Attempting to use ctdbAlterTable to alter segmented files that did not actually have any segments other than the "host" was failing with CTDDRET_NOTSUPPORTED. The logic has been changed to allow such files to be altered. The alter table code also converts the table into a non-segmented table. It can later be converted back to a segmented file if necessary. There has been no change in the behavior of ctdbAlterTable with segmented files that have segments in addition to "host."