tar reader: also store condensed size of sparse files

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

3 files changed, 12 insertions, 10 deletions

diff --git a/include/tar.h b/include/tar.h
index 6fdb22d..2819740 100644
--- a/include/tar.h
+++ b/include/tar.h
@@ -72,6 +72,7 @@ typedef struct {
 	char *name;
 	char *link_target;
 	tar_sparse_data_t *sparse;
+	uint64_t sparse_size;
 	bool unknown_record;
 } tar_header_decoded_t;
 
diff --git a/lib/tar/read_header.c b/lib/tar/read_header.c
index 44a38f9..5d2a808 100644
--- a/lib/tar/read_header.c
+++ b/lib/tar/read_header.c
@@ -613,16 +613,6 @@ int read_header(int fd, tar_header_decoded_t *out)
 				goto fail;
 			continue;
 		case TAR_TYPE_GNU_SPARSE:
-			if (!(set_by_pax & PAX_SIZE)) {
-				if (read_number(hdr.tail.gnu.realsize,
-						sizeof(hdr.tail.gnu.realsize),
-						&pax_size))
-					goto fail;
-
-				out->sb.st_size = pax_size;
-				set_by_pax |= PAX_SIZE;
-			}
-
 			free_sparse_list(out->sparse);
 			out->sparse = read_gnu_old_sparse(fd, &hdr);
 			if (out->sparse == NULL)
@@ -635,6 +625,15 @@ int read_header(int fd, tar_header_decoded_t *out)
 	if (decode_header(&hdr, set_by_pax, out, version))
 		goto fail;
 
+	if (hdr.typeflag == TAR_TYPE_GNU_SPARSE) {
+		if (read_number(hdr.tail.gnu.realsize,
+				sizeof(hdr.tail.gnu.realsize), &pax_size))
+			goto fail;
+
+		out->sparse_size = out->sb.st_size;
+		out->sb.st_size = pax_size;
+	}
+
 	return 0;
 out_eof:
 	clear_header(out);
diff --git a/tests/tar_sparse_gnu.c b/tests/tar_sparse_gnu.c
index 2f2e1c5..844f7e3 100644
--- a/tests/tar_sparse_gnu.c
+++ b/tests/tar_sparse_gnu.c
@@ -40,6 +40,7 @@ int main(void)
 	assert(hdr.sb.st_uid == 01750);
 	assert(hdr.sb.st_gid == 01750);
 	assert(hdr.sb.st_size == 524288);
+	assert(hdr.sparse_size == 8192);
 	assert(strcmp(hdr.name, "input.bin") == 0);
 	assert(!hdr.unknown_record);
 
@@ -69,6 +70,7 @@ int main(void)
 	assert(hdr.sb.st_uid == 01750);
 	assert(hdr.sb.st_gid == 01750);
 	assert(hdr.sb.st_size == 2097152);
+	assert(hdr.sparse_size == 32768);
 	assert(strcmp(hdr.name, "input.bin") == 0);
 	assert(!hdr.unknown_record);