Merge branch 'bc/sha1-256-interop-02'

The code to maintain mapping between object names in multiple hash
functions is being added, written in Rust.

* bc/sha1-256-interop-02:
  object-file-convert: always make sure object ID algo is valid
  rust: add a small wrapper around the hashfile code
  rust: add a new binary object map format
  rust: add functionality to hash an object
  rust: add a build.rs script for tests
  rust: fix linking binaries with cargo
  hash: expose hash context functions to Rust
  write-or-die: add an fsync component for the object map
  csum-file: define hashwrite's count as a uint32_t
  rust: add additional helpers for ObjectID
  hash: add a function to look up hash algo structs
  rust: add a hash algorithm abstraction
  rust: add a ObjectID struct
  hash: use uint32_t for object_id algorithm
  conversion: don't crash when no destination algo
  repository: require Rust support for interoperability

6 files changed, 70 insertions, 32 deletions

diff --git a/t/t1006-cat-file.sh b/t/t1006-cat-file.sh
index 5499be8dc9..8e2c52652c 100755
--- a/t/t1006-cat-file.sh
+++ b/t/t1006-cat-file.sh
@@ -241,10 +241,16 @@ hello_content="Hello World"
 hello_size=$(strlen "$hello_content")
 hello_oid=$(echo_without_newline "$hello_content" | git hash-object --stdin)
 
-test_expect_success "setup" '
+test_expect_success "setup part 1" '
 	git config core.repositoryformatversion 1 &&
-	git config extensions.objectformat $test_hash_algo &&
-	git config extensions.compatobjectformat $test_compat_hash_algo &&
+	git config extensions.objectformat $test_hash_algo
+'
+
+test_expect_success RUST 'compat setup' '
+	git config extensions.compatobjectformat $test_compat_hash_algo
+'
+
+test_expect_success 'setup part 2' '
 	echo_without_newline "$hello_content" > hello &&
 	git update-index --add hello &&
 	echo_without_newline "$hello_content" > "path with spaces" &&
@@ -273,9 +279,13 @@ run_blob_tests () {
     '
 }
 
-hello_compat_oid=$(git rev-parse --output-object-format=$test_compat_hash_algo $hello_oid)
 run_blob_tests $hello_oid
-run_blob_tests $hello_compat_oid
+
+if test_have_prereq RUST
+then
+	hello_compat_oid=$(git rev-parse --output-object-format=$test_compat_hash_algo $hello_oid)
+	run_blob_tests $hello_compat_oid
+fi
 
 test_expect_success '--batch-check without %(rest) considers whole line' '
 	echo "$hello_oid blob $hello_size" >expect &&
@@ -286,62 +296,76 @@ test_expect_success '--batch-check without %(rest) considers whole line' '
 '
 
 tree_oid=$(git write-tree)
-tree_compat_oid=$(git rev-parse --output-object-format=$test_compat_hash_algo $tree_oid)
 tree_size=$((2 * $(test_oid rawsz) + 13 + 24))
-tree_compat_size=$((2 * $(test_oid --hash=compat rawsz) + 13 + 24))
 tree_pretty_content="100644 blob $hello_oid	hello${LF}100755 blob $hello_oid	path with spaces${LF}"
-tree_compat_pretty_content="100644 blob $hello_compat_oid	hello${LF}100755 blob $hello_compat_oid	path with spaces${LF}"
 
 run_tests 'tree' $tree_oid "" $tree_size "" "$tree_pretty_content"
-run_tests 'tree' $tree_compat_oid "" $tree_compat_size "" "$tree_compat_pretty_content"
 run_tests 'blob' "$tree_oid:hello" "100644" $hello_size "" "$hello_content" $hello_oid
-run_tests 'blob' "$tree_compat_oid:hello" "100644" $hello_size "" "$hello_content" $hello_compat_oid
 run_tests 'blob' "$tree_oid:path with spaces" "100755" $hello_size "" "$hello_content" $hello_oid
-run_tests 'blob' "$tree_compat_oid:path with spaces" "100755" $hello_size "" "$hello_content" $hello_compat_oid
+
+if test_have_prereq RUST
+then
+	tree_compat_oid=$(git rev-parse --output-object-format=$test_compat_hash_algo $tree_oid)
+	tree_compat_size=$((2 * $(test_oid --hash=compat rawsz) + 13 + 24))
+	tree_compat_pretty_content="100644 blob $hello_compat_oid	hello${LF}100755 blob $hello_compat_oid	path with spaces${LF}"
+
+	run_tests 'tree' $tree_compat_oid "" $tree_compat_size "" "$tree_compat_pretty_content"
+	run_tests 'blob' "$tree_compat_oid:hello" "100644" $hello_size "" "$hello_content" $hello_compat_oid
+	run_tests 'blob' "$tree_compat_oid:path with spaces" "100755" $hello_size "" "$hello_content" $hello_compat_oid
+fi
 
 commit_message="Initial commit"
 commit_oid=$(echo_without_newline "$commit_message" | git commit-tree $tree_oid)
-commit_compat_oid=$(git rev-parse --output-object-format=$test_compat_hash_algo $commit_oid)
 commit_size=$(($(test_oid hexsz) + 137))
-commit_compat_size=$(($(test_oid --hash=compat hexsz) + 137))
 commit_content="tree $tree_oid
 author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> $GIT_AUTHOR_DATE
 committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
 
 $commit_message"
 
-commit_compat_content="tree $tree_compat_oid
+run_tests 'commit' $commit_oid "" $commit_size "$commit_content" "$commit_content"
+
+if test_have_prereq RUST
+then
+	commit_compat_oid=$(git rev-parse --output-object-format=$test_compat_hash_algo $commit_oid)
+	commit_compat_size=$(($(test_oid --hash=compat hexsz) + 137))
+	commit_compat_content="tree $tree_compat_oid
 author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> $GIT_AUTHOR_DATE
 committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
 
 $commit_message"
 
-run_tests 'commit' $commit_oid "" $commit_size "$commit_content" "$commit_content"
-run_tests 'commit' $commit_compat_oid "" $commit_compat_size "$commit_compat_content" "$commit_compat_content"
+	run_tests 'commit' $commit_compat_oid "" $commit_compat_size "$commit_compat_content" "$commit_compat_content"
+fi
 
 tag_header_without_oid="type blob
 tag hellotag
 tagger $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>"
 tag_header_without_timestamp="object $hello_oid
 $tag_header_without_oid"
-tag_compat_header_without_timestamp="object $hello_compat_oid
-$tag_header_without_oid"
 tag_description="This is a tag"
 tag_content="$tag_header_without_timestamp 0 +0000
 
 $tag_description"
-tag_compat_content="$tag_compat_header_without_timestamp 0 +0000
-
-$tag_description"
 
 tag_oid=$(echo_without_newline "$tag_content" | git hash-object -t tag --stdin -w)
 tag_size=$(strlen "$tag_content")
 
-tag_compat_oid=$(git rev-parse --output-object-format=$test_compat_hash_algo $tag_oid)
-tag_compat_size=$(strlen "$tag_compat_content")
-
 run_tests 'tag' $tag_oid "" $tag_size "$tag_content" "$tag_content"
-run_tests 'tag' $tag_compat_oid "" $tag_compat_size "$tag_compat_content" "$tag_compat_content"
+
+if test_have_prereq RUST
+then
+	tag_compat_header_without_timestamp="object $hello_compat_oid
+$tag_header_without_oid"
+	tag_compat_content="$tag_compat_header_without_timestamp 0 +0000
+
+$tag_description"
+
+	tag_compat_oid=$(git rev-parse --output-object-format=$test_compat_hash_algo $tag_oid)
+	tag_compat_size=$(strlen "$tag_compat_content")
+
+	run_tests 'tag' $tag_compat_oid "" $tag_compat_size "$tag_compat_content" "$tag_compat_content"
+fi
 
 test_expect_success "Reach a blob from a tag pointing to it" '
 	echo_without_newline "$hello_content" >expect &&
@@ -590,7 +614,8 @@ flush"
 }
 
 batch_tests $hello_oid $tree_oid $tree_size $commit_oid $commit_size "$commit_content" $tag_oid $tag_size "$tag_content"
-batch_tests $hello_compat_oid $tree_compat_oid $tree_compat_size $commit_compat_oid $commit_compat_size "$commit_compat_content" $tag_compat_oid $tag_compat_size "$tag_compat_content"
+
+test_have_prereq RUST && batch_tests $hello_compat_oid $tree_compat_oid $tree_compat_size $commit_compat_oid $commit_compat_size "$commit_compat_content" $tag_compat_oid $tag_compat_size "$tag_compat_content"
 
 
 test_expect_success FUNNYNAMES 'setup with newline in input' '
@@ -1236,7 +1261,10 @@ test_expect_success 'batch-check with a submodule' '
 	test_unconfig extensions.compatobjectformat &&
 	printf "160000 commit $(test_oid deadbeef)\tsub\n" >tree-with-sub &&
 	tree=$(git mktree <tree-with-sub) &&
-	test_config extensions.compatobjectformat $test_compat_hash_algo &&
+	if test_have_prereq RUST
+	then
+		test_config extensions.compatobjectformat $test_compat_hash_algo
+	fi &&
 
 	git cat-file --batch-check >actual <<-EOF &&
 	$tree:sub
diff --git a/t/t1016-compatObjectFormat.sh b/t/t1016-compatObjectFormat.sh
index 0efce53f3a..92d48b96a1 100755
--- a/t/t1016-compatObjectFormat.sh
+++ b/t/t1016-compatObjectFormat.sh
@@ -8,6 +8,12 @@ test_description='Test how well compatObjectFormat works'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-gpg.sh
 
+if ! test_have_prereq RUST
+then
+	skip_all='interoperability requires a Git built with Rust'
+	test_done
+fi
+
 # All of the follow variables must be defined in the environment:
 # GIT_AUTHOR_NAME
 # GIT_AUTHOR_EMAIL
diff --git a/t/t1500-rev-parse.sh b/t/t1500-rev-parse.sh
index 7739ab611b..98c5a772bd 100755
--- a/t/t1500-rev-parse.sh
+++ b/t/t1500-rev-parse.sh
@@ -208,7 +208,7 @@ test_expect_success 'rev-parse --show-object-format in repo' '
 '
 
 
-test_expect_success 'rev-parse --show-object-format in repo with compat mode' '
+test_expect_success RUST 'rev-parse --show-object-format in repo with compat mode' '
 	mkdir repo &&
 	(
 		sane_unset GIT_DEFAULT_HASH &&
diff --git a/t/t9305-fast-import-signatures.sh b/t/t9305-fast-import-signatures.sh
index 022dae02e4..a5406793f7 100755
--- a/t/t9305-fast-import-signatures.sh
+++ b/t/t9305-fast-import-signatures.sh
@@ -70,7 +70,7 @@ test_expect_success GPGSSH 'strip SSH signature with --signed-commits=strip' '
 	test_must_be_empty log
 '
 
-test_expect_success GPG 'setup a commit with dual OpenPGP signatures on its SHA-1 and SHA-256 formats' '
+test_expect_success RUST,GPG 'setup a commit with dual OpenPGP signatures on its SHA-1 and SHA-256 formats' '
 	# Create a signed SHA-256 commit
 	git init --object-format=sha256 explicit-sha256 &&
 	git -C explicit-sha256 config extensions.compatObjectFormat sha1 &&
@@ -91,7 +91,7 @@ test_expect_success GPG 'setup a commit with dual OpenPGP signatures on its SHA-
 	test_grep -E "^gpgsig-sha256 " out
 '
 
-test_expect_success GPG 'strip both OpenPGP signatures with --signed-commits=warn-strip' '
+test_expect_success RUST,GPG 'strip both OpenPGP signatures with --signed-commits=warn-strip' '
 	git -C explicit-sha256 fast-export --signed-commits=verbatim dual-signed >output &&
 	test_grep -E "^gpgsig sha1 openpgp" output &&
 	test_grep -E "^gpgsig sha256 openpgp" output &&
diff --git a/t/t9350-fast-export.sh b/t/t9350-fast-export.sh
index 3d153a4805..784d68b6e5 100755
--- a/t/t9350-fast-export.sh
+++ b/t/t9350-fast-export.sh
@@ -972,7 +972,7 @@ test_expect_success 'fast-export handles --end-of-options' '
 	test_cmp expect actual
 '
 
-test_expect_success GPG 'setup a commit with dual signatures on its SHA-1 and SHA-256 formats' '
+test_expect_success GPG,RUST 'setup a commit with dual signatures on its SHA-1 and SHA-256 formats' '
 	# Create a signed SHA-256 commit
 	git init --object-format=sha256 explicit-sha256 &&
 	git -C explicit-sha256 config extensions.compatObjectFormat sha1 &&
@@ -993,7 +993,7 @@ test_expect_success GPG 'setup a commit with dual signatures on its SHA-1 and SH
 	test_grep -E "^gpgsig-sha256 " out
 '
 
-test_expect_success GPG 'export and import of doubly signed commit' '
+test_expect_success GPG,RUST 'export and import of doubly signed commit' '
 	git -C explicit-sha256 fast-export --signed-commits=verbatim dual-signed >output &&
 	test_grep -E "^gpgsig sha1 openpgp" output &&
 	test_grep -E "^gpgsig sha256 openpgp" output &&
diff --git a/t/test-lib.sh b/t/test-lib.sh
index dd12b0bdb6..70fd3e9baf 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1901,6 +1901,10 @@ test_lazy_prereq LONG_IS_64BIT '
 	test 8 -le "$(build_option sizeof-long)"
 '
 
+test_lazy_prereq RUST '
+	test "$(build_option rust)" = enabled
+'
+
 test_lazy_prereq TIME_IS_64BIT 'test-tool date is64bit'
 test_lazy_prereq TIME_T_IS_64BIT 'test-tool date time_t-is64bit'