RFC: system-wide config file in %PROGRAMDATA%

Documentation/config.txt

@@ -6,9 +6,8 @@ the Git commands' behavior. The `.git/config` file in each repository
 is used to store the configuration for that repository, and
 `$HOME/.gitconfig` is used to store a per-user configuration as
 fallback values for the `.git/config` file. The file `/etc/gitconfig`
-can be used to store a system-wide default configuration. On Windows,
-configuration can also be stored in `C:\ProgramData\Git\config`; This
-file will be used also by libgit2-based software.
+can be used to store a system-wide default configuration
+(`%PROGRAMDATA%\Git\gitconfig` on Windows).
 
 The configuration variables are used by both the Git plumbing
 and the porcelains. The variables are divided into sections, wherein

Documentation/git-config.txt

@@ -117,12 +117,14 @@ See also <<FILES>>.
 
 --system::
 	For writing options: write to system-wide
-	`$(prefix)/etc/gitconfig` rather than the repository
+	`/etc/gitconfig` rather than the repository
 	`.git/config`.
 +
-For reading options: read only from system-wide `$(prefix)/etc/gitconfig`
+For reading options: read only from system-wide `/etc/gitconfig`
 rather than from all available files.
 +
+On Windows, the system-wide config file is `%PROGRAMDATA%\Git\gitconfig`.
++
 See also <<FILES>>.
 
 --local::
@@ -221,11 +223,21 @@ See also <<FILES>>.
 FILES
 -----
 
-If not set explicitly with '--file', there are four files where
+If not set explicitly with '--file', there are five files where
 'git config' will search for configuration options:
 
 $(prefix)/etc/gitconfig::
-	System-wide configuration file.
+	Installation-specific configuration file, where '$(prefix)' is the
+	installation root directory specified via 'make prefix=...'. This allows
+	software distributions to provide installation-specific default values
+	(e.g. 'help.format=html' if the installation only includes html pages).
+
+/etc/gitconfig::
+	System-wide configuration file (`%PROGRAMDATA%\Git\gitconfig` on Windows).
++
+If git was built with relative `$(sysconfdir)`, this file will not be
+used, and the '--system' option refers to the installation-specific
+`$(prefix)/etc/gitconfig` instead.
 
 $XDG_CONFIG_HOME/git/config::
 	Second user-specific configuration file. If $XDG_CONFIG_HOME is not set
@@ -268,11 +280,11 @@ ENVIRONMENT
 GIT_CONFIG::
 	Take the configuration from the given file instead of .git/config.
 	Using the "--global" option forces this to ~/.gitconfig. Using the
-	"--system" option forces this to $(prefix)/etc/gitconfig.
+	"--system" option forces this to /etc/gitconfig.
 
 GIT_CONFIG_NOSYSTEM::
-	Whether to skip reading settings from the system-wide
-	$(prefix)/etc/gitconfig file. See linkgit:git[1] for details.
+	Whether to skip reading settings from the installation-specific	and
+	system-wide /etc/gitconfig files. See linkgit:git[1] for details.
 
 See also <<FILES>>.
 

Documentation/git.txt

@@ -939,8 +939,8 @@ for further details.
 	on the terminal (e.g., when asking for HTTP authentication).
 
 'GIT_CONFIG_NOSYSTEM'::
-	Whether to skip reading settings from the system-wide
-	`$(prefix)/etc/gitconfig` file.  This environment variable can
+	Whether to skip reading settings from the installation-specific and
+	system-wide `/etc/gitconfig` files. This environment variable can
 	be used along with `$HOME` and `$XDG_CONFIG_HOME` to create a
 	predictable environment for a picky script, or you can set it
 	temporarily to avoid using a buggy `/etc/gitconfig` file while

Documentation/gitattributes.txt

@@ -84,7 +84,7 @@ for a single user should be placed in a file specified by the
 Its default value is $XDG_CONFIG_HOME/git/attributes. If $XDG_CONFIG_HOME
 is either not set or empty, $HOME/.config/git/attributes is used instead.
 Attributes for all users on a system should be placed in the
-`$(prefix)/etc/gitattributes` file.
+`/etc/gitattributes` file (`%PROGRAMDATA%\Git\gitattributes` on Windows).
 
 Sometimes you would need to override an setting of an attribute
 for a path to `Unspecified` state.  This can be done by listing

config.c

@@ -1166,14 +1166,32 @@ static int git_config_from_blob_ref(config_fn_t fn,
 	return git_config_from_blob_sha1(fn, name, sha1, data);
 }
 
+static const char *etc_gitconfig = ETC_GITCONFIG;
+
 const char *git_etc_gitconfig(void)
 {
 	static const char *system_wide;
 	if (!system_wide)
-		system_wide = system_path(ETC_GITCONFIG);
+		system_wide = system_path(etc_gitconfig);
 	return system_wide;
 }
 
+static const char *git_inst_gitconfig(void)
+{
+	static const char *installation_defaults;
+	if (!installation_defaults) {
+		/*
+		 * if ETC_GITCONFIG as configured in the Makefile is an absolute path,
+		 * also load installation-specific defaults (relative to $(prefix))
+		 */
+		if (is_dir_sep(*etc_gitconfig))
+			installation_defaults = system_path(etc_gitconfig + 1);
+		else
+			installation_defaults = "";
+	}
+	return *installation_defaults ? installation_defaults : NULL;
+}
+
 /*
  * Parse environment variable 'k' as a boolean (in various
  * possible spellings); if missing, use the default value 'def'.
@@ -1201,41 +1219,38 @@ int git_config_system(void)
 	return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 }
 
+static inline int config_early_helper(config_fn_t fn, const char *filename,
+		void *data, unsigned access_flags, int count) {
+	if (!filename || access_or_die(filename, R_OK, access_flags))
+		/* no file: return unchanged */
+		return count;
+
+	if (git_config_from_file(fn, filename, data))
+		/* error: decrement or start counting errors at -1 */
+		return count < 0 ? count - 1 : -1;
+	else
+		/* ok: increment unless we had errors before */
+		return count < 0 ? count : count + 1;
+}
+
 int git_config_early(config_fn_t fn, void *data, const char *repo_config)
 {
-	int ret = 0, found = 0;
-	const char *super_config = git_super_config();
+	/* count loaded files (> 0) or errors (< 0) */
+	int cnt = 0;
 	char *xdg_config = NULL;
 	char *user_config = NULL;
 
 	home_config_paths(&user_config, &xdg_config, "config");
 
-	if (super_config && git_config_system() &&
-			!access(super_config, R_OK)) {
-		ret += git_config_from_file(fn, super_config, data);
-		found += 1;
+	if (git_config_system()) {
+		cnt = config_early_helper(fn, git_inst_gitconfig(), data, 0, cnt);
+		cnt = config_early_helper(fn, git_etc_gitconfig(), data, 0, cnt);
 	}
 
-	if (git_config_system() && !access_or_die(git_etc_gitconfig(), R_OK, 0)) {
-		ret += git_config_from_file(fn, git_etc_gitconfig(),
-					    data);
-		found += 1;
-	}
+	cnt = config_early_helper(fn, xdg_config, data, ACCESS_EACCES_OK, cnt);
+	cnt = config_early_helper(fn, user_config, data, ACCESS_EACCES_OK, cnt);
 
-	if (xdg_config && !access_or_die(xdg_config, R_OK, ACCESS_EACCES_OK)) {
-		ret += git_config_from_file(fn, xdg_config, data);
-		found += 1;
-	}
-
-	if (user_config && !access_or_die(user_config, R_OK, ACCESS_EACCES_OK)) {
-		ret += git_config_from_file(fn, user_config, data);
-		found += 1;
-	}
-
-	if (repo_config && !access_or_die(repo_config, R_OK, 0)) {
-		ret += git_config_from_file(fn, repo_config, data);
-		found += 1;
-	}
+	cnt = config_early_helper(fn, repo_config, data, 0, cnt);
 
 	switch (git_config_from_parameters(fn, data)) {
 	case -1: /* error */
@@ -1244,13 +1259,14 @@ int git_config_early(config_fn_t fn, void *data, const char *repo_config)
 	case 0: /* found nothing */
 		break;
 	default: /* found at least one item */
-		found++;
+		if (cnt >= 0)
+			cnt++;
 		break;
 	}
 
 	free(xdg_config);
 	free(user_config);
-	return ret == 0 ? found : ret;
+	return cnt;
 }
 
 int git_config_with_options(config_fn_t fn, void *data,
@@ -1932,6 +1948,24 @@ int git_config_parse_key(const char *key, char **store_key, int *baselen_)
 	return -CONFIG_INVALID_KEY;
 }
 
+
+static int lock_config_file(const char *config_filename,
+		struct lock_file **result)
+{
+	int fd;
+	/* make sure the parent directory exists */
+	if (safe_create_leading_directories_const(config_filename)) {
+		error("could not create parent directory of %s", config_filename);
+		return -1;
+	}
+	*result = xcalloc(1, sizeof(struct lock_file));
+	fd = hold_lock_file_for_update(*result, config_filename, 0);
+	if (fd < 0)
+		error("could not lock config file %s: %s", config_filename,
+				strerror(errno));
+	return fd;
+}
+
 /*
  * If value==NULL, unset in (remove from) config,
  * if value_regex!=NULL, disregard key/value pairs where value does not match.
@@ -1980,10 +2014,8 @@ int git_config_set_multivar_in_file(const char *config_filename,
 	 * The lock serves a purpose in addition to locking: the new
 	 * contents of .git/config will be written into it.
 	 */
-	lock = xcalloc(1, sizeof(struct lock_file));
-	fd = hold_lock_file_for_update(lock, config_filename, 0);
+	fd = lock_config_file(config_filename, &lock);
 	if (fd < 0) {
-		error("could not lock config file %s: %s", config_filename, strerror(errno));
 		free(store.key);
 		ret = CONFIG_NO_LOCK;
 		goto out_free;
@@ -2251,12 +2283,9 @@ int git_config_rename_section_in_file(const char *config_filename,
 	if (!config_filename)
 		config_filename = filename_buf = git_pathdup("config");
 
-	lock = xcalloc(1, sizeof(struct lock_file));
-	out_fd = hold_lock_file_for_update(lock, config_filename, 0);
-	if (out_fd < 0) {
-		ret = error("could not lock config file %s", config_filename);
+	out_fd = lock_config_file(config_filename, &lock);
+	if (out_fd < 0)
 		goto out;
-	}
 
 	if (!(config_file = fopen(config_filename, "rb"))) {
 		/* no config file means nothing to rename, no error */

config.mak.uname

@@ -330,6 +330,7 @@ endif
 ifeq ($(uname_S),Windows)
 	GIT_VERSION := $(GIT_VERSION).MSVC
 	pathsep = ;
+	sysconfdir = /etc
 	HAVE_ALLOCA_H = YesPlease
 	NO_PREAD = YesPlease
 	NEEDS_CRYPTO_WITH_SSL = YesPlease
@@ -484,6 +485,7 @@ ifeq ($(uname_S),NONSTOP_KERNEL)
 endif
 ifneq (,$(findstring MINGW,$(uname_S)))
 	pathsep = ;
+	sysconfdir = /etc
 	HAVE_ALLOCA_H = YesPlease
 	NO_PREAD = YesPlease
 	NEEDS_CRYPTO_WITH_SSL = YesPlease
@@ -532,6 +534,10 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 ifneq (,$(wildcard ../THIS_IS_MSYSGIT))
 	htmldir = share/doc/git/$(firstword $(subst -, ,$(GIT_VERSION)))/html
 	prefix =
+	# prevent conversion to Windows path on MSys1 (see
+	# http://www.mingw.org/wiki/Posix_path_conversion)
+	ETC_GITCONFIG = //etc\gitconfig
+	ETC_GITATTRIBUTES = //etc\gitattributes
 	INSTALL = /bin/install
 	EXTLIBS += /mingw/lib/libz.a
 	NO_R_TO_GCC_LINKER = YesPlease

exec_cmd.c

@@ -15,8 +15,24 @@ char *system_path(const char *path)
 #endif
 	struct strbuf d = STRBUF_INIT;
 
-	if (is_absolute_path(path))
+	if (is_absolute_path(path)) {
+#ifdef _WIN32
+		/*
+		 * On Windows (all variants), replace '/etc/' with '%PROGRAMDATA%/Git/'
+		 * (or '%ALLUSERSPROFILE%/Git' in case of Windows XP)
+		 */
+		if (!strncmp(path, "/etc/", 5)) {
+			const char *sysconfdir = getenv("PROGRAMDATA");
+			if (!sysconfdir)
+				sysconfdir = getenv("ALLUSERSPROFILE");
+			if (sysconfdir) {
+				strbuf_addf(&d, "%s/Git/%s", sysconfdir, path + 5);
+				return strbuf_detach(&d, NULL);
+			}
+		}
+#endif
 		return xstrdup(path);
+	}
 
 #ifdef RUNTIME_PREFIX
 	assert(argv0_path);