Bug 406422 - Globally decay adaptive input history to allow for new entries. r=dietrich

toolkit/components/places/src/nsNavHistoryExpire.cpp

@@ -976,7 +976,7 @@ nsNavHistoryExpire::ExpireAnnotationsParanoid(mozIStorageConnection* aConnection
 
 // nsNavHistoryExpire::ExpireInputHistoryParanoid
 //
-//    Deletes dangling input history
+//    Deletes dangling input history, decay potentially unused entries
 
 nsresult
 nsNavHistoryExpire::ExpireInputHistoryParanoid(mozIStorageConnection* aConnection)
@@ -989,6 +989,13 @@ nsNavHistoryExpire::ExpireInputHistoryParanoid(mozIStorageConnection* aConnectio
       "WHERE h.id IS NULL)"));
   NS_ENSURE_SUCCESS(rv, rv);
 
+  // Decay potentially unused entries (e.g. those that are at 1) to allow
+  // better chances for new entries that will start at 1
+  rv = aConnection->ExecuteSimpleSQL(NS_LITERAL_CSTRING(
+    "UPDATE moz_inputhistory "
+    "SET use_count = use_count * .9"));
+  NS_ENSURE_SUCCESS(rv, rv);
+
   return NS_OK;
 }