valgrind error in CU::isGBiIdxCoded

[fbossen]

with commit d403235c

EncoderApp -c cfg/per-sequence/BQSquare.cfg -c cfg/encoder_randomaccess_vtm.cfg -dph 1

==46870== Conditional jump or move depends on uninitialised value(s)
==46870==    at 0x1001190F3: CU::isGBiIdxCoded(CodingUnit const&) (UnitTools.cpp:5626)
==46870==    by 0x10016BF2B: CABACWriter::cu_pred_data(CodingUnit const&) (CABACWriter.cpp:918)
==46870==    by 0x1001FD58C: InterSearch::xGetSymbolFracBitsInter(CodingStructure&, Partitioner&) (InterSearch.cpp:7258)
==46870==    by 0x1001FC11A: InterSearch::encodeResAndCalcRdInterCU(CodingStructure&, Partitioner&, bool const&, bool, bool) (InterSearch.cpp:7114)
==46870==    by 0x100194A3D: EncCu::xEncodeInterResidual(CodingStructure*&, CodingStructure*&, Partitioner&, EncTestMode const&, int, CodingStructure*, bool*, double*) (EncCu.cpp:4334)
==46870==    by 0x100188322: EncCu::xCheckRDCostAffineMerge2Nx2N(CodingStructure*&, CodingStructure*&, Partitioner&, EncTestMode const&) (EncCu.cpp:3214)
==46870==    by 0x1001838D4: EncCu::xCompressCU(CodingStructure*&, CodingStructure*&, Partitioner&, LutMotionCand*&, LutMotionCand*&) (EncCu.cpp:833)
==46870==    by 0x1001827D7: EncCu::compressCtu(CodingStructure&, UnitArea const&, unsigned int, int const*, int const*) (EncCu.cpp:445)
==46870==    by 0x1001DAC74: EncSlice::encodeCtus(Picture*, bool, bool, unsigned int, unsigned int, EncLib*) (EncSlice.cpp:1673)
==46870==    by 0x1001D996C: EncSlice::compressSlice(Picture*, bool, bool) (EncSlice.cpp:1386)
==46870==    by 0x10019F8F5: EncGOP::compressGOP(int, int, std::__1::list<Picture*, std::__1::allocator<Picture*> >&, std::__1::list<UnitBuf<short>*, std::__1::allocator<UnitBuf<short>*> >&, bool, bool, InputColourSpaceConversion, bool, bool) (EncGOP.cpp:2327)

The line with the reported error is:

  if( cu.firstPU->interDir == 3 && !cu.firstPU->mergeFlag )

[fbossen]

Issue still present in commit 2411a1a (Feb 15)

[yuchi]

This issue is resulted from uninitialized mrgCtx.interDirNeighbours[count] in the function getInterMergeSubPuMvpCand().

A fix is provided in
​https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM/merge_requests/313