lib: Consolidate checks for read-only database.

Previously, many checks were deep in the library just before a cast
operation. These have now been replaced with internal errors and new
checks have instead been added at the beginning of all top-levelentry
points requiring a read-write database.

The new checks now also use a single function for checking and
printing the error message. This will give us a convenient location to
extend the check, (such as based on database version as well).

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h
index 8b582640..4eb82619 100644
--- a/lib/notmuch-private.h
+++ b/lib/notmuch-private.h
@@ -151,6 +151,9 @@ typedef enum _notmuch_private_status {
 const char *
 _find_prefix (const char *name);
 
+notmuch_status_t
+_notmuch_database_ensure_writable (notmuch_database_t *notmuch);
+
 const char *
 _notmuch_database_relative_path (notmuch_database_t *notmuch,
 				 const char *path);