Hi Peff,
On Tue, 16 Feb 2021, Jeff King wrote:
> The perf suite gets confused when test_perf_default_repo is pointed at a
> worktree (which includes when it is run from within a worktree at all,
> since the default is to use the current repository).
>
> Here's an example:
>
> $ git worktree add ~/foo
> Preparing worktree (new branch 'foo')
> HEAD is now at 328c109303 The eighth batch
> $ cd ~/foo
> $ make
> [...build output...]
> $ cd t/perf
> $ ./p0000-perf-lib-sanity.sh -v -i
> [...]
> perf 1 - test_perf_default_repo works:
> running:
> foo=$(git rev-parse HEAD) &&
> test_export foo
>
> fatal: ambiguous argument 'HEAD': unknown revision or path not in the working tree.
> Use '--' to separate paths from revisions, like this:
> 'git <command> [<revision>...] -- [<file>...]'
>
> The problem is that we didn't copy all of the necessary files from the
> source repository (in this case we got HEAD, but we have no refs!). We
> discover the git-dir with "rev-parse --git-dir", but this points to the
> worktree's partial repository in .../.git/worktrees/foo.
>
> That partial repository has a "commondir" file which points to the main
> repository, where the actual refs are stored, but we don't copy it. This
> is the correct thing to do, though! If we did copy it, then our scratch
> test repo would be pointing back to the original main repo, and any ref
> updates we made in the tests would impact that original repo.
>
> Instead, we need to either:
>
> 1. Make a scratch copy of the original main repo (in addition to the
> worktree repo), and point the scratch worktree repo's commondir at
> it. This preserves the original relationship, but it's doubtful any
> script really cares (if they are testing worktree performance,
> they'd probably make their own worktrees). And it's trickier to get
> right.
>
> 2. Collapse the main and worktree repos into a single scratch repo.
> This can be done by copying everything from both, preferring any
> files from the worktree repo.
>
> This patch does the second one. With this applied, the example above
> results in p0000 running successfully.
>
> Reported-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
> Signed-off-by: Jeff King <peff@xxxxxxxx>
> ---
I think you'll also need the equivalent of:
-- snip --
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index 22d727cef83..0949c360ec4 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -84,7 +84,7 @@ test_perf_create_repo_from () {
cp -R "$objects_dir" "$repo/.git/"; } &&
for stuff in "$source_git"/*; do
case "$stuff" in
- */objects|*/hooks|*/config|*/commondir)
+ */objects|*/hooks|*/config|*/commondir|*/gitdir)
;;
*)
cp -R "$stuff" "$repo/.git/" || exit 1
-- snap --
> Having written that, it occurs to me that an even simpler solution is to
> just always use the commondir as the source of the scratch repo. It does
> not produce the same outcome, but the point is generally just to find a
> suitable starting point for a repository. Grabbing the main repo instead
> of one of its worktrees is probably OK for most tests.
Good point: we probably also need to exclude `*/worktrees/*`, but that is
a bit trickier as we would not want to exclude, say,
`refs/heads/worktrees/cleanup`.
Ciao,
Dscho
>
> t/perf/perf-lib.sh | 31 ++++++++++++++++++++++---------
> 1 file changed, 22 insertions(+), 9 deletions(-)
>
> diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
> index e385c6896f..1226be4005 100644
> --- a/t/perf/perf-lib.sh
> +++ b/t/perf/perf-lib.sh
> @@ -70,27 +70,40 @@ test_perf_do_repo_symlink_config_ () {
> test_have_prereq SYMLINKS || git config core.symlinks false
> }
>
> +test_perf_copy_repo_contents () {
> + for stuff in "$1"/*
> + do
> + case "$stuff" in
> + */objects|*/hooks|*/config|*/commondir)
> + ;;
> + *)
> + cp -R "$stuff" "$repo/.git/" || exit 1
> + ;;
> + esac
> + done
> +}
> +
> test_perf_create_repo_from () {
> test "$#" = 2 ||
> BUG "not 2 parameters to test-create-repo"
> repo="$1"
> source="$2"
> source_git="$("$MODERN_GIT" -C "$source" rev-parse --git-dir)"
> objects_dir="$("$MODERN_GIT" -C "$source" rev-parse --git-path objects)"
> + common_dir="$("$MODERN_GIT" -C "$source" rev-parse --git-common-dir)"
> mkdir -p "$repo/.git"
> (
> cd "$source" &&
> { cp -Rl "$objects_dir" "$repo/.git/" 2>/dev/null ||
> cp -R "$objects_dir" "$repo/.git/"; } &&
> - for stuff in "$source_git"/*; do
> - case "$stuff" in
> - */objects|*/hooks|*/config|*/commondir)
> - ;;
> - *)
> - cp -R "$stuff" "$repo/.git/" || exit 1
> - ;;
> - esac
> - done
> +
> + # common_dir must come first here, since we want source_git to
> + # take precedence and overwrite any overlapping files
> + test_perf_copy_repo_contents "$common_dir"
> + if test "$source_git" != "$common_dir"
> + then
> + test_perf_copy_repo_contents "$source_git"
> + fi
> ) &&
> (
> cd "$repo" &&
> --
> 2.30.1.989.g5e01c2f281
>
>
