads to walk the revision graph using revision numbers

On the kernel repo:
$ hg heads -q
           before    after
RevlogNG    1.11     0.52
Revlogv0    0.80     0.69

Since the current code for tags has to find all the heads of the repo,
this also helps there:
$ hg tags
           before    after
RevlogNG    2.35     1.76
Revlogv0    2.04     1.90

#!/bin/sh

mkdir t
cd t
hg init
echo This is file a1 > a
echo This is file b1 > b
hg add a b
hg commit -m "commit #0" -d "1000000 0"
echo This is file b22 > b
hg commit -m"comment #1" -d "1000000 0"
hg update 0
rm b
hg commit -A -m"comment #2" -d "1000000 0"
# in theory, we shouldn't need the "-y" below, but it prevents
# this test from hanging when "hg update" erroneously prompts the
# user for "keep or delete"
hg update -y 1

exit 0