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 unix-permissions no-root
initial setup
$ cat << EOF >> $HGRCPATH
> [ui]
> ssh="$PYTHON" "$TESTDIR/dummyssh"
> EOF
repository itself is non-readable
---------------------------------
$ hg init no-read
$ hg id ssh://user@dummy/no-read
000000000000
$ chmod a-rx no-read
$ hg id ssh://user@dummy/no-read
remote: abort: Permission denied: *$TESTTMP/no-read/.hg* (glob)
abort: no suitable response from remote hg!
[255]
special case files are visible, but unreadable
----------------------------------------------
This is "similar" to the test above, but the directory is "traversable". This
seems an unexpected case in real life, but we test it anyway.
$ hg init other
$ hg id ssh://user@dummy/other
000000000000
$ for item in `find other | sort -r` ; do
> chmod a-r $item
> done
$ hg id ssh://user@dummy/other
remote: abort: Permission denied: '$TESTTMP/other/.hg/requires'
abort: no suitable response from remote hg!
[255]
directory toward the repository is read only
--------------------------------------------
$ mkdir deep
$ hg init deep/nested
$ hg id ssh://user@dummy/deep/nested
000000000000
$ chmod a-rx deep
$ hg id ssh://user@dummy/deep/nested
remote: abort: Permission denied: *$TESTTMP/deep/nested/.hg* (glob)
abort: no suitable response from remote hg!
[255]
repository has wrong requirement
--------------------------------
$ hg init repo-future
$ hg id ssh://user@dummy/repo-future
000000000000
$ echo flying-car >> repo-future/.hg/requires
$ hg id ssh://user@dummy/repo-future
remote: abort: repository requires features unknown to this Mercurial: flying-car!
remote: (see https://mercurial-scm.org/wiki/MissingRequirement for more information)
abort: no suitable response from remote hg!
[255]