contrib: don't hardcode path to bash interpreter
Use the env binary to figure out the correct bash to use.
Certain systems ships with an ancient version of bash, but the
user might have installed a newer one that is earlier in $PATH.
For example the current version of Mac OS X ships version 3.2.51
of bash, which does not understand new fancy builtins such as
readarray. A user might install a newer version of bash, use that
as their shell and add that path before bin.
http://mercurial.selenic.com/bts/issue522
In the merge below, the file "foo" has the same contents in both
parents, but if we look at the file-level history, we'll notice that
the version in p1 is an ancestor of the version in p2. This test makes
sure that we'll use the version from p2 in the manifest of the merge
revision.
$ hg init
$ echo foo > foo
$ hg ci -qAm 'add foo'
$ echo bar >> foo
$ hg ci -m 'change foo'
$ hg backout -r tip -m 'backout changed foo'
reverting foo
changeset 2:4d9e78aaceee backs out changeset 1:b515023e500e
$ hg up -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ touch bar
$ hg ci -qAm 'add bar'
$ hg merge --debug
searching for copies back to rev 1
unmatched files in local:
bar
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: bbd179dfa0a7, local: 71766447bdbb+, remote: 4d9e78aaceee
foo: remote is newer -> g
getting foo
updating: foo 1/1 files (100.00%)
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg debugstate | grep foo
n 0 -2 unset foo
$ hg st -A foo
M foo
$ hg ci -m 'merge'
$ hg manifest --debug | grep foo
c6fc755d7e68f49f880599da29f15add41f42f5a 644 foo
$ hg debugindex foo
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 5 ..... 0 2ed2a3912a0b 000000000000 000000000000 (re)
1 5 9 ..... 1 6f4310b00b9a 2ed2a3912a0b 000000000000 (re)
2 14 5 ..... 2 c6fc755d7e68 6f4310b00b9a 000000000000 (re)