[WIP v2 0/5] mv: fix out-of-cone file/directory move logic

[Shaoxuan Yuan <shaoxuan.yuan02@gmail.com>]

## Changes since WIP v1 ##

1. Move t7002 tests to the front and turn corresponding tests to 
   test_expect_success along with corresponding commits.

2. Add two tests to t7002.

3. Update check_dir_in_index() and added corresponding documentation.

4. Turn update_mode into enum flags.

5. Use update_sparsity() to replace advise*() function after touching
   sparse contents (this change is INCOMPLETE, NEED FIX).

6. Fix some format issues.

## Limitations ##

This series has not considered moving file from in-cone area to out-of-cone
area *yet*. Moving from in-cone to out-of-cone has not been covered/tested. The
plan is to add the "in-cone to out-of-cone" functionality later, since this 
series is WIP for now.

Shaoxuan Yuan (5):
  t7002: add tests for moving out-of-cone file/directory
  mv: check if out-of-cone file exists in index with SKIP_WORKTREE bit
  mv: check if <destination> exists in index to handle overwriting
  mv: add check_dir_in_index() and solve general dir check issue
  mv: use update_sparsity() after touching sparse contents

 builtin/mv.c                  | 104 +++++++++++++++++++++++++++++--
 t/t7002-mv-sparse-checkout.sh | 114 ++++++++++++++++++++++++++++++++++
 2 files changed, 212 insertions(+), 6 deletions(-)

Range-diff against v1:
4:  1dd2fcb234 ! 1:  485d1e9102 t7002: add tests for moving out-of-cone file/directory
    @@ Commit message
         * 'can move out-of-cone directory with --sparse'
         * 'refuse to move out-of-cone file without --sparse'
         * 'can move out-of-cone file with --sparse'
    +    * 'refuse to move sparse file to existing destination'
    +    * 'move sparse file to existing destination with --force and --sparse'
     
         Signed-off-by: Shaoxuan Yuan <shaoxuan.yuan02@gmail.com>
     
    @@ t/t7002-mv-sparse-checkout.sh: test_expect_success 'refuse to move file to non-s
      	test_cmp expect stderr
      '
      
    -+test_expect_success 'refuse to move out-of-cone directory without --sparse' '
    ++test_expect_failure 'refuse to move out-of-cone directory without --sparse' '
     +	git sparse-checkout disable &&
     +	git reset --hard &&
     +	mkdir folder1 &&
    @@ t/t7002-mv-sparse-checkout.sh: test_expect_success 'refuse to move file to non-s
     +	test_cmp expect stderr
     +'
     +
    -+test_expect_success 'can move out-of-cone directory with --sparse' '
    ++test_expect_failure 'can move out-of-cone directory with --sparse' '
     +	git sparse-checkout disable &&
     +	git reset --hard &&
     +	mkdir folder1 &&
    @@ t/t7002-mv-sparse-checkout.sh: test_expect_success 'refuse to move file to non-s
     +
     +	git mv --sparse folder1 sub 1>actual 2>stderr &&
     +	test_must_be_empty stderr &&
    -+	echo "Please use \"git sparse-checkout reapply\" to reapply the sparsity."\
    -+	>expect &&
    -+	test_cmp actual expect &&
     +
     +	git sparse-checkout reapply &&
     +	test_path_is_dir sub/folder1 &&
     +	test_path_is_file sub/folder1/file1
     +'
     +
    -+test_expect_success 'refuse to move out-of-cone file without --sparse' '
    ++test_expect_failure 'refuse to move out-of-cone file without --sparse' '
     +	git sparse-checkout disable &&
     +	git reset --hard &&
     +	mkdir folder1 &&
    @@ t/t7002-mv-sparse-checkout.sh: test_expect_success 'refuse to move file to non-s
     +	test_cmp expect stderr
     +'
     +
    -+test_expect_success 'can move out-of-cone file with --sparse' '
    ++test_expect_failure 'can move out-of-cone file with --sparse' '
     +	git sparse-checkout disable &&
     +	git reset --hard &&
     +	mkdir folder1 &&
    @@ t/t7002-mv-sparse-checkout.sh: test_expect_success 'refuse to move file to non-s
     +
     +	git mv --sparse folder1/file1 sub 1>actual 2>stderr &&
     +	test_must_be_empty stderr &&
    -+	echo "Please use \"git sparse-checkout reapply\" to reapply the sparsity."\
    -+	>expect &&
    -+	test_cmp actual expect &&
     +
     +	git sparse-checkout reapply &&
     +	! test_path_is_dir sub/folder1 &&
     +	test_path_is_file sub/file1
     +'
    ++
    ++test_expect_failure 'refuse to move sparse file to existing destination' '
    ++	git sparse-checkout disable &&
    ++	git reset --hard &&
    ++	mkdir folder1 &&
    ++	touch folder1/file1 &&
    ++	touch sub/file1 &&
    ++	git add folder1 sub/file1 &&
    ++	git sparse-checkout init --cone &&
    ++	git sparse-checkout set sub &&
    ++
    ++	test_must_fail git mv --sparse folder1/file1 sub 2>stderr &&
    ++	echo "fatal: destination exists, source=folder1/file1, destination=sub/file1" >expect &&
    ++	test_cmp expect stderr
    ++'
    ++
    ++test_expect_failure 'move sparse file to existing destination with --force and --sparse' '
    ++	git sparse-checkout disable &&
    ++	git reset --hard &&
    ++	mkdir folder1 &&
    ++	touch folder1/file1 &&
    ++	touch sub/file1 &&
    ++	echo "overwrite" >folder1/file1 &&
    ++	git add folder1 sub/file1 &&
    ++	git sparse-checkout init --cone &&
    ++	git sparse-checkout set sub &&
    ++
    ++	git mv --sparse --force folder1/file1 sub 2>stderr &&
    ++	test_must_be_empty stderr &&
    ++	echo "overwrite" >expect &&
    ++	test_cmp expect sub/file1
    ++'
     +
      test_done
1:  5cf6b860e3 ! 2:  c99df4fc1a mv: check if out-of-cone file exists in index with SKIP_WORKTREE bit
    @@ builtin/mv.c: int cmd_mv(int argc, const char **argv, const char *prefix)
      				bad = _("bad source");
      		} else if (!strncmp(src, dst, length) &&
      				(dst[length] == 0 || dst[length] == '/')) {
    +
    + ## t/t7002-mv-sparse-checkout.sh ##
    +@@ t/t7002-mv-sparse-checkout.sh: test_expect_failure 'can move out-of-cone directory with --sparse' '
    + 	test_path_is_file sub/folder1/file1
    + '
    + 
    +-test_expect_failure 'refuse to move out-of-cone file without --sparse' '
    ++test_expect_success 'refuse to move out-of-cone file without --sparse' '
    + 	git sparse-checkout disable &&
    + 	git reset --hard &&
    + 	mkdir folder1 &&
    +@@ t/t7002-mv-sparse-checkout.sh: test_expect_failure 'refuse to move out-of-cone file without --sparse' '
    + 	test_cmp expect stderr
    + '
    + 
    +-test_expect_failure 'can move out-of-cone file with --sparse' '
    ++test_expect_success 'can move out-of-cone file with --sparse' '
    + 	git sparse-checkout disable &&
    + 	git reset --hard &&
    + 	mkdir folder1 &&
-:  ---------- > 3:  8f1193188b mv: check if <destination> exists in index to handle overwriting
2:  7b3c931f3f ! 4:  e195bfbc73 mv: add check_dir_in_index() and solve general dir check issue
    @@ Commit message
         errors out with "bad source".
     
         Add a helper check_dir_in_index() function to see if a directory
    -    name exists in the index. Also add a SPARSE_DIRECTORY bit to mark
    +    name exists in the index. Also add a SKIP_WORKTREE_DIR bit to mark
         such directories.
     
         Change the checking logic, so that such <source> directory makes
    @@ Commit message
         instead of "bad source"; also user now can supply a "--sparse" flag so
         this operation can be carried out successfully.
     
    +    Also, as suggested by Derrick [1],
    +    move the in-line definition of "enum update_mode" to the top
    +    of the file and make it use "flags" mode (each state is a different
    +    bit in the word).
    +
    +    [1] https://lore.kernel.org/git/22aadea2-9330-aa9e-7b6a-834585189144@github.com/
    +
         Signed-off-by: Shaoxuan Yuan <shaoxuan.yuan02@gmail.com>
     
      ## builtin/mv.c ##
    +@@ builtin/mv.c: static const char * const builtin_mv_usage[] = {
    + 	NULL
    + };
    + 
    ++enum update_mode {
    ++	BOTH = 0,
    ++	WORKING_DIRECTORY = (1 << 1),
    ++	INDEX = (1 << 2),
    ++	SPARSE = (1 << 3),
    ++	SKIP_WORKTREE_DIR = (1 << 4),
    ++};
    ++
    + #define DUP_BASENAME 1
    + #define KEEP_TRAILING_SLASH 2
    + 
     @@ builtin/mv.c: static int index_range_of_same_dir(const char *src, int length,
      	return last - first;
      }
      
    -+static int check_dir_in_index(const char *dir)
    ++/*
    ++ * Check if an out-of-cone directory should be in the index. Imagine this case
    ++ * that all the files under a directory are marked with 'CE_SKIP_WORKTREE' bit
    ++ * and thus the directory is sparsified.
    ++ *
    ++ * Return 0 if such directory exist (i.e. with any of its contained files not
    ++ * marked with CE_SKIP_WORKTREE, the directory would be present in working tree).
    ++ * Return 1 otherwise.
    ++ */
    ++static int check_dir_in_index(const char *name, int namelen)
     +{
    -+	int ret = 0;
    -+	int length = sizeof(dir) + 1;
    -+	char *substr = malloc(length);
    ++	int ret = 1;
    ++	const char *with_slash = add_slash(name);
    ++	int length = namelen + 1;
     +
    -+	for (int i = 0; i < the_index.cache_nr; i++) {
    -+		memcpy(substr, the_index.cache[i]->name, length);
    -+		memset(substr + length - 1, 0, 1);
    ++	int pos = cache_name_pos(with_slash, length);
    ++	const struct cache_entry *ce;
     +
    -+		if (strcmp(dir, substr) == 0) {
    -+			ret = 1;
    ++	if (pos < 0) {
    ++		pos = -pos - 1;
    ++		if (pos >= the_index.cache_nr)
     +			return ret;
    -+		}
    ++		ce = active_cache[pos];
    ++		if (strncmp(with_slash, ce->name, length))
    ++			return ret;
    ++		if (ce_skip_worktree(ce))
    ++			return ret = 0;
     +	}
    -+	free(substr);
     +	return ret;
     +}
     +
    @@ builtin/mv.c: int cmd_mv(int argc, const char **argv, const char *prefix)
      	};
      	const char **source, **destination, **dest_path, **submodule_gitfile;
     -	enum update_mode { BOTH = 0, WORKING_DIRECTORY, INDEX, SPARSE } *modes;
    -+	enum update_mode { BOTH = 0, WORKING_DIRECTORY, INDEX, SPARSE,
    -+	SPARSE_DIRECTORY } *modes;
    ++	enum update_mode *modes;
      	struct stat st;
      	struct string_list src_for_dst = STRING_LIST_INIT_NODUP;
      	struct lock_file lock_file = LOCK_INIT;
     @@ builtin/mv.c: int cmd_mv(int argc, const char **argv, const char *prefix)
    - 			 */
    + 		if (lstat(src, &st) < 0) {
      
      			int pos = cache_name_pos(src, length);
     +			const char *src_w_slash = add_slash(src);
    @@ builtin/mv.c: int cmd_mv(int argc, const char **argv, const char *prefix)
      				else
      					bad = _("bad source");
      			}
    -+			else if (check_dir_in_index(src_w_slash) &&
    -+			!path_in_sparse_checkout(src_w_slash, &the_index)) {
    -+				modes[i] = SPARSE_DIRECTORY;
    ++			else if (!check_dir_in_index(src, length) &&
    ++					 !path_in_sparse_checkout(src_w_slash, &the_index)) {
    ++				modes[i] = SKIP_WORKTREE_DIR;
     +				goto dir_check;
     +			}
      			/* only error if existence is expected. */
    @@ builtin/mv.c: int cmd_mv(int argc, const char **argv, const char *prefix)
      
     -				modes[i] = WORKING_DIRECTORY;
     +				if (!modes[i])
    -+					modes[i] = WORKING_DIRECTORY;
    ++					modes[i] |= WORKING_DIRECTORY;
      				n = argc + last - first;
      				REALLOC_ARRAY(source, n);
      				REALLOC_ARRAY(destination, n);
    @@ builtin/mv.c: int cmd_mv(int argc, const char **argv, const char *prefix)
      		if (show_only)
      			continue;
     -		if (mode != INDEX && mode != SPARSE && rename(src, dst) < 0) {
    -+		if (mode != INDEX && mode != SPARSE && mode != SPARSE_DIRECTORY &&
    -+		 rename(src, dst) < 0) {
    ++		if (!(mode & (INDEX | SPARSE | SKIP_WORKTREE_DIR)) &&
    ++		 	rename(src, dst) < 0) {
      			if (ignore_errors)
      				continue;
      			die_errno(_("renaming '%s' failed"), src);
    @@ builtin/mv.c: int cmd_mv(int argc, const char **argv, const char *prefix)
      		}
      
     -		if (mode == WORKING_DIRECTORY)
    -+		if (mode == WORKING_DIRECTORY || mode == SPARSE_DIRECTORY)
    ++		if (mode & (WORKING_DIRECTORY | SKIP_WORKTREE_DIR))
      			continue;
      
      		pos = cache_name_pos(src, strlen(src));
    +
    + ## t/t7002-mv-sparse-checkout.sh ##
    +@@ t/t7002-mv-sparse-checkout.sh: test_expect_success 'refuse to move file to non-skip-worktree sparse path' '
    + 	test_cmp expect stderr
    + '
    + 
    +-test_expect_failure 'refuse to move out-of-cone directory without --sparse' '
    ++test_expect_success 'refuse to move out-of-cone directory without --sparse' '
    + 	git sparse-checkout disable &&
    + 	git reset --hard &&
    + 	mkdir folder1 &&
    +@@ t/t7002-mv-sparse-checkout.sh: test_expect_failure 'refuse to move out-of-cone directory without --sparse' '
    + 	test_cmp expect stderr
    + '
    + 
    +-test_expect_failure 'can move out-of-cone directory with --sparse' '
    ++test_expect_success 'can move out-of-cone directory with --sparse' '
    + 	git sparse-checkout disable &&
    + 	git reset --hard &&
    + 	mkdir folder1 &&
3:  4be4c4f34d < -:  ---------- mv: add advise_to_reapply hint for moving file into cone
-:  ---------- > 5:  aa82ba56b0 mv: use update_sparsity() after touching sparse contents
-- 
2.35.1