Ticket #924 (new bug)
Different data sets can have the same checksum
|Reported by:||Noughmad||Owned by:||janez|
The documentation data sets 'zoo.tab' and 'breast-cancer-wisconsin-cont.tab' have the same checksum, even though they contain completely different data.
In visualization widgets (for example OWScatterplot) and in the 'preprocess.scaling' module, there are many checks to see if the new data is different from the old, and do an update only in this case. However, all those checks compare the checksums instead of the actual data sets. So when changing from 'zoo' to 'breast-cancer-wisconsin-cont', the plot data is not updated.
The solution would be to ensure that checksums are unique, or to replace all test of like 'old_data.checksum() == new_data.checksum()' with 'old_data.checksum() == new_data.checksum() and old_data == new_data'. It would probably also be possible to override the eq operator of ExampleTable so it would first compare the checksum, and then compare the data only if the checksums are the same.