Merge recent enhancements from trunk.

FossilOrigin-Name: 4768a1066cb9c7627064d7efec44188d6755cb03

src/sqliteInt.h

@@ -1097,7 +1097,7 @@ typedef struct With With;
 ** databases may be attached.
 */
 struct Db {
-  char *zName;         /* Name of this database */
+  char *zDbSName;      /* Name of this database. (schema name, not filename) */
   Btree *pBt;          /* The B*Tree structure for this database file */
   u8 safety_level;     /* How aggressive at syncing data to disk */
   u8 bSyncSet;         /* True if "PRAGMA synchronous=N" has been run */