Avoid duplicate entries in MPM list when multiref is used

Fix provided by zhi.a.zhang@ericsson.com Fixes #100

It looks like the existing code is aligned with what is currently integrated in the spec text.

@ksuehring what text are you referring to? L1001v2 doesn't seem to have 6 MPMs

I got a copy of the current state from Ben, I'll forward.

@ksuehring Thanks. Agree that the text currently matches the software. Text looks very drafty and buggy though :-) For instance point 5 in section 8.2.2 doesn't seem to have been updated for 6 MPMs. Also the use of intra_luma_mpm_remainder doesn't make sense if there are duplicated entries in the MPM list

Had the same feeling.

@bossen @ksuehring FYI, I believe the instance point 5 in section 8.2.2 has been updated for 6 MPMs in the latest text.

It looks in the current MPM coding, it is correct that there could be duplicate MPMs derived for non-zero reference line. The SW change proposed in this merge request fixes this issue.

merged

mentioned in commit 199dd053