Search is treating an undefined omega angles as if equal to zero when filtering.

[aebrer]

From OSL:

If I create a new search, then set the number of residues to 1, resolution to 1.5, and ask for residues with omega near zero (with "<=-40,>=40" and a minus sign) and execute the search I get 4354 hits. Going to the "Browse" page I see that many of the hits have omega equal to "-" which means it cannot be calculated.
Omega cannot be calculated for these residues because they are at the end of the chain and there is no N+1 or Ca+1 atoms. Splicer is, apparently, flagging these angles as undefined since the Browser page is showing their values as "-", which is correct. These residues should not be listed as hits because their undefined omega does not lie between -40 and +40 degrees.
If I change the search to two residues, but do not specify any selection criteria for the second one, other than its simple existence, the search returns the more plausible 1421 hits.
As you can see, this is a significant problem because the rate of occurrence of residues with omega near zero is much smaller than the rate of residues at the end of chains.
I expect the same error is affecting other angles that span atoms from two residues.