Allow empty packages, i.e. packages not containing any files

Signed-off-by: David Oberhollenzer <goliath@infraroot.at>

include/pkgio.h

@@ -13,6 +13,6 @@ enum {
 
 int pkg_unpack(int rootfd, int flags, pkg_reader_t *rd);
 
-image_entry_t *image_entry_list_from_package(pkg_reader_t *pkg);
+int image_entry_list_from_package(pkg_reader_t *pkg, image_entry_t ** list);
 
 #endif /* PKGIO_H */

main/cmd/dump/dump.c

@@ -75,11 +75,10 @@ static int cmd_dump(int argc, char **argv)
 			goto out;
 	}
 
-	list = image_entry_list_from_package(rd);
-	if (list == NULL)
+	if (image_entry_list_from_package(rd, &list))
 		goto out;
 
-	if (flags & DUMP_TOC) {
+	if (flags & DUMP_TOC && list != NULL) {
 		if (dump_toc(list, root, format))
 			goto out;
 	}

main/cmd/install/install.c

@@ -58,13 +58,12 @@ static int list_files(int repofd, const char *rootdir, TOC_FORMAT format,
 		if (rd == NULL)
 			return -1;
 
-		toc = image_entry_list_from_package(rd);
-		if (toc == NULL) {
+		if (image_entry_list_from_package(rd, &toc)) {
 			pkg_reader_close(rd);
 			return -1;
 		}
 
-		if (dump_toc(toc, rootdir, format)) {
+		if (toc != NULL && dump_toc(toc, rootdir, format)) {
 			image_entry_free_list(toc);
 			pkg_reader_close(rd);
 			return -1;

main/cmd/pack/filelist.c

@@ -258,27 +258,49 @@ static const keyword_handler_t line_hooks[] = {
 
 #define NUM_LINE_HOOKS (sizeof(line_hooks) / sizeof(line_hooks[0]))
 
-image_entry_t *filelist_read(const char *filename)
+static int alloc_file_ids(image_entry_t *list)
+{
+	image_entry_t *ent;
+	uint64_t file_id = 0;
+
+	for (ent = list; ent != NULL; ent = ent->next) {
+		if (!S_ISREG(ent->mode))
+			continue;
+
+		if (file_id > 0x00000000FFFFFFFFUL) {
+			fprintf(stderr, "too many input files\n");
+			return -1;
+		}
+
+		ent->data.file.id = file_id++;
+	}
+
+	return 0;
+}
+
+int filelist_read(const char *filename, image_entry_t **out)
 {
 	image_entry_t *list = NULL;
 	input_file_t f;
 
 	if (open_file(&f, filename))
-		return NULL;
+		return -1;
 
 	if (process_file(&f, line_hooks, NUM_LINE_HOOKS, &list))
 		goto fail;
 
-	if (list == NULL) {
-		fprintf(stderr, "%s: does not contain any entries\n",
-			f.filename);
+	if (list != NULL) {
+		list = image_entry_sort(list);
+
+		if (alloc_file_ids(list))
 			goto fail;
 	}
 
 	cleanup_file(&f);
-	return list;
+	*out = list;
+	return 0;
 fail:
 	cleanup_file(&f);
 	image_entry_free_list(list);
-	return NULL;
+	return -1;
 }

main/cmd/pack/pack.c

@@ -40,26 +40,6 @@ static compressor_t *try_get_compressor(const char *name)
 	return cmp;
 }
 
-static int alloc_file_ids(image_entry_t *list)
-{
-	image_entry_t *ent;
-	uint64_t file_id = 0;
-
-	for (ent = list; ent != NULL; ent = ent->next) {
-		if (!S_ISREG(ent->mode))
-			continue;
-
-		if (file_id > 0x00000000FFFFFFFFUL) {
-			fprintf(stderr, "too many input files\n");
-			return -1;
-		}
-
-		ent->data.file.id = file_id++;
-	}
-
-	return 0;
-}
-
 static pkg_writer_t *open_writer(pkg_desc_t *desc, const char *repodir)
 {
 	char *path;
@@ -77,7 +57,7 @@ static int cmd_pack(int argc, char **argv)
 {
 	const char *filelist = NULL, *repodir = NULL, *descfile = NULL;
 	compressor_t *cmp_toc, *cmp_files;
-	image_entry_t *list;
+	image_entry_t *list = NULL;
 	pkg_writer_t *wr;
 	pkg_desc_t desc;
 	int i;
@@ -133,27 +113,15 @@ static int cmd_pack(int argc, char **argv)
 		return EXIT_FAILURE;
 	}
 
-	if (filelist == NULL) {
-		fputs("missing argument: input file list\n", stderr);
-		tell_read_help(argv[0]);
-		return EXIT_FAILURE;
-	}
-
 	if (optind < argc)
 		fputs("warning: ignoring extra arguments\n", stderr);
 
 	if (desc_read(descfile, &desc))
 		return EXIT_FAILURE;
 
-	list = filelist_read(filelist);
-	if (list == NULL)
+	if (filelist != NULL && filelist_read(filelist, &list))
 		goto fail_desc;
 
-	list = image_entry_sort(list);
-
-	if (alloc_file_ids(list))
-		goto fail_fp;
-
 	wr = open_writer(&desc, repodir);
 	if (wr == NULL)
 		goto fail_fp;
@@ -161,11 +129,13 @@ static int cmd_pack(int argc, char **argv)
 	if (write_header_data(wr, &desc))
 		goto fail;
 
+	if (list != NULL) {
 		if (write_toc(wr, list, cmp_toc))
 			goto fail;
 
 		if (write_files(wr, list, cmp_files))
 			goto fail;
+	}
 
 	pkg_writer_close(wr);
 	image_entry_free_list(list);

main/cmd/pack/pack.h

@@ -42,7 +42,7 @@ int filelist_mkslink(input_file_t *f, void *obj);
 
 int filelist_mkfile(input_file_t *f, void *obj);
 
-image_entry_t *filelist_read(const char *filename);
+int filelist_read(const char *filename, image_entry_t **out);
 
 int write_toc(pkg_writer_t *wr, image_entry_t *list, compressor_t *cmp);
 

main/pkg_unpack.c

@@ -198,13 +198,15 @@ int pkg_unpack(int rootfd, int flags, pkg_reader_t *rd)
 	record_t *hdr;
 	int ret;
 
-	list = image_entry_list_from_package(rd);
-	if (list == NULL)
+	if (image_entry_list_from_package(rd, &list))
 		return -1;
 
 	if (pkg_reader_rewind(rd))
 		goto fail;
 
+	if (list == NULL)
+		return 0;
+
 	if (create_hierarchy(rootfd, list, flags))
 		goto fail;
 

main/pkgio_rd_image_entry.c

@@ -83,20 +83,28 @@ fail_trunc:
 	return -1;
 }
 
-image_entry_t *image_entry_list_from_package(pkg_reader_t *pkg)
+int image_entry_list_from_package(pkg_reader_t *pkg, image_entry_t **out)
 {
 	image_entry_t *list = NULL, *end = NULL, *imgent;
 	toc_entry_t ent;
 	record_t *hdr;
 	ssize_t ret;
 	char *path;
+	int status;
 
 	if (pkg_reader_rewind(pkg))
-		return NULL;
+		return -1;
 
 	do {
-		if (pkg_reader_get_next_record(pkg) <= 0)
-			return NULL;
+		status = pkg_reader_get_next_record(pkg);
+
+		if (status == 0) {
+			*out = NULL;
+			return 0;
+		}
+
+		if (status < 0)
+			return -1;
 
 		hdr = pkg_reader_current_record_header(pkg);
 	} while (hdr->magic != PKG_MAGIC_TOC);
@@ -170,7 +178,8 @@ image_entry_t *image_entry_list_from_package(pkg_reader_t *pkg)
 			goto fail_multi;
 	}
 
-	return image_entry_sort(list);
+	*out = image_entry_sort(list);
+	return 0;
 fail_oom:
 	fputs("out of memory\n", stderr);
 	goto fail;
@@ -184,5 +193,5 @@ fail_multi:
 	goto fail;
 fail:
 	image_entry_free_list(list);
-	return NULL;
+	return -1;
 }