Segfault when solving without setup!

[migarstka]

The following code produces a segfault in Julia:

using OSQP
model = OSQP.Model()
result = OSQP.solve!(model)

results in:

ERROR in osqp_solve: Solver workspace not initialized.

signal (11): Segmentation fault: 11
in expression starting at REPL[3]:1
getproperty at ./Base.jl:20 [inlined]
solve! at /Users/Micha/.julia/packages/OSQP/BU4WO/src/interface.jl:173
solve! at /Users/Micha/.julia/packages/OSQP/BU4WO/src/interface.jl:171
jl_apply at /Users/sabae/buildbot/worker/package_macos64/build/src/./julia.h:1631 [inlined]
do_call at /Users/sabae/buildbot/worker/package_macos64/build/src/interpreter.c:328
eval_body at /Users/sabae/buildbot/worker/package_macos64/build/src/interpreter.c:0
jl_interpret_toplevel_thunk_callback at /Users/sabae/buildbot/worker/package_macos64/build/src/interpreter.c:888
unknown function (ip: 0xfffffffffffffffe)
unknown function (ip: 0x131322a0f)
unknown function (ip: 0x0)
jl_interpret_toplevel_thunk at /Users/sabae/buildbot/worker/package_macos64/build/src/interpreter.c:897
jl_toplevel_eval_flex at /Users/sabae/buildbot/worker/package_macos64/build/src/toplevel.c:814
jl_toplevel_eval_flex at /Users/sabae/buildbot/worker/package_macos64/build/src/toplevel.c:764
jl_toplevel_eval at /Users/sabae/buildbot/worker/package_macos64/build/src/toplevel.c:823 [inlined]
jl_toplevel_eval_in at /Users/sabae/buildbot/worker/package_macos64/build/src/toplevel.c:843
eval at /Applications/Julia-1.3.app/Contents/Resources/julia/lib/julia/sys.dylib (unknown line)
eval_user_input at /Applications/Julia-1.3.app/Contents/Resources/julia/share/julia/stdlib/v1.3/REPL/src/REPL.jl:86
run_backend at /Users/Micha/.julia/packages/Revise/SefCg/src/Revise.jl:1042
#85 at ./task.jl:333
jl_apply at /Users/sabae/buildbot/worker/package_macos64/build/src/./julia.h:1631 [inlined]
start_task at /Users/sabae/buildbot/worker/package_macos64/build/src/task.c:659
Allocations: 33366879 (Pool: 33359381; Big: 7498); GC: 32
Segmentation fault: 11

This should be easy to fix.
I will make a PR to fix this (hopefully) sometime this week.

[bstellato]

Thanks a lot Michael! It would be very helpful to have a PR. It is an error correctly reported from C but not handled properly from Julia. I think Julia is trying to access memory that was not allocated.