archive: initialize archivers earlier

Initialize archivers as soon as possible when running git-archive.
Various non-obvious behavior depends on having the archivers
initialized, such as determining the desired archival format from the
provided filename.

Since 08716b3c11 ("archive: refactor file extension format-guessing",
2011-06-21), archive_format_from_filename() has used the registered
archivers to match filenames (provided via --output) to archival
formats. However, when git-archive is executed with --remote, format
detection happens before the archivers have been registered. This causes
archives from remotes to always be generated as TAR files, regardless of
the actual filename (unless an explicit --format is provided).

This patch fixes that behavior; archival format is determined properly
from the output filename, even when --remote is used.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

archive.c

@@ -29,6 +29,12 @@ void register_archiver(struct archiver *ar)
 	archivers[nr_archivers++] = ar;
 }
 
+void init_archivers(void)
+{
+	init_tar_archiver();
+	init_zip_archiver();
+}
+
 static void format_subst(const struct commit *commit,
                          const char *src, size_t len,
                          struct strbuf *buf)
@@ -531,9 +537,6 @@ int write_archive(int argc, const char **argv, const char *prefix,
 	git_config_get_bool("uploadarchive.allowunreachable", &remote_allow_unreachable);
 	git_config(git_default_config, NULL);
 
-	init_tar_archiver();
-	init_zip_archiver();
-
 	args.repo = repo;
 	argc = parse_archive_args(argc, argv, &ar, &args, name_hint, remote);
 	if (!startup_info->have_repository) {

archive.h

@@ -43,6 +43,7 @@ extern void register_archiver(struct archiver *);
 
 extern void init_tar_archiver(void);
 extern void init_zip_archiver(void);
+extern void init_archivers(void);
 
 typedef int (*write_archive_entry_fn_t)(struct archiver_args *args,
 					const struct object_id *oid,

builtin/archive.c

@@ -97,6 +97,8 @@ int cmd_archive(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, local_opts, NULL,
 			     PARSE_OPT_KEEP_ALL);
 
+	init_archivers();
+
 	if (output)
 		create_output_file(output);
 

builtin/upload-archive.c

@@ -28,6 +28,8 @@ int cmd_upload_archive_writer(int argc, const char **argv, const char *prefix)
 	if (!enter_repo(argv[1], 0))
 		die("'%s' does not appear to be a git repository", argv[1]);
 
+	init_archivers();
+
 	/* put received options in sent_argv[] */
 	argv_array_push(&sent_argv, "git-upload-archive");
 	for (;;) {

t/t5000-tar-tree.sh

@@ -206,6 +206,12 @@ test_expect_success 'git archive with --output, override inferred format' '
 	test_cmp_bin b.tar d4.zip
 '
 
+test_expect_success GZIP 'git archive with --output and --remote creates .tgz' '
+	git archive --output=d5.tgz --remote=. HEAD &&
+	gzip -d -c <d5.tgz >d5.tar &&
+	test_cmp_bin b.tar d5.tar
+'
+
 test_expect_success 'git archive --list outside of a git repo' '
 	nongit git archive --list
 '

t/t5003-archive-zip.sh

@@ -158,11 +158,16 @@ test_expect_success 'git archive --format=zip with --output' \
     'git archive --format=zip --output=d2.zip HEAD &&
     test_cmp_bin d.zip d2.zip'
 
-test_expect_success 'git archive with --output, inferring format' '
+test_expect_success 'git archive with --output, inferring format (local)' '
 	git archive --output=d3.zip HEAD &&
 	test_cmp_bin d.zip d3.zip
 '
 
+test_expect_success 'git archive with --output, inferring format (remote)' '
+	git archive --remote=. --output=d4.zip HEAD &&
+	test_cmp_bin d.zip d4.zip
+'
+
 test_expect_success \
     'git archive --format=zip with prefix' \
     'git archive --format=zip --prefix=prefix/ HEAD >e.zip'