$GIT_COMMON_DIR: a new environment variable
This variable is intended to support multiple working directories attached to a repository. Such a repository may have a main working directory, created by either "git init" or "git clone" and one or more linked working directories. These working directories and the main repository share the same repository directory. In linked working directories, $GIT_COMMON_DIR must be defined to point to the real repository directory and $GIT_DIR points to an unused subdirectory inside $GIT_COMMON_DIR. File locations inside the repository are reorganized from the linked worktree view point: - worktree-specific such as HEAD, logs/HEAD, index, other top-level refs and unrecognized files are from $GIT_DIR. - the rest like objects, refs, info, hooks, packed-refs, shallow... are from $GIT_COMMON_DIR (except info/sparse-checkout, but that's a separate patch) Scripts are supposed to retrieve paths in $GIT_DIR with "git rev-parse --git-path", which will take care of "$GIT_DIR vs $GIT_COMMON_DIR" business. The redirection is done by git_path(), git_pathdup() and strbuf_git_path(). The selected list of paths goes to $GIT_COMMON_DIR, not the other way around in case a developer adds a new worktree-specific file and it's accidentally promoted to be shared across repositories (this includes unknown files added by third party commands) The list of known files that belong to $GIT_DIR are: ADD_EDIT.patch BISECT_ANCESTORS_OK BISECT_EXPECTED_REV BISECT_LOG BISECT_NAMES CHERRY_PICK_HEAD COMMIT_MSG FETCH_HEAD HEAD MERGE_HEAD MERGE_MODE MERGE_RR NOTES_EDITMSG NOTES_MERGE_WORKTREE ORIG_HEAD REVERT_HEAD SQUASH_MSG TAG_EDITMSG fast_import_crash_* logs/HEAD next-index-* rebase-apply rebase-merge rsync-refs-* sequencer/* shallow_* Path mapping is NOT done for git_path_submodule(). Multi-checkouts are not supported as submodules. Helped-by: Jens Lehmann <Jens.Lehmann@web.de> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Nguyễn Thái Ngọc Duy committed
Nov 30, 2014 at 15:24 UTC
c7b3a3d2fe2688a30ddb8d516ed000eeda13c24e
6 files changed
+117
-19
Documentation/git.txt
+8
@@ -809,6 +809,14 @@ Git so take care if using Cogito etc.
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an explicit repository directory set via 'GIT_DIR' or on the
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command line.
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+'GIT_COMMON_DIR'::
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+ If this variable is set to a path, non-worktree files that are
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+ normally in $GIT_DIR will be taken from this path
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+ instead. Worktree-specific files such as HEAD or index are
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+ taken from $GIT_DIR. See linkgit:gitrepository-layout[5] for
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+ details. This variable has lower precedence than other path
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+ variables such as GIT_INDEX_FILE, GIT_OBJECT_DIRECTORY...
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+
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Git Commits
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~~~~~~~~~~~
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'GIT_AUTHOR_NAME'::
Documentation/gitrepository-layout.txt
+34
-11
@@ -46,6 +46,9 @@ of incomplete object store is not suitable to be published for
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use with dumb transports but otherwise is OK as long as
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`objects/info/alternates` points at the object stores it
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borrows from.
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++
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+This directory is ignored if $GIT_COMMON_DIR is set and
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+"$GIT_COMMON_DIR/objects" will be used instead.
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objects/[0-9a-f][0-9a-f]::
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A newly created object is stored in its own file.
@@ -92,7 +95,8 @@ refs::
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References are stored in subdirectories of this
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directory. The 'git prune' command knows to preserve
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objects reachable from refs found in this directory and
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- its subdirectories.
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+ its subdirectories. This directory is ignored if $GIT_COMMON_DIR
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+ is set and "$GIT_COMMON_DIR/refs" will be used instead.
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refs/heads/`name`::
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records tip-of-the-tree commit objects of branch `name`
@@ -114,7 +118,8 @@ refs/replace/`<obj-sha1>`::
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packed-refs::
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records the same information as refs/heads/, refs/tags/,
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and friends record in a more efficient way. See
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- linkgit:git-pack-refs[1].
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+ linkgit:git-pack-refs[1]. This file is ignored if $GIT_COMMON_DIR
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+ is set and "$GIT_COMMON_DIR/packed-refs" will be used instead.
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HEAD::
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A symref (see glossary) to the `refs/heads/` namespace
@@ -133,6 +138,11 @@ being a symref to point at the current branch. Such a state
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is often called 'detached HEAD.' See linkgit:git-checkout[1]
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for details.
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+config::
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+ Repository specific configuration file. This file is ignored
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+ if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/config" will be
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+ used instead.
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+
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branches::
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A slightly deprecated way to store shorthands to be used
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to specify a URL to 'git fetch', 'git pull' and 'git push'.
@@ -140,7 +150,10 @@ branches::
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'name' can be given to these commands in place of
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'repository' argument. See the REMOTES section in
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linkgit:git-fetch[1] for details. This mechanism is legacy
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- and not likely to be found in modern repositories.
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+ and not likely to be found in modern repositories. This
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+ directory is ignored if $GIT_COMMON_DIR is set and
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+ "$GIT_COMMON_DIR/branches" will be used instead.
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+
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hooks::
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Hooks are customization scripts used by various Git
@@ -149,7 +162,9 @@ hooks::
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default. To enable, the `.sample` suffix has to be
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removed from the filename by renaming.
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Read linkgit:githooks[5] for more details about
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- each hook.
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+ each hook. This directory is ignored if $GIT_COMMON_DIR is set
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+ and "$GIT_COMMON_DIR/hooks" will be used instead.
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+
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index::
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The current index file for the repository. It is
@@ -161,7 +176,8 @@ sharedindex.<SHA-1>::
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info::
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Additional information about the repository is recorded
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- in this directory.
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+ in this directory. This directory is ignored if $GIT_COMMON_DIR
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+ is set and "$GIT_COMMON_DIR/index" will be used instead.
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info/refs::
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This file helps dumb transports discover what refs are
@@ -201,12 +217,15 @@ remotes::
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when interacting with remote repositories via 'git fetch',
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'git pull' and 'git push' commands. See the REMOTES section
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in linkgit:git-fetch[1] for details. This mechanism is legacy
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- and not likely to be found in modern repositories.
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+ and not likely to be found in modern repositories. This
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+ directory is ignored if $GIT_COMMON_DIR is set and
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+ "$GIT_COMMON_DIR/remotes" will be used instead.
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logs::
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- Records of changes made to refs are stored in this
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- directory. See linkgit:git-update-ref[1]
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- for more information.
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+ Records of changes made to refs are stored in this directory.
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+ See linkgit:git-update-ref[1] for more information. This
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+ directory is ignored if $GIT_COMMON_DIR is set and
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+ "$GIT_COMMON_DIR/logs" will be used instead.
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logs/refs/heads/`name`::
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Records all changes made to the branch tip named `name`.
@@ -217,10 +236,14 @@ logs/refs/tags/`name`::
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shallow::
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This is similar to `info/grafts` but is internally used
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and maintained by shallow clone mechanism. See `--depth`
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- option to linkgit:git-clone[1] and linkgit:git-fetch[1].
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+ option to linkgit:git-clone[1] and linkgit:git-fetch[1]. This
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+ file is ignored if $GIT_COMMON_DIR is set and
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+ "$GIT_COMMON_DIR/shallow" will be used instead.
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modules::
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- Contains the git-repositories of the submodules.
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+ Contains the git-repositories of the submodules. This
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+ directory is ignored if $GIT_COMMON_DIR is set and
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+ "$GIT_COMMON_DIR/modules" will be used instead.
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SEE ALSO
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--------
cache.h
+3
-1
@@ -377,6 +377,7 @@ static inline enum object_type object_type(unsigned int mode)
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/* Double-check local_repo_env below if you add to this list. */
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#define GIT_DIR_ENVIRONMENT "GIT_DIR"
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+#define GIT_COMMON_DIR_ENVIRONMENT "GIT_COMMON_DIR"
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#define GIT_NAMESPACE_ENVIRONMENT "GIT_NAMESPACE"
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#define GIT_WORK_TREE_ENVIRONMENT "GIT_WORK_TREE"
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#define GIT_PREFIX_ENVIRONMENT "GIT_PREFIX"
@@ -430,6 +431,7 @@ extern int is_inside_git_dir(void);
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extern char *git_work_tree_cfg;
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extern int is_inside_work_tree(void);
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extern const char *get_git_dir(void);
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+extern const char *get_git_common_dir(void);
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extern int is_git_directory(const char *path);
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extern char *get_object_directory(void);
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extern char *get_index_file(void);
@@ -617,7 +619,7 @@ extern int fsync_object_files;
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extern int core_preload_index;
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extern int core_apply_sparse_checkout;
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extern int precomposed_unicode;
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-extern int git_db_env, git_index_env, git_graft_env;
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+extern int git_db_env, git_index_env, git_graft_env, git_common_dir_env;
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/*
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* The character that begins a commented line in user-editable file
environment.c
+22
-7
@@ -81,9 +81,9 @@ static char *work_tree;
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static const char *namespace;
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static size_t namespace_len;
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-static const char *git_dir;
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+static const char *git_dir, *git_common_dir;
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static char *git_object_dir, *git_index_file, *git_graft_file;
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-int git_db_env, git_index_env, git_graft_env;
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+int git_db_env, git_index_env, git_graft_env, git_common_dir_env;
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/*
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* Repository-local GIT_* environment variables; see cache.h for details.
@@ -101,6 +101,7 @@ const char * const local_repo_env[] = {
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NO_REPLACE_OBJECTS_ENVIRONMENT,
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GIT_PREFIX_ENVIRONMENT,
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GIT_SHALLOW_FILE_ENVIRONMENT,
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+ GIT_COMMON_DIR_ENVIRONMENT,
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NULL
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};
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@@ -125,8 +126,8 @@ static char *expand_namespace(const char *raw_namespace)
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return strbuf_detach(&buf, NULL);
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}
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-static char *git_path_from_env(const char *envvar, const char *path,
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- int *fromenv)
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+static char *git_path_from_env(const char *envvar, const char *git_dir,
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+ const char *path, int *fromenv)
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{
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const char *value = getenv(envvar);
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if (!value) {
@@ -149,9 +150,18 @@ static void setup_git_env(void)
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git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
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gitfile = read_gitfile(git_dir);
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git_dir = xstrdup(gitfile ? gitfile : git_dir);
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- git_object_dir = git_path_from_env(DB_ENVIRONMENT, "objects", &git_db_env);
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- git_index_file = git_path_from_env(INDEX_ENVIRONMENT, "index", &git_index_env);
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- git_graft_file = git_path_from_env(GRAFT_ENVIRONMENT, "info/grafts", &git_graft_env);
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+ git_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
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+ if (git_common_dir) {
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+ git_common_dir_env = 1;
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+ git_common_dir = xstrdup(git_common_dir);
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+ } else
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+ git_common_dir = git_dir;
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+ git_object_dir = git_path_from_env(DB_ENVIRONMENT, git_common_dir,
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+ "objects", &git_db_env);
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+ git_index_file = git_path_from_env(INDEX_ENVIRONMENT, git_dir,
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+ "index", &git_index_env);
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+ git_graft_file = git_path_from_env(GRAFT_ENVIRONMENT, git_common_dir,
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+ "info/grafts", &git_graft_env);
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if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
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check_replace_refs = 0;
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namespace = expand_namespace(getenv(GIT_NAMESPACE_ENVIRONMENT));
@@ -174,6 +184,11 @@ const char *get_git_dir(void)
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return git_dir;
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}
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+const char *get_git_common_dir(void)
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+{
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+ return git_common_dir;
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+}
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+
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const char *get_git_namespace(void)
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{
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if (!namespace)
path.c
+34
@@ -90,6 +90,38 @@ static void replace_dir(struct strbuf *buf, int len, const char *newdir)
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buf->buf[newlen] = '/';
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}
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+static const char *common_list[] = {
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+ "/branches", "/hooks", "/info", "/logs", "/lost-found", "/modules",
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+ "/objects", "/refs", "/remotes", "/rr-cache", "/svn",
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+ "config", "gc.pid", "packed-refs", "shallow",
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+ NULL
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+};
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+
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+static void update_common_dir(struct strbuf *buf, int git_dir_len)
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+{
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+ char *base = buf->buf + git_dir_len;
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+ const char **p;
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+
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+ if (is_dir_file(base, "logs", "HEAD"))
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+ return; /* keep this in $GIT_DIR */
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+ for (p = common_list; *p; p++) {
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+ const char *path = *p;
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+ int is_dir = 0;
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+ if (*path == '/') {
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+ path++;
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+ is_dir = 1;
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+ }
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+ if (is_dir && dir_prefix(base, path)) {
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+ replace_dir(buf, git_dir_len, get_git_common_dir());
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+ return;
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+ }
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+ if (!is_dir && !strcmp(base, path)) {
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+ replace_dir(buf, git_dir_len, get_git_common_dir());
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+ return;
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+ }
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+ }
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+}
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+
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static void adjust_git_path(struct strbuf *buf, int git_dir_len)
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{
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const char *base = buf->buf + git_dir_len;
@@ -101,6 +133,8 @@ static void adjust_git_path(struct strbuf *buf, int git_dir_len)
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get_index_file(), strlen(get_index_file()));
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else if (git_db_env && dir_prefix(base, "objects"))
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replace_dir(buf, git_dir_len + 7, get_object_directory());
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+ else if (git_common_dir_env)
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+ update_common_dir(buf, git_dir_len);
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}
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static void do_git_path(struct strbuf *buf, const char *fmt, va_list args)
t/t0060-path-utils.sh
+16
@@ -262,5 +262,21 @@ test_expect_success 'setup fake objects directory foo' 'mkdir foo'
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test_git_path GIT_OBJECT_DIRECTORY=foo objects foo
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test_git_path GIT_OBJECT_DIRECTORY=foo objects/foo foo/foo
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test_git_path GIT_OBJECT_DIRECTORY=foo objects2 .git/objects2
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+test_expect_success 'setup common repository' 'git --git-dir=bar init'
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+test_git_path GIT_COMMON_DIR=bar index .git/index
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+test_git_path GIT_COMMON_DIR=bar HEAD .git/HEAD
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+test_git_path GIT_COMMON_DIR=bar logs/HEAD .git/logs/HEAD
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+test_git_path GIT_COMMON_DIR=bar objects bar/objects
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+test_git_path GIT_COMMON_DIR=bar objects/bar bar/objects/bar
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+test_git_path GIT_COMMON_DIR=bar info/exclude bar/info/exclude
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+test_git_path GIT_COMMON_DIR=bar info/grafts bar/info/grafts
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+test_git_path GIT_COMMON_DIR=bar remotes/bar bar/remotes/bar
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+test_git_path GIT_COMMON_DIR=bar branches/bar bar/branches/bar
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+test_git_path GIT_COMMON_DIR=bar logs/refs/heads/master bar/logs/refs/heads/master
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+test_git_path GIT_COMMON_DIR=bar refs/heads/master bar/refs/heads/master
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+test_git_path GIT_COMMON_DIR=bar hooks/me bar/hooks/me
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+test_git_path GIT_COMMON_DIR=bar config bar/config
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+test_git_path GIT_COMMON_DIR=bar packed-refs bar/packed-refs
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+test_git_path GIT_COMMON_DIR=bar shallow bar/shallow
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test_done