C# Class SIL.FieldWorks.FixData.SequenceFixer

This class contains code to fix situations where merges have resulted in sequences that are empty and shouldn't be. In normal operation, FDO takes care of these situations automatically, but in a Send/Receive situation FDO might not 'know' that one user deleted a sequence element while another user deleted the other with the result on merging that now both are gone. Usually the required fix is to delete the parent that holds the sequence. This class also contains code to fix situations where merges have resulted in a Segment being deleted and dangling references still exist in TextTag objects and ConstChartWordGroup objects. In normal operation, FDO takes care of these situations automatically, but in a Send/Receive situation FDO might not 'know' that one user deleted a Segment element while another user created references to it, with the result on merging that now references to a non-existent Segment exist. The Original Fixer will delete the dangling references to the Segment, but the TextTag and WordGroup objects should not have empty Begin or EndSegment references. If both Begin and EndSegment belong to missing Segments, we delete the object in question. If only one belongs to a missing Segment, we replace its reference with a reference to the other Segment. This class also contains code to fix situations where a LexReference object is found to only contain one Target. The LexReference object will be deleted. There may have been bugs in the past which allowed this sort of thing to occur. They seem to have been fixed, but Send/Receive could conceivably generate such situations too.