Correct the return values of the final zero-length block at EOF.

Return EOF immediately if an entry in a ZIP archive has no body.
In particular, the latter issue was causing bsdtar to emit spurious
warnings when extracting directory entries from ZIP archives.

MFC after: 3 days

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/libarchive/archive_read_support_format_zip.c b/lib/libarchive/archive_read_support_format_zip.c
index 80507bb..b07e14e 100644
--- a/lib/libarchive/archive_read_support_format_zip.c
+++ b/lib/libarchive/archive_read_support_format_zip.c
@@ -335,6 +335,10 @@ zip_read_file_header(struct archive_read *a, struct archive_entry *entry,
 	zip->entry_bytes_remaining = zip->compressed_size;
 	zip->entry_offset = 0;
 
+	/* If there's no body, force read_data() to return EOF immediately. */
+	if (zip->entry_bytes_remaining < 1)
+		zip->end_of_entry = 1;
+
 	/* Set up a more descriptive format name. */
 	sprintf(zip->format_name, "ZIP %d.%d (%s)",
 	    zip->version / 10, zip->version % 10,
@@ -422,6 +426,9 @@ archive_read_format_zip_read_data(struct archive_read *a,
 			/* End-of-entry cleanup done. */
 			zip->end_of_entry_cleanup = 1;
 		}
+		*offset = zip->entry_uncompressed_bytes_read;
+		*size = 0;
+		*buff = NULL;
 		return (ARCHIVE_EOF);
 	}