[PATCH v3 2/5] Add the NOTMUCH_FEATURE_INDEXED_MIMETYPES database feature

[Todd]

---
 lib/database-private.h | 15 ++++++++++++---
 lib/database.cc        | 10 ++++++++--
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/lib/database-private.h b/lib/database-private.h
index 15e03cc..6d6fa2c 100644
--- a/lib/database-private.h
+++ b/lib/database-private.h
@@ -92,6 +92,14 @@ enum _notmuch_features {
      *
      * Introduced: version 3. */
     NOTMUCH_FEATURE_GHOSTS = 1 << 4,
+
+
+    /* If set, then the database was created after the introduction of
+     * indexed mime types. If unset, then the database may contain a
+     * mixture of messages with indexed and non-indexed mime types.
+     *
+     * Introduced: version 3. */
+    NOTMUCH_FEATURE_INDEXED_MIMETYPES = 1 << 5,
 };
 
 /* In C++, a named enum is its own type, so define bitwise operators
@@ -161,9 +169,10 @@ struct _notmuch_database {
 
 /* Current database features.  If any of these are missing from a
  * database, request an upgrade.
- * NOTMUCH_FEATURE_FROM_SUBJECT_ID_VALUES is not included because
- * upgrade doesn't currently introduce the feature (though brand new
- * databases will have it). */
+ * NOTMUCH_FEATURE_FROM_SUBJECT_ID_VALUES and
+ * NOTMUCH_FEATURE_INDEXED_MIMETYPES are not included because upgrade
+ * doesn't currently introduce the features (though brand new databases
+ * will have it). */
 #define NOTMUCH_FEATURES_CURRENT \
     (NOTMUCH_FEATURE_FILE_TERMS | NOTMUCH_FEATURE_DIRECTORY_DOCS | \
      NOTMUCH_FEATURE_BOOL_FOLDER | NOTMUCH_FEATURE_GHOSTS)
diff --git a/lib/database.cc b/lib/database.cc
index 3601f9d..0d2c417 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -304,6 +304,11 @@ static const struct {
       "exact folder:/path: search", "rw" },
     { NOTMUCH_FEATURE_GHOSTS,
       "mail documents for missing messages", "w"},
+    /* Knowledge of the index mime-types are not required for reading
+     * a database because a reader will just be unable to query
+     * them. */
+    { NOTMUCH_FEATURE_INDEXED_MIMETYPES,
+      "indexed MIME types", "w"},
 };
 
 const char *
@@ -646,9 +651,10 @@ notmuch_database_create (const char *path, notmuch_database_t **database)
     if (status)
 	goto DONE;
 
-    /* Upgrade doesn't add this feature to existing databases, but new
-     * databases have it. */
+    /* Upgrade doesn't add these feature to existing databases, but
+     * new databases have them. */
     notmuch->features |= NOTMUCH_FEATURE_FROM_SUBJECT_ID_VALUES;
+    notmuch->features |= NOTMUCH_FEATURE_INDEXED_MIMETYPES;
 
     status = notmuch_database_upgrade (notmuch, NULL, NULL);
     if (status) {
-- 
1.9.1