Large memory leak in kinsol nonlinear solver

[RSchiemann]

When running a simulation of a "large" (8000 equations, 4000 of which are trivial) model with -nls=kinsol, the memory allocated by the simulation process grows very large. On a machine with 16 GB, the machine runs out of memory if simulation is large enough. I observed memory accumulation rates of 40 MB/s, which is a lot.

I use the following setup:
OMEdit v1.14.0-dev-26461-gf6f5727072 (64-bit)
Connected to v1.14.0-dev-26461-gf6f5727072 (64-bit)
Connected to OMSimulator v2.1.0-dev-103-g9e04b31-mingw

I don't use the new NF.

The simulation is called with the following arguments (I removed unnecessary paths and replaced them by [...]):
model.exe -port=59221 -logFormat=xmltcp -override=startTime=0,stopTime=5000,stepSize=500,tolerance=0.0001,solver=dassl,outputFormat=mat,variableFilter=.* -r=[...]model_res.mat -jacobian=symbolical -nls=kinsol -w -lv=LOG_DASSL,LOG_STATS,LOG_STATS_V -inputPath=[...]/AppData/Local/Temp/OpenModelica/OMEdit/Outotec.PlantModels.PelletPlant14 -outputPath=[...]/AppData/Local/Temp/OpenModelica/OMEdit/Outotec.PlantModels.PelletPlant14

I see great similarity to this old ticket:
https://trac.openmodelica.org/OpenModelica/ticket/3646

When I use the default solver (which is much, much slower than kinsol for my model), memory usage remains practically constant.