copies: filter out copies from non-existent source later in _chain()
_changesetforwardcopies() repeatedly calls _chain(). That is very
expensive because _chain() does lookups in the manifest. I hope to
split up the function in two parts: 1) simple chaining, not
considering end points, and 2) filter out files that don't exist in
the end points (and ping-pong copies/renames).
This patches gets us closer to that by moving the check for
non-existent source later in the function. Now there are no more
checks for "src" and "dst" in the first loop; all the filtering of
invalid copies is done in the second loop. The code also looks much
more consistent now.
No measureable impact on `hg debugpathcopies 4.0 4.8`. That shouldn't
be surprising since the only case we're doing more checks now is in
case of chained copies/renames, which are quire rare in practice.
Differential Revision: https://phab.mercurial-scm.org/D6277
#require svn13
$ cat <<EOF >> $HGRCPATH
> [extensions]
> mq =
> [diff]
> nodates = 1
> [subrepos]
> allowed = true
> svn:allowed = true
> EOF
fn to create new repository, and cd into it
$ mkrepo() {
> hg init $1
> cd $1
> hg qinit
> }
handle svn subrepos safely
$ svnadmin create svn-repo-2499
$ SVNREPOPATH=`pwd`/svn-repo-2499/project
$ SVNREPOURL="`"$PYTHON" $TESTDIR/svnurlof.py \"$SVNREPOPATH\"`"
$ mkdir -p svn-project-2499/trunk
$ svn import -qm 'init project' svn-project-2499 "$SVNREPOURL"
qnew on repo w/svn subrepo
$ mkrepo repo-2499-svn-subrepo
$ svn co "$SVNREPOURL"/trunk sub
Checked out revision 1.
$ echo 'sub = [svn]sub' >> .hgsub
$ hg add .hgsub
$ hg status -S -X '**/format'
A .hgsub
$ hg qnew -m0 0.diff
$ cd sub
$ echo a > a
$ svn add a
A a
$ svn st
A* a (glob)
$ cd ..
$ hg status -S # doesn't show status for svn subrepos (yet)
$ hg qnew -m1 1.diff
abort: uncommitted changes in subrepository "sub"
[255]
$ cd ..