init-db: check template and repository format.

This makes init-db repository version aware.

It checks if an existing config file says the repository being
reinitialized is of a wrong version and aborts before doing
further harm.

When copying the templates, it makes sure the they are of the
right repository format version.  Otherwise the templates are
ignored with an warning message.

It copies the templates before creating the HEAD, and if the
config file is copied from the template directory, reads it,
primarily to pick up the value of core.symrefsonly.

It changes the way the result of the filemode reliability test
is written to the configuration file using git_config_set().
The test is done even if the config file was copied from the
templates.

And finally, our own repository format version is written to the
config file.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 51 insertions, 38 deletions

diff --git a/init-db.c b/init-db.c
index bd88291b0e..8195b6842e 100644
--- a/init-db.c
+++ b/init-db.c
@@ -132,6 +132,23 @@ static void copy_templates(const char *git_dir, int len, char *template_dir)
 		return;
 	}
 
+	/* Make sure that template is from the correct vintage */
+	strcpy(template_path + template_len, "config");
+	repository_format_version = 0;
+	git_config_from_file(check_repository_format_version,
+			     template_path);
+	template_path[template_len] = 0;
+
+	if (repository_format_version &&
+	    repository_format_version != GIT_REPO_VERSION) {
+		fprintf(stderr, "warning: not copying templates of "
+			"a wrong format version %d from '%s'\n",
+			repository_format_version,
+			template_dir);
+		closedir(dir);
+		return;
+	}
+
 	memcpy(path, git_dir, len);
 	path[len] = 0;
 	copy_templates_1(path, len,
@@ -140,12 +157,13 @@ static void copy_templates(const char *git_dir, int len, char *template_dir)
 	closedir(dir);
 }
 
-static void create_default_files(const char *git_dir,
-				 char *template_path)
+static void create_default_files(const char *git_dir, char *template_path)
 {
 	unsigned len = strlen(git_dir);
 	static char path[PATH_MAX];
 	unsigned char sha1[20];
+	struct stat st1;
+	char repo_version_string[10];
 
 	if (len > sizeof(path)-50)
 		die("insane git directory %s", git_dir);
@@ -164,6 +182,15 @@ static void create_default_files(const char *git_dir,
 	strcpy(path + len, "refs/tags");
 	safe_create_dir(path);
 
+	/* First copy the templates -- we might have the default
+	 * config file there, in which case we would want to read
+	 * from it after installing.
+	 */
+	path[len] = 0;
+	copy_templates(path, len, template_path);
+
+	git_config(git_default_config);
+
 	/*
 	 * Create the default symlink from ".git/HEAD" to the "master"
 	 * branch, if it does not exist yet.
@@ -173,44 +200,22 @@ static void create_default_files(const char *git_dir,
 		if (create_symref(path, "refs/heads/master") < 0)
 			exit(1);
 	}
-	path[len] = 0;
-	copy_templates(path, len, template_path);
 
-	/*
-	 * Find out if we can trust the executable bit.
-	 */
-	safe_create_dir(path);
+	/* This forces creation of new config file */
+	sprintf(repo_version_string, "%d", GIT_REPO_VERSION);
+	git_config_set("core.repositoryformatversion", repo_version_string);
+
+	path[len] = 0;
 	strcpy(path + len, "config");
-	if (access(path, R_OK) < 0) {
-		static const char contents[] =
-			"#\n"
-			"# This is the config file\n"
-			"#\n"
-			"\n"
-			"; core variables\n"
-			"[core]\n"
-			"	; Don't trust file modes\n"
-			"	filemode = false\n"
-			"\n";
-		FILE *config = fopen(path, "w");
-		struct stat st;
-
-		if (!config)
-			die("Can not write to %s?", path);
-
-		fwrite(contents, sizeof(contents)-1, 1, config);
-
-		fclose(config);
-
-		if (!lstat(path, &st)) {
-			struct stat st2;
-			if (!chmod(path, st.st_mode ^ S_IXUSR) &&
-					!lstat(path, &st2) &&
-					st.st_mode != st2.st_mode)
-				unlink(path);
-			else
-				fprintf(stderr, "Ignoring file modes\n");
-		}
+
+	/* Check filemode trustability */
+	if (!lstat(path, &st1)) {
+		struct stat st2;
+		int filemode = (!chmod(path, st1.st_mode ^ S_IXUSR) &&
+				!lstat(path, &st2) &&
+				st1.st_mode != st2.st_mode);
+		git_config_set("core.filemode",
+			       filemode ? "true" : "false");
 	}
 }
 
@@ -249,6 +254,14 @@ int main(int argc, char **argv)
 		fprintf(stderr, "defaulting to local storage area\n");
 	}
 	safe_create_dir(git_dir);
+
+	/* Check to see if the repository version is right.
+	 * Note that a newly created repository does not have
+	 * config file, so this will not fail.  What we are catching
+	 * is an attempt to reinitialize new repository with an old tool.
+	 */
+	check_repository_format();
+
 	create_default_files(git_dir, template_dir);
 
 	/*