grep: reuse getrenamedfn() from scmutil
My motivation is to reduce uses of filectx.renamed(). Reusing
scmutil.getrenamedfn() also means that we get some caching of copy
information per file and revision. I don't think that matters for `hg
grep` (I doubt it speeds up significantly, and I doubt it wastes
significant memory), but I'm not sure.
Differential Revision: https://phab.mercurial-scm.org/D6022
$ cat >> $HGRCPATH <<EOF
> [extensions]
> drawdag=$TESTDIR/drawdag.py
> bruterebase=$TESTDIR/bruterebase.py
> [experimental]
> evolution.createmarkers=True
> evolution.allowunstable=True
> EOF
$ init() {
> N=`expr ${N:-0} + 1`
> cd $TESTTMP && hg init repo$N && cd repo$N
> hg debugdrawdag
> }
Source looks like "N"
$ init <<'EOS'
> C D
> |\|
> A B Z
> EOS
$ hg debugbruterebase 'all()-Z' Z
A: A':Z
B: B':Z
AB: A':Z B':Z
C: ABORT: cannot rebase 3:a35c07e8a2a4 without moving at least one of its parents
AC: A':Z C':A'B
BC: B':Z C':B'A
ABC: A':Z B':Z C':A'B'
D: D':Z
AD: A':Z D':Z
BD: B':Z D':B'
ABD: A':Z B':Z D':B'
CD: ABORT: cannot rebase 3:a35c07e8a2a4 without moving at least one of its parents
ACD: A':Z C':A'B D':Z
BCD: B':Z C':B'A D':B'
ABCD: A':Z B':Z C':A'B' D':B'
Moving backwards
$ init <<'EOS'
> C
> |\
> A B
> |
> Z
> EOS
$ hg debugbruterebase 'all()-Z' Z
B: B':Z
A:
BA: B':Z
C: ABORT: cannot rebase 3:b8d7149b562b without moving at least one of its parents
BC: B':Z C':B'A
AC:
BAC: B':Z C':B'A