merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373

Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'

1 files changed, 1867 insertions, 0 deletions

diff --git a/third_party/git/cache.h b/third_party/git/cache.h
new file mode 100644
index 000000000000..b1da1ab08faa
--- /dev/null
+++ b/third_party/git/cache.h
@@ -0,0 +1,1867 @@
+#ifndef CACHE_H
+#define CACHE_H
+
+#include "git-compat-util.h"
+#include "strbuf.h"
+#include "hashmap.h"
+#include "list.h"
+#include "advice.h"
+#include "gettext.h"
+#include "convert.h"
+#include "trace.h"
+#include "trace2.h"
+#include "string-list.h"
+#include "pack-revindex.h"
+#include "hash.h"
+#include "path.h"
+#include "sha1-array.h"
+#include "repository.h"
+#include "mem-pool.h"
+
+#include <zlib.h>
+typedef struct git_zstream {
+	z_stream z;
+	unsigned long avail_in;
+	unsigned long avail_out;
+	unsigned long total_in;
+	unsigned long total_out;
+	unsigned char *next_in;
+	unsigned char *next_out;
+} git_zstream;
+
+void git_inflate_init(git_zstream *);
+void git_inflate_init_gzip_only(git_zstream *);
+void git_inflate_end(git_zstream *);
+int git_inflate(git_zstream *, int flush);
+
+void git_deflate_init(git_zstream *, int level);
+void git_deflate_init_gzip(git_zstream *, int level);
+void git_deflate_init_raw(git_zstream *, int level);
+void git_deflate_end(git_zstream *);
+int git_deflate_abort(git_zstream *);
+int git_deflate_end_gently(git_zstream *);
+int git_deflate(git_zstream *, int flush);
+unsigned long git_deflate_bound(git_zstream *, unsigned long);
+
+#if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
+#define DTYPE(de)	((de)->d_type)
+#else
+#undef DT_UNKNOWN
+#undef DT_DIR
+#undef DT_REG
+#undef DT_LNK
+#define DT_UNKNOWN	0
+#define DT_DIR		1
+#define DT_REG		2
+#define DT_LNK		3
+#define DTYPE(de)	DT_UNKNOWN
+#endif
+
+/* unknown mode (impossible combination S_IFIFO|S_IFCHR) */
+#define S_IFINVALID     0030000
+
+/*
+ * A "directory link" is a link to another git directory.
+ *
+ * The value 0160000 is not normally a valid mode, and
+ * also just happens to be S_IFDIR + S_IFLNK
+ */
+#define S_IFGITLINK	0160000
+#define S_ISGITLINK(m)	(((m) & S_IFMT) == S_IFGITLINK)
+
+/*
+ * Some mode bits are also used internally for computations.
+ *
+ * They *must* not overlap with any valid modes, and they *must* not be emitted
+ * to outside world - i.e. appear on disk or network. In other words, it's just
+ * temporary fields, which we internally use, but they have to stay in-house.
+ *
+ * ( such approach is valid, as standard S_IF* fits into 16 bits, and in Git
+ *   codebase mode is `unsigned int` which is assumed to be at least 32 bits )
+ */
+
+/* used internally in tree-diff */
+#define S_DIFFTREE_IFXMIN_NEQ	0x80000000
+
+
+/*
+ * Intensive research over the course of many years has shown that
+ * port 9418 is totally unused by anything else. Or
+ *
+ *	Your search - "port 9418" - did not match any documents.
+ *
+ * as www.google.com puts it.
+ *
+ * This port has been properly assigned for git use by IANA:
+ * git (Assigned-9418) [I06-050728-0001].
+ *
+ *	git  9418/tcp   git pack transfer service
+ *	git  9418/udp   git pack transfer service
+ *
+ * with Linus Torvalds <torvalds@osdl.org> as the point of
+ * contact. September 2005.
+ *
+ * See http://www.iana.org/assignments/port-numbers
+ */
+#define DEFAULT_GIT_PORT 9418
+
+/*
+ * Basic data structures for the directory cache
+ */
+
+#define CACHE_SIGNATURE 0x44495243	/* "DIRC" */
+struct cache_header {
+	uint32_t hdr_signature;
+	uint32_t hdr_version;
+	uint32_t hdr_entries;
+};
+
+#define INDEX_FORMAT_LB 2
+#define INDEX_FORMAT_UB 4
+
+/*
+ * The "cache_time" is just the low 32 bits of the
+ * time. It doesn't matter if it overflows - we only
+ * check it for equality in the 32 bits we save.
+ */
+struct cache_time {
+	uint32_t sec;
+	uint32_t nsec;
+};
+
+struct stat_data {
+	struct cache_time sd_ctime;
+	struct cache_time sd_mtime;
+	unsigned int sd_dev;
+	unsigned int sd_ino;
+	unsigned int sd_uid;
+	unsigned int sd_gid;
+	unsigned int sd_size;
+};
+
+struct cache_entry {
+	struct hashmap_entry ent;
+	struct stat_data ce_stat_data;
+	unsigned int ce_mode;
+	unsigned int ce_flags;
+	unsigned int mem_pool_allocated;
+	unsigned int ce_namelen;
+	unsigned int index;	/* for link extension */
+	struct object_id oid;
+	char name[FLEX_ARRAY]; /* more */
+};
+
+#define CE_STAGEMASK (0x3000)
+#define CE_EXTENDED  (0x4000)
+#define CE_VALID     (0x8000)
+#define CE_STAGESHIFT 12
+
+/*
+ * Range 0xFFFF0FFF in ce_flags is divided into
+ * two parts: in-memory flags and on-disk ones.
+ * Flags in CE_EXTENDED_FLAGS will get saved on-disk
+ * if you want to save a new flag, add it in
+ * CE_EXTENDED_FLAGS
+ *
+ * In-memory only flags
+ */
+#define CE_UPDATE            (1 << 16)
+#define CE_REMOVE            (1 << 17)
+#define CE_UPTODATE          (1 << 18)
+#define CE_ADDED             (1 << 19)
+
+#define CE_HASHED            (1 << 20)
+#define CE_FSMONITOR_VALID   (1 << 21)
+#define CE_WT_REMOVE         (1 << 22) /* remove in work directory */
+#define CE_CONFLICTED        (1 << 23)
+
+#define CE_UNPACKED          (1 << 24)
+#define CE_NEW_SKIP_WORKTREE (1 << 25)
+
+/* used to temporarily mark paths matched by pathspecs */
+#define CE_MATCHED           (1 << 26)
+
+#define CE_UPDATE_IN_BASE    (1 << 27)
+#define CE_STRIP_NAME        (1 << 28)
+
+/*
+ * Extended on-disk flags
+ */
+#define CE_INTENT_TO_ADD     (1 << 29)
+#define CE_SKIP_WORKTREE     (1 << 30)
+/* CE_EXTENDED2 is for future extension */
+#define CE_EXTENDED2         (1U << 31)
+
+#define CE_EXTENDED_FLAGS (CE_INTENT_TO_ADD | CE_SKIP_WORKTREE)
+
+/*
+ * Safeguard to avoid saving wrong flags:
+ *  - CE_EXTENDED2 won't get saved until its semantic is known
+ *  - Bits in 0x0000FFFF have been saved in ce_flags already
+ *  - Bits in 0x003F0000 are currently in-memory flags
+ */
+#if CE_EXTENDED_FLAGS & 0x803FFFFF
+#error "CE_EXTENDED_FLAGS out of range"
+#endif
+
+/* Forward structure decls */
+struct pathspec;
+struct child_process;
+struct tree;
+
+/*
+ * Copy the sha1 and stat state of a cache entry from one to
+ * another. But we never change the name, or the hash state!
+ */
+static inline void copy_cache_entry(struct cache_entry *dst,
+				    const struct cache_entry *src)
+{
+	unsigned int state = dst->ce_flags & CE_HASHED;
+	int mem_pool_allocated = dst->mem_pool_allocated;
+
+	/* Don't copy hash chain and name */
+	memcpy(&dst->ce_stat_data, &src->ce_stat_data,
+			offsetof(struct cache_entry, name) -
+			offsetof(struct cache_entry, ce_stat_data));
+
+	/* Restore the hash state */
+	dst->ce_flags = (dst->ce_flags & ~CE_HASHED) | state;
+
+	/* Restore the mem_pool_allocated flag */
+	dst->mem_pool_allocated = mem_pool_allocated;
+}
+
+static inline unsigned create_ce_flags(unsigned stage)
+{
+	return (stage << CE_STAGESHIFT);
+}
+
+#define ce_namelen(ce) ((ce)->ce_namelen)
+#define ce_size(ce) cache_entry_size(ce_namelen(ce))
+#define ce_stage(ce) ((CE_STAGEMASK & (ce)->ce_flags) >> CE_STAGESHIFT)
+#define ce_uptodate(ce) ((ce)->ce_flags & CE_UPTODATE)
+#define ce_skip_worktree(ce) ((ce)->ce_flags & CE_SKIP_WORKTREE)
+#define ce_mark_uptodate(ce) ((ce)->ce_flags |= CE_UPTODATE)
+#define ce_intent_to_add(ce) ((ce)->ce_flags & CE_INTENT_TO_ADD)
+
+#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
+static inline unsigned int create_ce_mode(unsigned int mode)
+{
+	if (S_ISLNK(mode))
+		return S_IFLNK;
+	if (S_ISDIR(mode) || S_ISGITLINK(mode))
+		return S_IFGITLINK;
+	return S_IFREG | ce_permissions(mode);
+}
+static inline unsigned int ce_mode_from_stat(const struct cache_entry *ce,
+					     unsigned int mode)
+{
+	extern int trust_executable_bit, has_symlinks;
+	if (!has_symlinks && S_ISREG(mode) &&
+	    ce && S_ISLNK(ce->ce_mode))
+		return ce->ce_mode;
+	if (!trust_executable_bit && S_ISREG(mode)) {
+		if (ce && S_ISREG(ce->ce_mode))
+			return ce->ce_mode;
+		return create_ce_mode(0666);
+	}
+	return create_ce_mode(mode);
+}
+static inline int ce_to_dtype(const struct cache_entry *ce)
+{
+	unsigned ce_mode = ntohl(ce->ce_mode);
+	if (S_ISREG(ce_mode))
+		return DT_REG;
+	else if (S_ISDIR(ce_mode) || S_ISGITLINK(ce_mode))
+		return DT_DIR;
+	else if (S_ISLNK(ce_mode))
+		return DT_LNK;
+	else
+		return DT_UNKNOWN;
+}
+static inline unsigned int canon_mode(unsigned int mode)
+{
+	if (S_ISREG(mode))
+		return S_IFREG | ce_permissions(mode);
+	if (S_ISLNK(mode))
+		return S_IFLNK;
+	if (S_ISDIR(mode))
+		return S_IFDIR;
+	return S_IFGITLINK;
+}
+
+#define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)
+
+#define SOMETHING_CHANGED	(1 << 0) /* unclassified changes go here */
+#define CE_ENTRY_CHANGED	(1 << 1)
+#define CE_ENTRY_REMOVED	(1 << 2)
+#define CE_ENTRY_ADDED		(1 << 3)
+#define RESOLVE_UNDO_CHANGED	(1 << 4)
+#define CACHE_TREE_CHANGED	(1 << 5)
+#define SPLIT_INDEX_ORDERED	(1 << 6)
+#define UNTRACKED_CHANGED	(1 << 7)
+#define FSMONITOR_CHANGED	(1 << 8)
+
+struct split_index;
+struct untracked_cache;
+
+struct index_state {
+	struct cache_entry **cache;
+	unsigned int version;
+	unsigned int cache_nr, cache_alloc, cache_changed;
+	struct string_list *resolve_undo;
+	struct cache_tree *cache_tree;
+	struct split_index *split_index;
+	struct cache_time timestamp;
+	unsigned name_hash_initialized : 1,
+		 initialized : 1,
+		 drop_cache_tree : 1,
+		 updated_workdir : 1,
+		 updated_skipworktree : 1,
+		 fsmonitor_has_run_once : 1;
+	struct hashmap name_hash;
+	struct hashmap dir_hash;
+	struct object_id oid;
+	struct untracked_cache *untracked;
+	uint64_t fsmonitor_last_update;
+	struct ewah_bitmap *fsmonitor_dirty;
+	struct mem_pool *ce_mem_pool;
+};
+
+/* Name hashing */
+int test_lazy_init_name_hash(struct index_state *istate, int try_threaded);
+void add_name_hash(struct index_state *istate, struct cache_entry *ce);
+void remove_name_hash(struct index_state *istate, struct cache_entry *ce);
+void free_name_hash(struct index_state *istate);
+
+
+/* Cache entry creation and cleanup */
+
+/*
+ * Create cache_entry intended for use in the specified index. Caller
+ * is responsible for discarding the cache_entry with
+ * `discard_cache_entry`.
+ */
+struct cache_entry *make_cache_entry(struct index_state *istate,
+				     unsigned int mode,
+				     const struct object_id *oid,
+				     const char *path,
+				     int stage,
+				     unsigned int refresh_options);
+
+struct cache_entry *make_empty_cache_entry(struct index_state *istate,
+					   size_t name_len);
+
+/*
+ * Create a cache_entry that is not intended to be added to an index.
+ * Caller is responsible for discarding the cache_entry
+ * with `discard_cache_entry`.
+ */
+struct cache_entry *make_transient_cache_entry(unsigned int mode,
+					       const struct object_id *oid,
+					       const char *path,
+					       int stage);
+
+struct cache_entry *make_empty_transient_cache_entry(size_t name_len);
+
+/*
+ * Discard cache entry.
+ */
+void discard_cache_entry(struct cache_entry *ce);
+
+/*
+ * Check configuration if we should perform extra validation on cache
+ * entries.
+ */
+int should_validate_cache_entries(void);
+
+/*
+ * Duplicate a cache_entry. Allocate memory for the new entry from a
+ * memory_pool. Takes into account cache_entry fields that are meant
+ * for managing the underlying memory allocation of the cache_entry.
+ */
+struct cache_entry *dup_cache_entry(const struct cache_entry *ce, struct index_state *istate);
+
+/*
+ * Validate the cache entries in the index.  This is an internal
+ * consistency check that the cache_entry structs are allocated from
+ * the expected memory pool.
+ */
+void validate_cache_entries(const struct index_state *istate);
+
+#ifdef USE_THE_INDEX_COMPATIBILITY_MACROS
+extern struct index_state the_index;
+
+#define active_cache (the_index.cache)
+#define active_nr (the_index.cache_nr)
+#define active_alloc (the_index.cache_alloc)
+#define active_cache_changed (the_index.cache_changed)
+#define active_cache_tree (the_index.cache_tree)
+
+#define read_cache() repo_read_index(the_repository)
+#define read_cache_from(path) read_index_from(&the_index, (path), (get_git_dir()))
+#define read_cache_preload(pathspec) repo_read_index_preload(the_repository, (pathspec), 0)
+#define is_cache_unborn() is_index_unborn(&the_index)
+#define read_cache_unmerged() repo_read_index_unmerged(the_repository)
+#define discard_cache() discard_index(&the_index)
+#define unmerged_cache() unmerged_index(&the_index)
+#define cache_name_pos(name, namelen) index_name_pos(&the_index,(name),(namelen))
+#define add_cache_entry(ce, option) add_index_entry(&the_index, (ce), (option))
+#define rename_cache_entry_at(pos, new_name) rename_index_entry_at(&the_index, (pos), (new_name))
+#define remove_cache_entry_at(pos) remove_index_entry_at(&the_index, (pos))
+#define remove_file_from_cache(path) remove_file_from_index(&the_index, (path))
+#define add_to_cache(path, st, flags) add_to_index(&the_index, (path), (st), (flags))
+#define add_file_to_cache(path, flags) add_file_to_index(&the_index, (path), (flags))
+#define chmod_cache_entry(ce, flip) chmod_index_entry(&the_index, (ce), (flip))
+#define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL, NULL)
+#define ce_match_stat(ce, st, options) ie_match_stat(&the_index, (ce), (st), (options))
+#define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options))
+#define cache_dir_exists(name, namelen) index_dir_exists(&the_index, (name), (namelen))
+#define cache_file_exists(name, namelen, igncase) index_file_exists(&the_index, (name), (namelen), (igncase))
+#define cache_name_is_other(name, namelen) index_name_is_other(&the_index, (name), (namelen))
+#define resolve_undo_clear() resolve_undo_clear_index(&the_index)
+#define unmerge_cache_entry_at(at) unmerge_index_entry_at(&the_index, at)
+#define unmerge_cache(pathspec) unmerge_index(&the_index, pathspec)
+#define read_blob_data_from_cache(path, sz) read_blob_data_from_index(&the_index, (path), (sz))
+#define hold_locked_index(lock_file, flags) repo_hold_locked_index(the_repository, (lock_file), (flags))
+#endif
+
+#define TYPE_BITS 3
+
+/*
+ * Values in this enum (except those outside the 3 bit range) are part
+ * of pack file format. See Documentation/technical/pack-format.txt
+ * for more information.
+ */
+enum object_type {
+	OBJ_BAD = -1,
+	OBJ_NONE = 0,
+	OBJ_COMMIT = 1,
+	OBJ_TREE = 2,
+	OBJ_BLOB = 3,
+	OBJ_TAG = 4,
+	/* 5 for future expansion */
+	OBJ_OFS_DELTA = 6,
+	OBJ_REF_DELTA = 7,
+	OBJ_ANY,
+	OBJ_MAX
+};
+
+static inline enum object_type object_type(unsigned int mode)
+{
+	return S_ISDIR(mode) ? OBJ_TREE :
+		S_ISGITLINK(mode) ? OBJ_COMMIT :
+		OBJ_BLOB;
+}
+
+/* Double-check local_repo_env below if you add to this list. */
+#define GIT_DIR_ENVIRONMENT "GIT_DIR"
+#define GIT_COMMON_DIR_ENVIRONMENT "GIT_COMMON_DIR"
+#define GIT_NAMESPACE_ENVIRONMENT "GIT_NAMESPACE"
+#define GIT_WORK_TREE_ENVIRONMENT "GIT_WORK_TREE"
+#define GIT_PREFIX_ENVIRONMENT "GIT_PREFIX"
+#define GIT_SUPER_PREFIX_ENVIRONMENT "GIT_INTERNAL_SUPER_PREFIX"
+#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
+#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
+#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
+#define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
+#define GIT_SHALLOW_FILE_ENVIRONMENT "GIT_SHALLOW_FILE"
+#define TEMPLATE_DIR_ENVIRONMENT "GIT_TEMPLATE_DIR"
+#define CONFIG_ENVIRONMENT "GIT_CONFIG"
+#define CONFIG_DATA_ENVIRONMENT "GIT_CONFIG_PARAMETERS"
+#define EXEC_PATH_ENVIRONMENT "GIT_EXEC_PATH"
+#define CEILING_DIRECTORIES_ENVIRONMENT "GIT_CEILING_DIRECTORIES"
+#define NO_REPLACE_OBJECTS_ENVIRONMENT "GIT_NO_REPLACE_OBJECTS"
+#define GIT_REPLACE_REF_BASE_ENVIRONMENT "GIT_REPLACE_REF_BASE"
+#define GITATTRIBUTES_FILE ".gitattributes"
+#define INFOATTRIBUTES_FILE "info/attributes"
+#define ATTRIBUTE_MACRO_PREFIX "[attr]"
+#define GITMODULES_FILE ".gitmodules"
+#define GITMODULES_INDEX ":.gitmodules"
+#define GITMODULES_HEAD "HEAD:.gitmodules"
+#define GIT_NOTES_REF_ENVIRONMENT "GIT_NOTES_REF"
+#define GIT_NOTES_DEFAULT_REF "refs/notes/commits"
+#define GIT_NOTES_DISPLAY_REF_ENVIRONMENT "GIT_NOTES_DISPLAY_REF"
+#define GIT_NOTES_REWRITE_REF_ENVIRONMENT "GIT_NOTES_REWRITE_REF"
+#define GIT_NOTES_REWRITE_MODE_ENVIRONMENT "GIT_NOTES_REWRITE_MODE"
+#define GIT_LITERAL_PATHSPECS_ENVIRONMENT "GIT_LITERAL_PATHSPECS"
+#define GIT_GLOB_PATHSPECS_ENVIRONMENT "GIT_GLOB_PATHSPECS"
+#define GIT_NOGLOB_PATHSPECS_ENVIRONMENT "GIT_NOGLOB_PATHSPECS"
+#define GIT_ICASE_PATHSPECS_ENVIRONMENT "GIT_ICASE_PATHSPECS"
+#define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
+#define GIT_OPTIONAL_LOCKS_ENVIRONMENT "GIT_OPTIONAL_LOCKS"
+#define GIT_TEXT_DOMAIN_DIR_ENVIRONMENT "GIT_TEXTDOMAINDIR"
+
+/*
+ * Environment variable used in handshaking the wire protocol.
+ * Contains a colon ':' separated list of keys with optional values
+ * 'key[=value]'.  Presence of unknown keys and values must be
+ * ignored.
+ */
+#define GIT_PROTOCOL_ENVIRONMENT "GIT_PROTOCOL"
+/* HTTP header used to handshake the wire protocol */
+#define GIT_PROTOCOL_HEADER "Git-Protocol"
+
+/*
+ * This environment variable is expected to contain a boolean indicating
+ * whether we should or should not treat:
+ *
+ *   GIT_DIR=foo.git git ...
+ *
+ * as if GIT_WORK_TREE=. was given. It's not expected that users will make use
+ * of this, but we use it internally to communicate to sub-processes that we
+ * are in a bare repo. If not set, defaults to true.
+ */
+#define GIT_IMPLICIT_WORK_TREE_ENVIRONMENT "GIT_IMPLICIT_WORK_TREE"
+
+/*
+ * Repository-local GIT_* environment variables; these will be cleared
+ * when git spawns a sub-process that runs inside another repository.
+ * The array is NULL-terminated, which makes it easy to pass in the "env"
+ * parameter of a run-command invocation, or to do a simple walk.
+ */
+extern const char * const local_repo_env[];
+
+void setup_git_env(const char *git_dir);
+
+/*
+ * Returns true iff we have a configured git repository (either via
+ * setup_git_directory, or in the environment via $GIT_DIR).
+ */
+int have_git_dir(void);
+
+extern int is_bare_repository_cfg;
+int is_bare_repository(void);
+int is_inside_git_dir(void);
+extern char *git_work_tree_cfg;
+int is_inside_work_tree(void);
+const char *get_git_dir(void);
+const char *get_git_common_dir(void);
+char *get_object_directory(void);
+char *get_index_file(void);
+char *get_graft_file(struct repository *r);
+void set_git_dir(const char *path);
+int get_common_dir_noenv(struct strbuf *sb, const char *gitdir);
+int get_common_dir(struct strbuf *sb, const char *gitdir);
+const char *get_git_namespace(void);
+const char *strip_namespace(const char *namespaced_ref);
+const char *get_super_prefix(void);
+const char *get_git_work_tree(void);
+
+/*
+ * Return true if the given path is a git directory; note that this _just_
+ * looks at the directory itself. If you want to know whether "foo/.git"
+ * is a repository, you must feed that path, not just "foo".
+ */
+int is_git_directory(const char *path);
+
+/*
+ * Return 1 if the given path is the root of a git repository or
+ * submodule, else 0. Will not return 1 for bare repositories with the
+ * exception of creating a bare repository in "foo/.git" and calling
+ * is_git_repository("foo").
+ *
+ * If we run into read errors, we err on the side of saying "yes, it is",
+ * as we usually consider sub-repos precious, and would prefer to err on the
+ * side of not disrupting or deleting them.
+ */
+int is_nonbare_repository_dir(struct strbuf *path);
+
+#define READ_GITFILE_ERR_STAT_FAILED 1
+#define READ_GITFILE_ERR_NOT_A_FILE 2
+#define READ_GITFILE_ERR_OPEN_FAILED 3
+#define READ_GITFILE_ERR_READ_FAILED 4
+#define READ_GITFILE_ERR_INVALID_FORMAT 5
+#define READ_GITFILE_ERR_NO_PATH 6
+#define READ_GITFILE_ERR_NOT_A_REPO 7
+#define READ_GITFILE_ERR_TOO_LARGE 8
+void read_gitfile_error_die(int error_code, const char *path, const char *dir);
+const char *read_gitfile_gently(const char *path, int *return_error_code);
+#define read_gitfile(path) read_gitfile_gently((path), NULL)
+const char *resolve_gitdir_gently(const char *suspect, int *return_error_code);
+#define resolve_gitdir(path) resolve_gitdir_gently((path), NULL)
+
+void set_git_work_tree(const char *tree);
+
+#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
+
+void setup_work_tree(void);
+/*
+ * Find the commondir and gitdir of the repository that contains the current
+ * working directory, without changing the working directory or other global
+ * state. The result is appended to commondir and gitdir.  If the discovered
+ * gitdir does not correspond to a worktree, then 'commondir' and 'gitdir' will
+ * both have the same result appended to the buffer.  The return value is
+ * either 0 upon success and non-zero if no repository was found.
+ */
+int discover_git_directory(struct strbuf *commondir,
+			   struct strbuf *gitdir);
+const char *setup_git_directory_gently(int *);
+const char *setup_git_directory(void);
+char *prefix_path(const char *prefix, int len, const char *path);
+char *prefix_path_gently(const char *prefix, int len, int *remaining, const char *path);
+
+/*
+ * Concatenate "prefix" (if len is non-zero) and "path", with no
+ * connecting characters (so "prefix" should end with a "/").
+ * Unlike prefix_path, this should be used if the named file does
+ * not have to interact with index entry; i.e. name of a random file
+ * on the filesystem.
+ *
+ * The return value is always a newly allocated string (even if the
+ * prefix was empty).
+ */
+char *prefix_filename(const char *prefix, const char *path);
+
+int check_filename(const char *prefix, const char *name);
+void verify_filename(const char *prefix,
+		     const char *name,
+		     int diagnose_misspelt_rev);
+void verify_non_filename(const char *prefix, const char *name);
+int path_inside_repo(const char *prefix, const char *path);
+
+#define INIT_DB_QUIET 0x0001
+#define INIT_DB_EXIST_OK 0x0002
+
+int init_db(const char *git_dir, const char *real_git_dir,
+	    const char *template_dir, unsigned int flags);
+
+void sanitize_stdfds(void);
+int daemonize(void);
+
+#define alloc_nr(x) (((x)+16)*3/2)
+
+/*
+ * Realloc the buffer pointed at by variable 'x' so that it can hold
+ * at least 'nr' entries; the number of entries currently allocated
+ * is 'alloc', using the standard growing factor alloc_nr() macro.
+ *
+ * DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'.
+ */
+#define ALLOC_GROW(x, nr, alloc) \
+	do { \
+		if ((nr) > alloc) { \
+			if (alloc_nr(alloc) < (nr)) \
+				alloc = (nr); \
+			else \
+				alloc = alloc_nr(alloc); \
+			REALLOC_ARRAY(x, alloc); \
+		} \
+	} while (0)
+
+/* Initialize and use the cache information */
+struct lock_file;
+void preload_index(struct index_state *index,
+		   const struct pathspec *pathspec,
+		   unsigned int refresh_flags);
+int do_read_index(struct index_state *istate, const char *path,
+		  int must_exist); /* for testting only! */
+int read_index_from(struct index_state *, const char *path,
+		    const char *gitdir);
+int is_index_unborn(struct index_state *);
+
+/* For use with `write_locked_index()`. */
+#define COMMIT_LOCK		(1 << 0)
+#define SKIP_IF_UNCHANGED	(1 << 1)
+
+/*
+ * Write the index while holding an already-taken lock. Close the lock,
+ * and if `COMMIT_LOCK` is given, commit it.
+ *
+ * Unless a split index is in use, write the index into the lockfile.
+ *
+ * With a split index, write the shared index to a temporary file,
+ * adjust its permissions and rename it into place, then write the
+ * split index to the lockfile. If the temporary file for the shared
+ * index cannot be created, fall back to the behavior described in
+ * the previous paragraph.
+ *
+ * With `COMMIT_LOCK`, the lock is always committed or rolled back.
+ * Without it, the lock is closed, but neither committed nor rolled
+ * back.
+ *
+ * If `SKIP_IF_UNCHANGED` is given and the index is unchanged, nothing
+ * is written (and the lock is rolled back if `COMMIT_LOCK` is given).
+ */
+int write_locked_index(struct index_state *, struct lock_file *lock, unsigned flags);
+
+int discard_index(struct index_state *);
+void move_index_extensions(struct index_state *dst, struct index_state *src);
+int unmerged_index(const struct index_state *);
+
+/**
+ * Returns 1 if istate differs from tree, 0 otherwise.  If tree is NULL,
+ * compares istate to HEAD.  If tree is NULL and on an unborn branch,
+ * returns 1 if there are entries in istate, 0 otherwise.  If an strbuf is
+ * provided, the space-separated list of files that differ will be appended
+ * to it.
+ */
+int repo_index_has_changes(struct repository *repo,
+			   struct tree *tree,
+			   struct strbuf *sb);
+
+int verify_path(const char *path, unsigned mode);
+int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
+int index_dir_exists(struct index_state *istate, const char *name, int namelen);
+void adjust_dirname_case(struct index_state *istate, char *name);
+struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int igncase);
+
+/*
+ * Searches for an entry defined by name and namelen in the given index.
+ * If the return value is positive (including 0) it is the position of an
+ * exact match. If the return value is negative, the negated value minus 1
+ * is the position where the entry would be inserted.
+ * Example: The current index consists of these files and its stages:
+ *
+ *   b#0, d#0, f#1, f#3
+ *
+ * index_name_pos(&index, "a", 1) -> -1
+ * index_name_pos(&index, "b", 1) ->  0
+ * index_name_pos(&index, "c", 1) -> -2
+ * index_name_pos(&index, "d", 1) ->  1
+ * index_name_pos(&index, "e", 1) -> -3
+ * index_name_pos(&index, "f", 1) -> -3
+ * index_name_pos(&index, "g", 1) -> -5
+ */
+int index_name_pos(const struct index_state *, const char *name, int namelen);
+
+#define ADD_CACHE_OK_TO_ADD 1		/* Ok to add */
+#define ADD_CACHE_OK_TO_REPLACE 2	/* Ok to replace file/directory */
+#define ADD_CACHE_SKIP_DFCHECK 4	/* Ok to skip DF conflict checks */
+#define ADD_CACHE_JUST_APPEND 8		/* Append only; tree.c::read_tree() */
+#define ADD_CACHE_NEW_ONLY 16		/* Do not replace existing ones */
+#define ADD_CACHE_KEEP_CACHE_TREE 32	/* Do not invalidate cache-tree */
+#define ADD_CACHE_RENORMALIZE 64        /* Pass along HASH_RENORMALIZE */
+int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
+void rename_index_entry_at(struct index_state *, int pos, const char *new_name);
+
+/* Remove entry, return true if there are more entries to go. */
+int remove_index_entry_at(struct index_state *, int pos);
+
+void remove_marked_cache_entries(struct index_state *istate, int invalidate);
+int remove_file_from_index(struct index_state *, const char *path);
+#define ADD_CACHE_VERBOSE 1
+#define ADD_CACHE_PRETEND 2
+#define ADD_CACHE_IGNORE_ERRORS	4
+#define ADD_CACHE_IGNORE_REMOVAL 8
+#define ADD_CACHE_INTENT 16
+/*
+ * These two are used to add the contents of the file at path
+ * to the index, marking the working tree up-to-date by storing
+ * the cached stat info in the resulting cache entry.  A caller
+ * that has already run lstat(2) on the path can call
+ * add_to_index(), and all others can call add_file_to_index();
+ * the latter will do necessary lstat(2) internally before
+ * calling the former.
+ */
+int add_to_index(struct index_state *, const char *path, struct stat *, int flags);
+int add_file_to_index(struct index_state *, const char *path, int flags);
+
+int chmod_index_entry(struct index_state *, struct cache_entry *ce, char flip);
+int ce_same_name(const struct cache_entry *a, const struct cache_entry *b);
+void set_object_name_for_intent_to_add_entry(struct cache_entry *ce);
+int index_name_is_other(const struct index_state *, const char *, int);
+void *read_blob_data_from_index(const struct index_state *, const char *, unsigned long *);
+
+/* do stat comparison even if CE_VALID is true */
+#define CE_MATCH_IGNORE_VALID		01
+/* do not check the contents but report dirty on racily-clean entries */
+#define CE_MATCH_RACY_IS_DIRTY		02
+/* do stat comparison even if CE_SKIP_WORKTREE is true */
+#define CE_MATCH_IGNORE_SKIP_WORKTREE	04
+/* ignore non-existent files during stat update  */
+#define CE_MATCH_IGNORE_MISSING		0x08
+/* enable stat refresh */
+#define CE_MATCH_REFRESH		0x10
+/* don't refresh_fsmonitor state or do stat comparison even if CE_FSMONITOR_VALID is true */
+#define CE_MATCH_IGNORE_FSMONITOR 0X20
+int is_racy_timestamp(const struct index_state *istate,
+		      const struct cache_entry *ce);
+int ie_match_stat(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
+int ie_modified(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
+
+#define HASH_WRITE_OBJECT 1
+#define HASH_FORMAT_CHECK 2
+#define HASH_RENORMALIZE  4
+int index_fd(struct index_state *istate, struct object_id *oid, int fd, struct stat *st, enum object_type type, const char *path, unsigned flags);
+int index_path(struct index_state *istate, struct object_id *oid, const char *path, struct stat *st, unsigned flags);
+
+/*
+ * Record to sd the data from st that we use to check whether a file
+ * might have changed.
+ */
+void fill_stat_data(struct stat_data *sd, struct stat *st);
+
+/*
+ * Return 0 if st is consistent with a file not having been changed
+ * since sd was filled.  If there are differences, return a
+ * combination of MTIME_CHANGED, CTIME_CHANGED, OWNER_CHANGED,
+ * INODE_CHANGED, and DATA_CHANGED.
+ */
+int match_stat_data(const struct stat_data *sd, struct stat *st);
+int match_stat_data_racy(const struct index_state *istate,
+			 const struct stat_data *sd, struct stat *st);
+
+void fill_stat_cache_info(struct index_state *istate, struct cache_entry *ce, struct stat *st);
+
+#define REFRESH_REALLY		0x0001	/* ignore_valid */
+#define REFRESH_UNMERGED	0x0002	/* allow unmerged */
+#define REFRESH_QUIET		0x0004	/* be quiet about it */
+#define REFRESH_IGNORE_MISSING	0x0008	/* ignore non-existent */
+#define REFRESH_IGNORE_SUBMODULES	0x0010	/* ignore submodules */
+#define REFRESH_IN_PORCELAIN	0x0020	/* user friendly output, not "needs update" */
+#define REFRESH_PROGRESS	0x0040  /* show progress bar if stderr is tty */
+int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
+struct cache_entry *refresh_cache_entry(struct index_state *, struct cache_entry *, unsigned int);
+
+void set_alternate_index_output(const char *);
+
+extern int verify_index_checksum;
+extern int verify_ce_order;
+
+/* Environment bits from configuration mechanism */
+extern int trust_executable_bit;
+extern int trust_ctime;
+extern int check_stat;
+extern int quote_path_fully;
+extern int has_symlinks;
+extern int minimum_abbrev, default_abbrev;
+extern int ignore_case;
+extern int assume_unchanged;
+extern int prefer_symlink_refs;
+extern int warn_ambiguous_refs;
+extern int warn_on_object_refname_ambiguity;
+extern const char *apply_default_whitespace;
+extern const char *apply_default_ignorewhitespace;
+extern const char *git_attributes_file;
+extern const char *git_hooks_path;
+extern int zlib_compression_level;
+extern int core_compression_level;
+extern int pack_compression_level;
+extern size_t packed_git_window_size;
+extern size_t packed_git_limit;
+extern size_t delta_base_cache_limit;
+extern unsigned long big_file_threshold;
+extern unsigned long pack_size_limit_cfg;
+
+/*
+ * Accessors for the core.sharedrepository config which lazy-load the value
+ * from the config (if not already set). The "reset" function can be
+ * used to unset "set" or cached value, meaning that the value will be loaded
+ * fresh from the config file on the next call to get_shared_repository().
+ */
+void set_shared_repository(int value);
+int get_shared_repository(void);
+void reset_shared_repository(void);
+
+/*
+ * Do replace refs need to be checked this run?  This variable is
+ * initialized to true unless --no-replace-object is used or
+ * $GIT_NO_REPLACE_OBJECTS is set, but is set to false by some
+ * commands that do not want replace references to be active.
+ */
+extern int read_replace_refs;
+extern char *git_replace_ref_base;
+
+extern int fsync_object_files;
+extern int core_preload_index;
+extern int core_apply_sparse_checkout;
+extern int precomposed_unicode;
+extern int protect_hfs;
+extern int protect_ntfs;
+extern const char *core_fsmonitor;
+
+/*
+ * Include broken refs in all ref iterations, which will
+ * generally choke dangerous operations rather than letting
+ * them silently proceed without taking the broken ref into
+ * account.
+ */
+extern int ref_paranoia;
+
+/*
+ * Returns the boolean value of $GIT_OPTIONAL_LOCKS (or the default value).
+ */
+int use_optional_locks(void);
+
+/*
+ * The character that begins a commented line in user-editable file
+ * that is subject to stripspace.
+ */
+extern char comment_line_char;
+extern int auto_comment_line_char;
+
+enum log_refs_config {
+	LOG_REFS_UNSET = -1,
+	LOG_REFS_NONE = 0,
+	LOG_REFS_NORMAL,
+	LOG_REFS_ALWAYS
+};
+extern enum log_refs_config log_all_ref_updates;
+
+enum rebase_setup_type {
+	AUTOREBASE_NEVER = 0,
+	AUTOREBASE_LOCAL,
+	AUTOREBASE_REMOTE,
+	AUTOREBASE_ALWAYS
+};
+
+enum push_default_type {
+	PUSH_DEFAULT_NOTHING = 0,
+	PUSH_DEFAULT_MATCHING,
+	PUSH_DEFAULT_SIMPLE,
+	PUSH_DEFAULT_UPSTREAM,
+	PUSH_DEFAULT_CURRENT,
+	PUSH_DEFAULT_UNSPECIFIED
+};
+
+extern enum rebase_setup_type autorebase;
+extern enum push_default_type push_default;
+
+enum object_creation_mode {
+	OBJECT_CREATION_USES_HARDLINKS = 0,
+	OBJECT_CREATION_USES_RENAMES = 1
+};
+
+extern enum object_creation_mode object_creation_mode;
+
+extern char *notes_ref_name;
+
+extern int grafts_replace_parents;
+
+/*
+ * GIT_REPO_VERSION is the version we write by default. The
+ * _READ variant is the highest number we know how to
+ * handle.
+ */
+#define GIT_REPO_VERSION 0
+#define GIT_REPO_VERSION_READ 1
+extern int repository_format_precious_objects;
+extern char *repository_format_partial_clone;
+extern const char *core_partial_clone_filter_default;
+extern int repository_format_worktree_config;
+
+/*
+ * You _have_ to initialize a `struct repository_format` using
+ * `= REPOSITORY_FORMAT_INIT` before calling `read_repository_format()`.
+ */
+struct repository_format {
+	int version;
+	int precious_objects;
+	char *partial_clone; /* value of extensions.partialclone */
+	int worktree_config;
+	int is_bare;
+	int hash_algo;
+	char *work_tree;
+	struct string_list unknown_extensions;
+};
+
+/*
+ * Always use this to initialize a `struct repository_format`
+ * to a well-defined, default state before calling
+ * `read_repository()`.
+ */
+#define REPOSITORY_FORMAT_INIT \
+{ \
+	.version = -1, \
+	.is_bare = -1, \
+	.hash_algo = GIT_HASH_SHA1, \
+	.unknown_extensions = STRING_LIST_INIT_DUP, \
+}
+
+/*
+ * Read the repository format characteristics from the config file "path" into
+ * "format" struct. Returns the numeric version. On error, or if no version is
+ * found in the configuration, -1 is returned, format->version is set to -1,
+ * and all other fields in the struct are set to the default configuration
+ * (REPOSITORY_FORMAT_INIT). Always initialize the struct using
+ * REPOSITORY_FORMAT_INIT before calling this function.
+ */
+int read_repository_format(struct repository_format *format, const char *path);
+
+/*
+ * Free the memory held onto by `format`, but not the struct itself.
+ * (No need to use this after `read_repository_format()` fails.)
+ */
+void clear_repository_format(struct repository_format *format);
+
+/*
+ * Verify that the repository described by repository_format is something we
+ * can read. If it is, return 0. Otherwise, return -1, and "err" will describe
+ * any errors encountered.
+ */
+int verify_repository_format(const struct repository_format *format,
+			     struct strbuf *err);
+
+/*
+ * Check the repository format version in the path found in get_git_dir(),
+ * and die if it is a version we don't understand. Generally one would
+ * set_git_dir() before calling this, and use it only for "are we in a valid
+ * repo?".
+ */
+void check_repository_format(void);
+
+#define MTIME_CHANGED	0x0001
+#define CTIME_CHANGED	0x0002
+#define OWNER_CHANGED	0x0004
+#define MODE_CHANGED    0x0008
+#define INODE_CHANGED   0x0010
+#define DATA_CHANGED    0x0020
+#define TYPE_CHANGED    0x0040
+
+/*
+ * Return an abbreviated sha1 unique within this repository's object database.
+ * The result will be at least `len` characters long, and will be NUL
+ * terminated.
+ *
+ * The non-`_r` version returns a static buffer which remains valid until 4
+ * more calls to find_unique_abbrev are made.
+ *
+ * The `_r` variant writes to a buffer supplied by the caller, which must be at
+ * least `GIT_MAX_HEXSZ + 1` bytes. The return value is the number of bytes
+ * written (excluding the NUL terminator).
+ *
+ * Note that while this version avoids the static buffer, it is not fully
+ * reentrant, as it calls into other non-reentrant git code.
+ */
+const char *repo_find_unique_abbrev(struct repository *r, const struct object_id *oid, int len);
+#define find_unique_abbrev(oid, len) repo_find_unique_abbrev(the_repository, oid, len)
+int repo_find_unique_abbrev_r(struct repository *r, char *hex, const struct object_id *oid, int len);
+#define find_unique_abbrev_r(hex, oid, len) repo_find_unique_abbrev_r(the_repository, hex, oid, len)
+
+extern const unsigned char null_sha1[GIT_MAX_RAWSZ];
+extern const struct object_id null_oid;
+
+static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
+{
+	/*
+	 * Teach the compiler that there are only two possibilities of hash size
+	 * here, so that it can optimize for this case as much as possible.
+	 */
+	if (the_hash_algo->rawsz == GIT_MAX_RAWSZ)
+		return memcmp(sha1, sha2, GIT_MAX_RAWSZ);
+	return memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
+}
+
+static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2)
+{
+	return hashcmp(oid1->hash, oid2->hash);
+}
+
+static inline int hasheq(const unsigned char *sha1, const unsigned char *sha2)
+{
+	/*
+	 * We write this here instead of deferring to hashcmp so that the
+	 * compiler can properly inline it and avoid calling memcmp.
+	 */
+	if (the_hash_algo->rawsz == GIT_MAX_RAWSZ)
+		return !memcmp(sha1, sha2, GIT_MAX_RAWSZ);
+	return !memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
+}
+
+static inline int oideq(const struct object_id *oid1, const struct object_id *oid2)
+{
+	return hasheq(oid1->hash, oid2->hash);
+}
+
+static inline int is_null_sha1(const unsigned char *sha1)
+{
+	return hasheq(sha1, null_sha1);
+}
+
+static inline int is_null_oid(const struct object_id *oid)
+{
+	return hasheq(oid->hash, null_sha1);
+}
+
+static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
+{
+	memcpy(sha_dst, sha_src, the_hash_algo->rawsz);
+}
+
+static inline void oidcpy(struct object_id *dst, const struct object_id *src)
+{
+	memcpy(dst->hash, src->hash, GIT_MAX_RAWSZ);
+}
+
+static inline struct object_id *oiddup(const struct object_id *src)
+{
+	struct object_id *dst = xmalloc(sizeof(struct object_id));
+	oidcpy(dst, src);
+	return dst;
+}
+
+static inline void hashclr(unsigned char *hash)
+{
+	memset(hash, 0, the_hash_algo->rawsz);
+}
+
+static inline void oidclr(struct object_id *oid)
+{
+	memset(oid->hash, 0, GIT_MAX_RAWSZ);
+}
+
+static inline void oidread(struct object_id *oid, const unsigned char *hash)
+{
+	memcpy(oid->hash, hash, the_hash_algo->rawsz);
+}
+
+static inline int is_empty_blob_sha1(const unsigned char *sha1)
+{
+	return hasheq(sha1, the_hash_algo->empty_blob->hash);
+}
+
+static inline int is_empty_blob_oid(const struct object_id *oid)
+{
+	return oideq(oid, the_hash_algo->empty_blob);
+}
+
+static inline int is_empty_tree_sha1(const unsigned char *sha1)
+{
+	return hasheq(sha1, the_hash_algo->empty_tree->hash);
+}
+
+static inline int is_empty_tree_oid(const struct object_id *oid)
+{
+	return oideq(oid, the_hash_algo->empty_tree);
+}
+
+const char *empty_tree_oid_hex(void);
+const char *empty_blob_oid_hex(void);
+
+/* set default permissions by passing mode arguments to open(2) */
+int git_mkstemps_mode(char *pattern, int suffix_len, int mode);
+int git_mkstemp_mode(char *pattern, int mode);
+
+/*
+ * NOTE NOTE NOTE!!
+ *
+ * PERM_UMASK, OLD_PERM_GROUP and OLD_PERM_EVERYBODY enumerations must
+ * not be changed. Old repositories have core.sharedrepository written in
+ * numeric format, and therefore these values are preserved for compatibility
+ * reasons.
+ */
+enum sharedrepo {
+	PERM_UMASK          = 0,
+	OLD_PERM_GROUP      = 1,
+	OLD_PERM_EVERYBODY  = 2,
+	PERM_GROUP          = 0660,
+	PERM_EVERYBODY      = 0664
+};
+int git_config_perm(const char *var, const char *value);
+int adjust_shared_perm(const char *path);
+
+/*
+ * Create the directory containing the named path, using care to be
+ * somewhat safe against races. Return one of the scld_error values to
+ * indicate success/failure. On error, set errno to describe the
+ * problem.
+ *
+ * SCLD_VANISHED indicates that one of the ancestor directories of the
+ * path existed at one point during the function call and then
+ * suddenly vanished, probably because another process pruned the
+ * directory while we were working.  To be robust against this kind of
+ * race, callers might want to try invoking the function again when it
+ * returns SCLD_VANISHED.
+ *
+ * safe_create_leading_directories() temporarily changes path while it
+ * is working but restores it before returning.
+ * safe_create_leading_directories_const() doesn't modify path, even
+ * temporarily.
+ */
+enum scld_error {
+	SCLD_OK = 0,
+	SCLD_FAILED = -1,
+	SCLD_PERMS = -2,
+	SCLD_EXISTS = -3,
+	SCLD_VANISHED = -4
+};
+enum scld_error safe_create_leading_directories(char *path);
+enum scld_error safe_create_leading_directories_const(const char *path);
+
+/*
+ * Callback function for raceproof_create_file(). This function is
+ * expected to do something that makes dirname(path) permanent despite
+ * the fact that other processes might be cleaning up empty
+ * directories at the same time. Usually it will create a file named
+ * path, but alternatively it could create another file in that
+ * directory, or even chdir() into that directory. The function should
+ * return 0 if the action was completed successfully. On error, it
+ * should return a nonzero result and set errno.
+ * raceproof_create_file() treats two errno values specially:
+ *
+ * - ENOENT -- dirname(path) does not exist. In this case,
+ *             raceproof_create_file() tries creating dirname(path)
+ *             (and any parent directories, if necessary) and calls
+ *             the function again.
+ *
+ * - EISDIR -- the file already exists and is a directory. In this
+ *             case, raceproof_create_file() removes the directory if
+ *             it is empty (and recursively any empty directories that
+ *             it contains) and calls the function again.
+ *
+ * Any other errno causes raceproof_create_file() to fail with the
+ * callback's return value and errno.
+ *
+ * Obviously, this function should be OK with being called again if it
+ * fails with ENOENT or EISDIR. In other scenarios it will not be
+ * called again.
+ */
+typedef int create_file_fn(const char *path, void *cb);
+
+/*
+ * Create a file in dirname(path) by calling fn, creating leading
+ * directories if necessary. Retry a few times in case we are racing
+ * with another process that is trying to clean up the directory that
+ * contains path. See the documentation for create_file_fn for more
+ * details.
+ *
+ * Return the value and set the errno that resulted from the most
+ * recent call of fn. fn is always called at least once, and will be
+ * called more than once if it returns ENOENT or EISDIR.
+ */
+int raceproof_create_file(const char *path, create_file_fn fn, void *cb);
+
+int mkdir_in_gitdir(const char *path);
+char *expand_user_path(const char *path, int real_home);
+const char *enter_repo(const char *path, int strict);
+static inline int is_absolute_path(const char *path)
+{
+	return is_dir_sep(path[0]) || has_dos_drive_prefix(path);
+}
+int is_directory(const char *);
+char *strbuf_realpath(struct strbuf *resolved, const char *path,
+		      int die_on_error);
+const char *real_path(const char *path);
+const char *real_path_if_valid(const char *path);
+char *real_pathdup(const char *path, int die_on_error);
+const char *absolute_path(const char *path);
+char *absolute_pathdup(const char *path);
+const char *remove_leading_path(const char *in, const char *prefix);
+const char *relative_path(const char *in, const char *prefix, struct strbuf *sb);
+int normalize_path_copy_len(char *dst, const char *src, int *prefix_len);
+int normalize_path_copy(char *dst, const char *src);
+int longest_ancestor_length(const char *path, struct string_list *prefixes);
+char *strip_path_suffix(const char *path, const char *suffix);
+int daemon_avoid_alias(const char *path);
+
+/*
+ * These functions match their is_hfs_dotgit() counterparts; see utf8.h for
+ * details.
+ */
+int is_ntfs_dotgit(const char *name);
+int is_ntfs_dotgitmodules(const char *name);
+int is_ntfs_dotgitignore(const char *name);
+int is_ntfs_dotgitattributes(const char *name);
+
+/*
+ * Returns true iff "str" could be confused as a command-line option when
+ * passed to a sub-program like "ssh". Note that this has nothing to do with
+ * shell-quoting, which should be handled separately; we're assuming here that
+ * the string makes it verbatim to the sub-program.
+ */
+int looks_like_command_line_option(const char *str);
+
+/**
+ * Return a newly allocated string with the evaluation of
+ * "$XDG_CONFIG_HOME/git/$filename" if $XDG_CONFIG_HOME is non-empty, otherwise
+ * "$HOME/.config/git/$filename". Return NULL upon error.
+ */
+char *xdg_config_home(const char *filename);
+
+/**
+ * Return a newly allocated string with the evaluation of
+ * "$XDG_CACHE_HOME/git/$filename" if $XDG_CACHE_HOME is non-empty, otherwise
+ * "$HOME/.cache/git/$filename". Return NULL upon error.
+ */
+char *xdg_cache_home(const char *filename);
+
+int git_open_cloexec(const char *name, int flags);
+#define git_open(name) git_open_cloexec(name, O_RDONLY)
+int unpack_loose_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
+int parse_loose_header(const char *hdr, unsigned long *sizep);
+
+int check_object_signature(const struct object_id *oid, void *buf, unsigned long size, const char *type);
+
+int finalize_object_file(const char *tmpfile, const char *filename);
+
+/* Helper to check and "touch" a file */
+int check_and_freshen_file(const char *fn, int freshen);
+
+extern const signed char hexval_table[256];
+static inline unsigned int hexval(unsigned char c)
+{
+	return hexval_table[c];
+}
+
+/*
+ * Convert two consecutive hexadecimal digits into a char.  Return a
+ * negative value on error.  Don't run over the end of short strings.
+ */
+static inline int hex2chr(const char *s)
+{
+	unsigned int val = hexval(s[0]);
+	return (val & ~0xf) ? val : (val << 4) | hexval(s[1]);
+}
+
+/* Convert to/from hex/sha1 representation */
+#define MINIMUM_ABBREV minimum_abbrev
+#define DEFAULT_ABBREV default_abbrev
+
+/* used when the code does not know or care what the default abbrev is */
+#define FALLBACK_DEFAULT_ABBREV 7
+
+struct object_context {
+	unsigned short mode;
+	/*
+	 * symlink_path is only used by get_tree_entry_follow_symlinks,
+	 * and only for symlinks that point outside the repository.
+	 */
+	struct strbuf symlink_path;
+	/*
+	 * If GET_OID_RECORD_PATH is set, this will record path (if any)
+	 * found when resolving the name. The caller is responsible for
+	 * releasing the memory.
+	 */
+	char *path;
+};
+
+#define GET_OID_QUIETLY           01
+#define GET_OID_COMMIT            02
+#define GET_OID_COMMITTISH        04
+#define GET_OID_TREE             010
+#define GET_OID_TREEISH          020
+#define GET_OID_BLOB             040
+#define GET_OID_FOLLOW_SYMLINKS 0100
+#define GET_OID_RECORD_PATH     0200
+#define GET_OID_ONLY_TO_DIE    04000
+
+#define GET_OID_DISAMBIGUATORS \
+	(GET_OID_COMMIT | GET_OID_COMMITTISH | \
+	GET_OID_TREE | GET_OID_TREEISH | \
+	GET_OID_BLOB)
+
+enum get_oid_result {
+	FOUND = 0,
+	MISSING_OBJECT = -1, /* The requested object is missing */
+	SHORT_NAME_AMBIGUOUS = -2,
+	/* The following only apply when symlinks are followed */
+	DANGLING_SYMLINK = -4, /*
+				* The initial symlink is there, but
+				* (transitively) points to a missing
+				* in-tree file
+				*/
+	SYMLINK_LOOP = -5,
+	NOT_DIR = -6, /*
+		       * Somewhere along the symlink chain, a path is
+		       * requested which contains a file as a
+		       * non-final element.
+		       */
+};
+
+int repo_get_oid(struct repository *r, const char *str, struct object_id *oid);
+int get_oidf(struct object_id *oid, const char *fmt, ...);
+int repo_get_oid_commit(struct repository *r, const char *str, struct object_id *oid);
+int repo_get_oid_committish(struct repository *r, const char *str, struct object_id *oid);
+int repo_get_oid_tree(struct repository *r, const char *str, struct object_id *oid);
+int repo_get_oid_treeish(struct repository *r, const char *str, struct object_id *oid);
+int repo_get_oid_blob(struct repository *r, const char *str, struct object_id *oid);
+int repo_get_oid_mb(struct repository *r, const char *str, struct object_id *oid);
+void maybe_die_on_misspelt_object_name(struct repository *repo,
+				       const char *name,
+				       const char *prefix);
+enum get_oid_result get_oid_with_context(struct repository *repo, const char *str,
+					 unsigned flags, struct object_id *oid,
+					 struct object_context *oc);
+
+#define get_oid(str, oid)		repo_get_oid(the_repository, str, oid)
+#define get_oid_commit(str, oid)	repo_get_oid_commit(the_repository, str, oid)
+#define get_oid_committish(str, oid)	repo_get_oid_committish(the_repository, str, oid)
+#define get_oid_tree(str, oid)		repo_get_oid_tree(the_repository, str, oid)
+#define get_oid_treeish(str, oid)	repo_get_oid_treeish(the_repository, str, oid)
+#define get_oid_blob(str, oid)		repo_get_oid_blob(the_repository, str, oid)
+#define get_oid_mb(str, oid) 		repo_get_oid_mb(the_repository, str, oid)
+
+typedef int each_abbrev_fn(const struct object_id *oid, void *);
+int repo_for_each_abbrev(struct repository *r, const char *prefix, each_abbrev_fn, void *);
+#define for_each_abbrev(prefix, fn, data) repo_for_each_abbrev(the_repository, prefix, fn, data)
+
+int set_disambiguate_hint_config(const char *var, const char *value);
+
+/*
+ * Try to read a SHA1 in hexadecimal format from the 40 characters
+ * starting at hex.  Write the 20-byte result to sha1 in binary form.
+ * Return 0 on success.  Reading stops if a NUL is encountered in the
+ * input, so it is safe to pass this function an arbitrary
+ * null-terminated string.
+ */
+int get_sha1_hex(const char *hex, unsigned char *sha1);
+int get_oid_hex(const char *hex, struct object_id *sha1);
+
+/*
+ * Read `len` pairs of hexadecimal digits from `hex` and write the
+ * values to `binary` as `len` bytes. Return 0 on success, or -1 if
+ * the input does not consist of hex digits).
+ */
+int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
+
+/*
+ * Convert a binary hash to its hex equivalent. The `_r` variant is reentrant,
+ * and writes the NUL-terminated output to the buffer `out`, which must be at
+ * least `GIT_MAX_HEXSZ + 1` bytes, and returns a pointer to out for
+ * convenience.
+ *
+ * The non-`_r` variant returns a static buffer, but uses a ring of 4
+ * buffers, making it safe to make multiple calls for a single statement, like:
+ *
+ *   printf("%s -> %s", sha1_to_hex(one), sha1_to_hex(two));
+ */
+char *hash_to_hex_algop_r(char *buffer, const unsigned char *hash, const struct git_hash_algo *);
+char *sha1_to_hex_r(char *out, const unsigned char *sha1);
+char *oid_to_hex_r(char *out, const struct object_id *oid);
+char *hash_to_hex_algop(const unsigned char *hash, const struct git_hash_algo *);	/* static buffer result! */
+char *sha1_to_hex(const unsigned char *sha1);						/* same static buffer */
+char *hash_to_hex(const unsigned char *hash);						/* same static buffer */
+char *oid_to_hex(const struct object_id *oid);						/* same static buffer */
+
+/*
+ * Parse a 40-character hexadecimal object ID starting from hex, updating the
+ * pointer specified by end when parsing stops.  The resulting object ID is
+ * stored in oid.  Returns 0 on success.  Parsing will stop on the first NUL or
+ * other invalid character.  end is only updated on success; otherwise, it is
+ * unmodified.
+ */
+int parse_oid_hex(const char *hex, struct object_id *oid, const char **end);
+
+/*
+ * This reads short-hand syntax that not only evaluates to a commit
+ * object name, but also can act as if the end user spelled the name
+ * of the branch from the command line.
+ *
+ * - "@{-N}" finds the name of the Nth previous branch we were on, and
+ *   places the name of the branch in the given buf and returns the
+ *   number of characters parsed if successful.
+ *
+ * - "<branch>@{upstream}" finds the name of the other ref that
+ *   <branch> is configured to merge with (missing <branch> defaults
+ *   to the current branch), and places the name of the branch in the
+ *   given buf and returns the number of characters parsed if
+ *   successful.
+ *
+ * If the input is not of the accepted format, it returns a negative
+ * number to signal an error.
+ *
+ * If the input was ok but there are not N branch switches in the
+ * reflog, it returns 0.
+ *
+ * If "allowed" is non-zero, it is a treated as a bitfield of allowable
+ * expansions: local branches ("refs/heads/"), remote branches
+ * ("refs/remotes/"), or "HEAD". If no "allowed" bits are set, any expansion is
+ * allowed, even ones to refs outside of those namespaces.
+ */
+#define INTERPRET_BRANCH_LOCAL (1<<0)
+#define INTERPRET_BRANCH_REMOTE (1<<1)
+#define INTERPRET_BRANCH_HEAD (1<<2)
+int repo_interpret_branch_name(struct repository *r,
+			       const char *str, int len,
+			       struct strbuf *buf,
+			       unsigned allowed);
+#define interpret_branch_name(str, len, buf, allowed) \
+	repo_interpret_branch_name(the_repository, str, len, buf, allowed)
+
+int validate_headref(const char *ref);
+
+int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
+int df_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
+int name_compare(const char *name1, size_t len1, const char *name2, size_t len2);
+int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2);
+
+void *read_object_with_reference(struct repository *r,
+				 const struct object_id *oid,
+				 const char *required_type,
+				 unsigned long *size,
+				 struct object_id *oid_ret);
+
+struct object *repo_peel_to_type(struct repository *r,
+				 const char *name, int namelen,
+				 struct object *o, enum object_type);
+#define peel_to_type(name, namelen, obj, type) \
+	repo_peel_to_type(the_repository, name, namelen, obj, type)
+
+enum date_mode_type {
+	DATE_NORMAL = 0,
+	DATE_HUMAN,
+	DATE_RELATIVE,
+	DATE_SHORT,
+	DATE_ISO8601,
+	DATE_ISO8601_STRICT,
+	DATE_RFC2822,
+	DATE_STRFTIME,
+	DATE_RAW,
+	DATE_UNIX
+};
+
+struct date_mode {
+	enum date_mode_type type;
+	const char *strftime_fmt;
+	int local;
+};
+
+/*
+ * Convenience helper for passing a constant type, like:
+ *
+ *   show_date(t, tz, DATE_MODE(NORMAL));
+ */
+#define DATE_MODE(t) date_mode_from_type(DATE_##t)
+struct date_mode *date_mode_from_type(enum date_mode_type type);
+
+const char *show_date(timestamp_t time, int timezone, const struct date_mode *mode);
+void show_date_relative(timestamp_t time, const struct timeval *now,
+			struct strbuf *timebuf);
+void show_date_human(timestamp_t time, int tz, const struct timeval *now,
+			struct strbuf *timebuf);
+int parse_date(const char *date, struct strbuf *out);
+int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset);
+int parse_expiry_date(const char *date, timestamp_t *timestamp);
+void datestamp(struct strbuf *out);
+#define approxidate(s) approxidate_careful((s), NULL)
+timestamp_t approxidate_careful(const char *, int *);
+timestamp_t approxidate_relative(const char *date, const struct timeval *now);
+void parse_date_format(const char *format, struct date_mode *mode);
+int date_overflows(timestamp_t date);
+
+#define IDENT_STRICT	       1
+#define IDENT_NO_DATE	       2
+#define IDENT_NO_NAME	       4
+
+enum want_ident {
+	WANT_BLANK_IDENT,
+	WANT_AUTHOR_IDENT,
+	WANT_COMMITTER_IDENT
+};
+
+const char *git_author_info(int);
+const char *git_committer_info(int);
+const char *fmt_ident(const char *name, const char *email,
+		      enum want_ident whose_ident,
+		      const char *date_str, int);
+const char *fmt_name(enum want_ident);
+const char *ident_default_name(void);
+const char *ident_default_email(void);
+const char *git_editor(void);
+const char *git_sequence_editor(void);
+const char *git_pager(int stdout_is_tty);
+int is_terminal_dumb(void);
+int git_ident_config(const char *, const char *, void *);
+/*
+ * Prepare an ident to fall back on if the user didn't configure it.
+ */
+void prepare_fallback_ident(const char *name, const char *email);
+void reset_ident_date(void);
+
+struct ident_split {
+	const char *name_begin;
+	const char *name_end;
+	const char *mail_begin;
+	const char *mail_end;
+	const char *date_begin;
+	const char *date_end;
+	const char *tz_begin;
+	const char *tz_end;
+};
+/*
+ * Signals an success with 0, but time part of the result may be NULL
+ * if the input lacks timestamp and zone
+ */
+int split_ident_line(struct ident_split *, const char *, int);
+
+/*
+ * Like show_date, but pull the timestamp and tz parameters from
+ * the ident_split. It will also sanity-check the values and produce
+ * a well-known sentinel date if they appear bogus.
+ */
+const char *show_ident_date(const struct ident_split *id,
+			    const struct date_mode *mode);
+
+/*
+ * Compare split idents for equality or strict ordering. Note that we
+ * compare only the ident part of the line, ignoring any timestamp.
+ *
+ * Because there are two fields, we must choose one as the primary key; we
+ * currently arbitrarily pick the email.
+ */
+int ident_cmp(const struct ident_split *, const struct ident_split *);
+
+struct checkout {
+	struct index_state *istate;
+	const char *base_dir;
+	int base_dir_len;
+	struct delayed_checkout *delayed_checkout;
+	unsigned force:1,
+		 quiet:1,
+		 not_new:1,
+		 clone:1,
+		 refresh_cache:1;
+};
+#define CHECKOUT_INIT { NULL, "" }
+
+#define TEMPORARY_FILENAME_LENGTH 25
+int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath, int *nr_checkouts);
+void enable_delayed_checkout(struct checkout *state);
+int finish_delayed_checkout(struct checkout *state, int *nr_checkouts);
+/*
+ * Unlink the last component and schedule the leading directories for
+ * removal, such that empty directories get removed.
+ */
+void unlink_entry(const struct cache_entry *ce);
+
+struct cache_def {
+	struct strbuf path;
+	int flags;
+	int track_flags;
+	int prefix_len_stat_func;
+};
+#define CACHE_DEF_INIT { STRBUF_INIT, 0, 0, 0 }
+static inline void cache_def_clear(struct cache_def *cache)
+{
+	strbuf_release(&cache->path);
+}
+
+int has_symlink_leading_path(const char *name, int len);
+int threaded_has_symlink_leading_path(struct cache_def *, const char *, int);
+int check_leading_path(const char *name, int len);
+int has_dirs_only_path(const char *name, int len, int prefix_len);
+void schedule_dir_for_removal(const char *name, int len);
+void remove_scheduled_dirs(void);
+
+struct pack_window {
+	struct pack_window *next;
+	unsigned char *base;
+	off_t offset;
+	size_t len;
+	unsigned int last_used;
+	unsigned int inuse_cnt;
+};
+
+struct pack_entry {
+	off_t offset;
+	struct packed_git *p;
+};
+
+/*
+ * Create a temporary file rooted in the object database directory, or
+ * die on failure. The filename is taken from "pattern", which should have the
+ * usual "XXXXXX" trailer, and the resulting filename is written into the
+ * "template" buffer. Returns the open descriptor.
+ */
+int odb_mkstemp(struct strbuf *temp_filename, const char *pattern);
+
+/*
+ * Create a pack .keep file named "name" (which should generally be the output
+ * of odb_pack_name). Returns a file descriptor opened for writing, or -1 on
+ * error.
+ */
+int odb_pack_keep(const char *name);
+
+/*
+ * Set this to 0 to prevent oid_object_info_extended() from fetching missing
+ * blobs. This has a difference only if extensions.partialClone is set.
+ *
+ * Its default value is 1.
+ */
+extern int fetch_if_missing;
+
+/* Dumb servers support */
+int update_server_info(int);
+
+const char *get_log_output_encoding(void);
+const char *get_commit_output_encoding(void);
+
+/*
+ * This is a hack for test programs like test-dump-untracked-cache to
+ * ensure that they do not modify the untracked cache when reading it.
+ * Do not use it otherwise!
+ */
+extern int ignore_untracked_cache_config;
+
+int committer_ident_sufficiently_given(void);
+int author_ident_sufficiently_given(void);
+
+extern const char *git_commit_encoding;
+extern const char *git_log_output_encoding;
+extern const char *git_mailmap_file;
+extern const char *git_mailmap_blob;
+
+/* IO helper functions */
+void maybe_flush_or_die(FILE *, const char *);
+__attribute__((format (printf, 2, 3)))
+void fprintf_or_die(FILE *, const char *fmt, ...);
+
+#define COPY_READ_ERROR (-2)
+#define COPY_WRITE_ERROR (-3)
+int copy_fd(int ifd, int ofd);
+int copy_file(const char *dst, const char *src, int mode);
+int copy_file_with_time(const char *dst, const char *src, int mode);
+
+void write_or_die(int fd, const void *buf, size_t count);
+void fsync_or_die(int fd, const char *);
+
+ssize_t read_in_full(int fd, void *buf, size_t count);
+ssize_t write_in_full(int fd, const void *buf, size_t count);
+ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset);
+
+static inline ssize_t write_str_in_full(int fd, const char *str)
+{
+	return write_in_full(fd, str, strlen(str));
+}
+
+/**
+ * Open (and truncate) the file at path, write the contents of buf to it,
+ * and close it. Dies if any errors are encountered.
+ */
+void write_file_buf(const char *path, const char *buf, size_t len);
+
+/**
+ * Like write_file_buf(), but format the contents into a buffer first.
+ * Additionally, write_file() will append a newline if one is not already
+ * present, making it convenient to write text files:
+ *
+ *   write_file(path, "counter: %d", ctr);
+ */
+__attribute__((format (printf, 2, 3)))
+void write_file(const char *path, const char *fmt, ...);
+
+/* pager.c */
+void setup_pager(void);
+int pager_in_use(void);
+extern int pager_use_color;
+int term_columns(void);
+void term_clear_line(void);
+int decimal_width(uintmax_t);
+int check_pager_config(const char *cmd);
+void prepare_pager_args(struct child_process *, const char *pager);
+
+extern const char *editor_program;
+extern const char *askpass_program;
+extern const char *excludes_file;
+
+/* base85 */
+int decode_85(char *dst, const char *line, int linelen);
+void encode_85(char *buf, const unsigned char *data, int bytes);
+
+/* pkt-line.c */
+void packet_trace_identity(const char *prog);
+
+/* add */
+/*
+ * return 0 if success, 1 - if addition of a file failed and
+ * ADD_FILES_IGNORE_ERRORS was specified in flags
+ */
+int add_files_to_cache(const char *prefix, const struct pathspec *pathspec, int flags);
+
+/* diff.c */
+extern int diff_auto_refresh_index;
+
+/* match-trees.c */
+void shift_tree(struct repository *, const struct object_id *, const struct object_id *, struct object_id *, int);
+void shift_tree_by(struct repository *, const struct object_id *, const struct object_id *, struct object_id *, const char *);
+
+/*
+ * whitespace rules.
+ * used by both diff and apply
+ * last two digits are tab width
+ */
+#define WS_BLANK_AT_EOL         0100
+#define WS_SPACE_BEFORE_TAB     0200
+#define WS_INDENT_WITH_NON_TAB  0400
+#define WS_CR_AT_EOL           01000
+#define WS_BLANK_AT_EOF        02000
+#define WS_TAB_IN_INDENT       04000
+#define WS_TRAILING_SPACE      (WS_BLANK_AT_EOL|WS_BLANK_AT_EOF)
+#define WS_DEFAULT_RULE (WS_TRAILING_SPACE|WS_SPACE_BEFORE_TAB|8)
+#define WS_TAB_WIDTH_MASK        077
+/* All WS_* -- when extended, adapt diff.c emit_symbol */
+#define WS_RULE_MASK           07777
+extern unsigned whitespace_rule_cfg;
+unsigned whitespace_rule(struct index_state *, const char *);
+unsigned parse_whitespace_rule(const char *);
+unsigned ws_check(const char *line, int len, unsigned ws_rule);
+void ws_check_emit(const char *line, int len, unsigned ws_rule, FILE *stream, const char *set, const char *reset, const char *ws);
+char *whitespace_error_string(unsigned ws);
+void ws_fix_copy(struct strbuf *, const char *, int, unsigned, int *);
+int ws_blank_line(const char *line, int len, unsigned ws_rule);
+#define ws_tab_width(rule)     ((rule) & WS_TAB_WIDTH_MASK)
+
+/* ls-files */
+void overlay_tree_on_index(struct index_state *istate,
+			   const char *tree_name, const char *prefix);
+
+/* setup.c */
+struct startup_info {
+	int have_repository;
+	const char *prefix;
+};
+extern struct startup_info *startup_info;
+
+/* merge.c */
+struct commit_list;
+int try_merge_command(struct repository *r,
+		const char *strategy, size_t xopts_nr,
+		const char **xopts, struct commit_list *common,
+		const char *head_arg, struct commit_list *remotes);
+int checkout_fast_forward(struct repository *r,
+			  const struct object_id *from,
+			  const struct object_id *to,
+			  int overwrite_ignore);
+
+
+int sane_execvp(const char *file, char *const argv[]);
+
+/*
+ * A struct to encapsulate the concept of whether a file has changed
+ * since we last checked it. This uses criteria similar to those used
+ * for the index.
+ */
+struct stat_validity {
+	struct stat_data *sd;
+};
+
+void stat_validity_clear(struct stat_validity *sv);
+
+/*
+ * Returns 1 if the path is a regular file (or a symlink to a regular
+ * file) and matches the saved stat_validity, 0 otherwise.  A missing
+ * or inaccessible file is considered a match if the struct was just
+ * initialized, or if the previous update found an inaccessible file.
+ */
+int stat_validity_check(struct stat_validity *sv, const char *path);
+
+/*
+ * Update the stat_validity from a file opened at descriptor fd. If
+ * the file is missing, inaccessible, or not a regular file, then
+ * future calls to stat_validity_check will match iff one of those
+ * conditions continues to be true.
+ */
+void stat_validity_update(struct stat_validity *sv, int fd);
+
+int versioncmp(const char *s1, const char *s2);
+void sleep_millisec(int millisec);
+
+/*
+ * Create a directory and (if share is nonzero) adjust its permissions
+ * according to the shared_repository setting. Only use this for
+ * directories under $GIT_DIR.  Don't use it for working tree
+ * directories.
+ */
+void safe_create_dir(const char *dir, int share);
+
+/*
+ * Should we print an ellipsis after an abbreviated SHA-1 value
+ * when doing diff-raw output or indicating a detached HEAD?
+ */
+int print_sha1_ellipsis(void);
+
+/* Return 1 if the file is empty or does not exists, 0 otherwise. */
+int is_empty_or_missing_file(const char *filename);
+
+#endif /* CACHE_H */