partial clone

other-test-repos/partial-clone.sh

@@ -0,0 +1,94 @@
+#!/usr/bin/env bash
+
+rm -rf partial-clone.tmp
+mkdir -p partial-clone.tmp
+cd partial-clone.tmp
+
+#!/usr/bin/env bash
+set -eu
+
+list-objects() (
+  git rev-list --all --objects
+  echo "master commit SHA: $(git log -1 --format="%H")"
+  echo "mybranch commit SHA: $(git log -1 --format="%H")"
+  git ls-tree master
+  git ls-tree mybranch | grep mybranch
+  git ls-tree master~ | grep root
+)
+
+# Reproducibility.
+export GIT_COMMITTER_NAME='a'
+export GIT_COMMITTER_EMAIL='a'
+export GIT_AUTHOR_NAME='a'
+export GIT_AUTHOR_EMAIL='a'
+export GIT_COMMITTER_DATE='2000-01-01T00:00:00+0000'
+export GIT_AUTHOR_DATE='2000-01-01T00:00:00+0000'
+
+rm -rf server_repo local_repo
+mkdir server_repo
+cd server_repo
+
+# Create repo.
+git init --quiet
+git config --local uploadpack.allowfilter 1
+git config --local uploadpack.allowanysha1inwant 1
+
+# First commit.
+# Directories present in all branches.
+mkdir asdf d2
+printf 'asdf/a' > ./asdf/a
+printf 'asdf/b' > ./asdf/b
+printf 'd2/a' > ./d2/a
+printf 'd2/b' > ./d2/b
+# Present only in root.
+mkdir 'root'
+printf 'root' > ./root/root
+git add .
+git commit -m 'root' --quiet
+
+# Second commit only on master.
+git rm --quiet -r ./root
+mkdir 'master'
+printf 'master' > ./master/master
+git add .
+git commit -m 'master commit' --quiet
+
+# Second commit only on mybranch.
+git checkout -b mybranch --quiet master~
+git rm --quiet -r ./root
+mkdir 'mybranch'
+printf 'mybranch' > ./mybranch/mybranch
+git add .
+git commit -m 'mybranch commit' --quiet
+
+echo "# List and identify all objects"
+list-objects
+echo
+
+# Restore master.
+git checkout --quiet master
+cd ..
+
+# Clone. Don't checkout for now, only .git/ dir.
+# file:// shenanigans:
+# https://stackoverflow.com/questions/47307578/how-to-shallow-clone-a-local-git-repository-with-a-relative-path
+git clone --depth 1 --quiet --no-checkout --filter=blob:none "file://$(pwd)/server_repo" local_repo
+cd local_repo
+
+# List missing objects from master.
+echo "# Missing objects after --no-checkout"
+git rev-list --all --quiet --objects --missing=print
+echo
+
+echo "# Git checkout fails without internet"
+mv ../server_repo ../server_repo.off
+! git checkout master
+echo
+
+echo "# Git checkout fetches the missing directory from internet"
+mv ../server_repo.off ../server_repo
+git checkout master -- asdf/
+echo
+
+echo "# Missing objects after checking out asdf"
+git rev-list --all --quiet --objects --missing=print