archive: reorder option parsing and config reading

The archive command does three things during its
initialization phase:

  1. parse command-line options

  2. setup the git directory

  3. read config

During phase (1), if we see any options that do not require
a git directory (like "--list"), we handle them immediately
and exit, making it safe to abort step (2) if we are not in
a git directory.

Step (3) must come after step (2), since the git directory
may influence configuration.  However, this leaves no
possibility of configuration from step (3) impacting the
command-line options in step (1) (which is useful, for
example, for supporting user-configurable output formats).

Instead, let's reorder this to:

  1. setup the git directory, if it exists

  2. read config

  3. parse command-line options

  4. if we are not in a git repository, die

This should have the same external behavior, but puts
configuration before command-line parsing.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

archive.c

@@ -387,17 +387,27 @@ static int parse_archive_args(int argc, const char **argv,
 int write_archive(int argc, const char **argv, const char *prefix,
 		int setup_prefix)
 {
+	int nongit = 0;
 	const struct archiver *ar = NULL;
 	struct archiver_args args;
 
-	argc = parse_archive_args(argc, argv, &ar, &args);
 	if (setup_prefix && prefix == NULL)
-		prefix = setup_git_directory();
+		prefix = setup_git_directory_gently(&nongit);
+
+	git_config(git_default_config, NULL);
+
+	argc = parse_archive_args(argc, argv, &ar, &args);
+	if (nongit) {
+		/*
+		 * We know this will die() with an error, so we could just
+		 * die ourselves; but its error message will be more specific
+		 * than what we could write here.
+		 */
+		setup_git_directory();
+	}
 
 	parse_treeish_arg(argv, &args, prefix);
 	parse_pathspec_arg(argv + 1, &args);
 
-	git_config(git_default_config, NULL);
-
 	return ar->write_archive(&args);
 }