libdpkg: Add new pdb_deb_control parsedb flag

This will allow to distinguish when we are dealing with a possible
candidate for installation.

lib/dpkg/dpkg-db.h

@@ -302,11 +302,13 @@ enum parsedbflags {
   pdb_lax_version_parser = 040,
   /* Perform laxer parsing, used to transition to stricter parsing. */
   pdb_lax_parser = pdb_lax_version_parser,
+  /* Parse the control file from a binary .deb package. */
+  pdb_deb_control = 0100,
 
   /* Standard operations. */
   pdb_parse_status = pdb_lax_parser | pdb_weakclassification,
   pdb_parse_available = pdb_recordavailable | pdb_rejectstatus | pdb_lax_parser,
-  pdb_parse_binary = pdb_recordavailable | pdb_rejectstatus,
+  pdb_parse_binary = pdb_recordavailable | pdb_rejectstatus | pdb_deb_control,
 };
 
 const char *pkg_name_is_illegal(const char *p);