git-commit-vandalism/environment.c
Jeff King b9605bc4f2 config: only read .git/config from configured repos
When git_config() runs, it looks in the system, user-wide,
and repo-level config files. It gets the latter by calling
git_pathdup(), which in turn calls get_git_dir(). If we
haven't set up the git repository yet, this may simply
return ".git", and we will look at ".git/config".  This
seems like it would be helpful (presumably we haven't set up
the repository yet, so it tries to find it), but it turns
out to be a bad idea for a few reasons:

  - it's not sufficient, and therefore hides bugs in a
    confusing way. Config will be respected if commands are
    run from the top-level of the working tree, but not from
    a subdirectory.

  - it's not always true that we haven't set up the
    repository _yet_; we may not want to do it at all. For
    instance, if you run "git init /some/path" from inside
    another repository, it should not load config from the
    existing repository.

  - there might be a path ".git/config", but it is not the
    actual repository we would find via setup_git_directory().
    This may happen, e.g., if you are storing a git
    repository inside another git repository, but have
    munged one of the files in such a way that the
    inner repository is not valid (e.g., by removing HEAD).

We have at least two bugs of the second type in git-init,
introduced by ae5f677 (lazily load core.sharedrepository,
2016-03-11). It causes init to use git_configset(), which
loads all of the config, including values from the current
repo (if any).  This shows up in two ways:

  1. If we happen to be in an existing repository directory,
     we'll read and respect core.sharedrepository from it,
     even though it should have no bearing on the new
     repository. A new test in t1301 covers this.

  2. Similarly, if we're in an existing repo that sets
     core.logallrefupdates, that will cause init to fail to
     set it in a newly created repository (because it thinks
     that the user's templates already did so). A new test
     in t0001 covers this.

We also need to adjust an existing test in t1302, which
gives another example of why this patch is an improvement.

That test creates an embedded repository with a bogus
core.repositoryformatversion of "99". It wants to make sure
that we actually stop at the bogus repo rather than
continuing upward to find the outer repo. So it checks that
"git config core.repositoryformatversion" returns 99. But
that only works because we blindly read ".git/config", even
though we _know_ we're in a repository whose vintage we do
not understand.

After this patch, we avoid reading config from the unknown
vintage repository at all, which is a safer choice.  But we
need to tweak the test, since core.repositoryformatversion
will not return 99; it will claim that it could not find the
variable at all.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-13 15:45:45 -07:00

353 lines
9.3 KiB
C

/*
* We put all the git config variables in this same object
* file, so that programs can link against the config parser
* without having to link against all the rest of git.
*
* In particular, no need to bring in libz etc unless needed,
* even if you might want to know where the git directory etc
* are.
*/
#include "cache.h"
#include "refs.h"
#include "fmt-merge-msg.h"
#include "commit.h"
int trust_executable_bit = 1;
int trust_ctime = 1;
int check_stat = 1;
int has_symlinks = 1;
int minimum_abbrev = 4, default_abbrev = 7;
int ignore_case;
int assume_unchanged;
int prefer_symlink_refs;
int is_bare_repository_cfg = -1; /* unspecified */
int log_all_ref_updates = -1; /* unspecified */
int warn_ambiguous_refs = 1;
int warn_on_object_refname_ambiguity = 1;
int ref_paranoia = -1;
int repository_format_precious_objects;
const char *git_commit_encoding;
const char *git_log_output_encoding;
const char *apply_default_whitespace;
const char *apply_default_ignorewhitespace;
const char *git_attributes_file;
int zlib_compression_level = Z_BEST_SPEED;
int core_compression_level;
int core_compression_seen;
int fsync_object_files;
size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE;
size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT;
size_t delta_base_cache_limit = 96 * 1024 * 1024;
unsigned long big_file_threshold = 512 * 1024 * 1024;
int pager_use_color = 1;
const char *editor_program;
const char *askpass_program;
const char *excludes_file;
enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
int check_replace_refs = 1;
char *git_replace_ref_base;
enum eol core_eol = EOL_UNSET;
enum safe_crlf safe_crlf = SAFE_CRLF_WARN;
unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
enum rebase_setup_type autorebase = AUTOREBASE_NEVER;
enum push_default_type push_default = PUSH_DEFAULT_UNSPECIFIED;
#ifndef OBJECT_CREATION_MODE
#define OBJECT_CREATION_MODE OBJECT_CREATION_USES_HARDLINKS
#endif
enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE;
char *notes_ref_name;
int grafts_replace_parents = 1;
int core_apply_sparse_checkout;
int merge_log_config = -1;
int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
unsigned long pack_size_limit_cfg;
enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
#ifndef PROTECT_HFS_DEFAULT
#define PROTECT_HFS_DEFAULT 0
#endif
int protect_hfs = PROTECT_HFS_DEFAULT;
#ifndef PROTECT_NTFS_DEFAULT
#define PROTECT_NTFS_DEFAULT 0
#endif
int protect_ntfs = PROTECT_NTFS_DEFAULT;
/*
* The character that begins a commented line in user-editable file
* that is subject to stripspace.
*/
char comment_line_char = '#';
int auto_comment_line_char;
/* Parallel index stat data preload? */
int core_preload_index = 1;
/*
* 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!
*/
int ignore_untracked_cache_config;
/* This is set by setup_git_dir_gently() and/or git_default_config() */
char *git_work_tree_cfg;
static char *work_tree;
static const char *namespace;
static size_t namespace_len;
static const char *git_dir, *git_common_dir;
static char *git_object_dir, *git_index_file, *git_graft_file;
int git_db_env, git_index_env, git_graft_env, git_common_dir_env;
/*
* Repository-local GIT_* environment variables; see cache.h for details.
*/
const char * const local_repo_env[] = {
ALTERNATE_DB_ENVIRONMENT,
CONFIG_ENVIRONMENT,
CONFIG_DATA_ENVIRONMENT,
DB_ENVIRONMENT,
GIT_DIR_ENVIRONMENT,
GIT_WORK_TREE_ENVIRONMENT,
GIT_IMPLICIT_WORK_TREE_ENVIRONMENT,
GRAFT_ENVIRONMENT,
INDEX_ENVIRONMENT,
NO_REPLACE_OBJECTS_ENVIRONMENT,
GIT_REPLACE_REF_BASE_ENVIRONMENT,
GIT_PREFIX_ENVIRONMENT,
GIT_SHALLOW_FILE_ENVIRONMENT,
GIT_COMMON_DIR_ENVIRONMENT,
NULL
};
static char *expand_namespace(const char *raw_namespace)
{
struct strbuf buf = STRBUF_INIT;
struct strbuf **components, **c;
if (!raw_namespace || !*raw_namespace)
return xstrdup("");
strbuf_addstr(&buf, raw_namespace);
components = strbuf_split(&buf, '/');
strbuf_reset(&buf);
for (c = components; *c; c++)
if (strcmp((*c)->buf, "/") != 0)
strbuf_addf(&buf, "refs/namespaces/%s", (*c)->buf);
strbuf_list_free(components);
if (check_refname_format(buf.buf, 0))
die("bad git namespace path \"%s\"", raw_namespace);
strbuf_addch(&buf, '/');
return strbuf_detach(&buf, NULL);
}
static char *git_path_from_env(const char *envvar, const char *git_dir,
const char *path, int *fromenv)
{
const char *value = getenv(envvar);
if (!value)
return xstrfmt("%s/%s", git_dir, path);
if (fromenv)
*fromenv = 1;
return xstrdup(value);
}
static void setup_git_env(void)
{
struct strbuf sb = STRBUF_INIT;
const char *gitfile;
const char *shallow_file;
const char *replace_ref_base;
git_dir = getenv(GIT_DIR_ENVIRONMENT);
if (!git_dir)
git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
gitfile = read_gitfile(git_dir);
git_dir = xstrdup(gitfile ? gitfile : git_dir);
if (get_common_dir(&sb, git_dir))
git_common_dir_env = 1;
git_common_dir = strbuf_detach(&sb, NULL);
git_object_dir = git_path_from_env(DB_ENVIRONMENT, git_common_dir,
"objects", &git_db_env);
git_index_file = git_path_from_env(INDEX_ENVIRONMENT, git_dir,
"index", &git_index_env);
git_graft_file = git_path_from_env(GRAFT_ENVIRONMENT, git_common_dir,
"info/grafts", &git_graft_env);
if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
check_replace_refs = 0;
replace_ref_base = getenv(GIT_REPLACE_REF_BASE_ENVIRONMENT);
git_replace_ref_base = xstrdup(replace_ref_base ? replace_ref_base
: "refs/replace/");
namespace = expand_namespace(getenv(GIT_NAMESPACE_ENVIRONMENT));
namespace_len = strlen(namespace);
shallow_file = getenv(GIT_SHALLOW_FILE_ENVIRONMENT);
if (shallow_file)
set_alternate_shallow_file(shallow_file, 0);
}
int is_bare_repository(void)
{
/* if core.bare is not 'false', let's see if there is a work tree */
return is_bare_repository_cfg && !get_git_work_tree();
}
int have_git_dir(void)
{
return startup_info->have_repository
|| git_dir
|| getenv(GIT_DIR_ENVIRONMENT);
}
const char *get_git_dir(void)
{
if (!git_dir)
setup_git_env();
return git_dir;
}
const char *get_git_common_dir(void)
{
return git_common_dir;
}
const char *get_git_namespace(void)
{
if (!namespace)
setup_git_env();
return namespace;
}
const char *strip_namespace(const char *namespaced_ref)
{
if (!starts_with(namespaced_ref, get_git_namespace()))
return NULL;
return namespaced_ref + namespace_len;
}
static int git_work_tree_initialized;
/*
* Note. This works only before you used a work tree. This was added
* primarily to support git-clone to work in a new repository it just
* created, and is not meant to flip between different work trees.
*/
void set_git_work_tree(const char *new_work_tree)
{
if (git_work_tree_initialized) {
new_work_tree = real_path(new_work_tree);
if (strcmp(new_work_tree, work_tree))
die("internal error: work tree has already been set\n"
"Current worktree: %s\nNew worktree: %s",
work_tree, new_work_tree);
return;
}
git_work_tree_initialized = 1;
work_tree = xstrdup(real_path(new_work_tree));
}
const char *get_git_work_tree(void)
{
return work_tree;
}
char *get_object_directory(void)
{
if (!git_object_dir)
setup_git_env();
return git_object_dir;
}
int odb_mkstemp(char *template, size_t limit, const char *pattern)
{
int fd;
/*
* we let the umask do its job, don't try to be more
* restrictive except to remove write permission.
*/
int mode = 0444;
snprintf(template, limit, "%s/%s",
get_object_directory(), pattern);
fd = git_mkstemp_mode(template, mode);
if (0 <= fd)
return fd;
/* slow path */
/* some mkstemp implementations erase template on failure */
snprintf(template, limit, "%s/%s",
get_object_directory(), pattern);
safe_create_leading_directories(template);
return xmkstemp_mode(template, mode);
}
int odb_pack_keep(char *name, size_t namesz, const unsigned char *sha1)
{
int fd;
snprintf(name, namesz, "%s/pack/pack-%s.keep",
get_object_directory(), sha1_to_hex(sha1));
fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
if (0 <= fd)
return fd;
/* slow path */
safe_create_leading_directories(name);
return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
}
char *get_index_file(void)
{
if (!git_index_file)
setup_git_env();
return git_index_file;
}
char *get_graft_file(void)
{
if (!git_graft_file)
setup_git_env();
return git_graft_file;
}
int set_git_dir(const char *path)
{
if (setenv(GIT_DIR_ENVIRONMENT, path, 1))
return error("Could not set GIT_DIR to '%s'", path);
setup_git_env();
return 0;
}
const char *get_log_output_encoding(void)
{
return git_log_output_encoding ? git_log_output_encoding
: get_commit_output_encoding();
}
const char *get_commit_output_encoding(void)
{
return git_commit_encoding ? git_commit_encoding : "UTF-8";
}
static int the_shared_repository = PERM_UMASK;
static int need_shared_repository_from_config = 1;
void set_shared_repository(int value)
{
the_shared_repository = value;
need_shared_repository_from_config = 0;
}
int get_shared_repository(void)
{
if (need_shared_repository_from_config) {
const char *var = "core.sharedrepository";
const char *value;
if (!git_config_get_value(var, &value))
the_shared_repository = git_config_perm(var, value);
need_shared_repository_from_config = 0;
}
return the_shared_repository;
}