libziparchive: add zipinfo(1).

Useful for debugging and hermetic builds. (Various places in the build
check to see that a file was stored uncompressed.)

Test: manual
Change-Id: I127e5689cd493ab06739b765beed50912dc9cc1d
diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc
index 3a552d8..caf8fae 100644
--- a/libziparchive/zip_archive.cc
+++ b/libziparchive/zip_archive.cc
@@ -478,6 +478,13 @@
   return OpenArchiveInternal(archive, debug_file_name);
 }
 
+ZipArchiveInfo GetArchiveInfo(ZipArchiveHandle archive) {
+  ZipArchiveInfo result;
+  result.archive_size = archive->mapped_zip.GetFileLength();
+  result.entry_count = archive->num_entries;
+  return result;
+}
+
 /*
  * Close a ZipArchive, closing the file and freeing the contents.
  */
@@ -614,12 +621,17 @@
   }
 
   // 4.4.2.1: the upper byte of `version_made_by` gives the source OS. Unix is 3.
-  if ((cdr->version_made_by >> 8) == 3) {
+  data->version_made_by = cdr->version_made_by;
+  if ((data->version_made_by >> 8) == 3) {
     data->unix_mode = (cdr->external_file_attributes >> 16) & 0xffff;
   } else {
     data->unix_mode = 0777;
   }
 
+  // 4.4.14: the lowest bit of the internal file attributes field indicates text.
+  // Currently only needed to implement zipinfo.
+  data->is_text = (cdr->internal_file_attributes & 1);
+
   // Check that the local file header name matches the declared
   // name in the central directory.
   if (lfh->file_name_length != nameLen) {