in(x, ::StepRangeLen) fails when step is zero

[barucden]

Working on #41769, I found an error:

julia> r = StepRangeLen(3, 0, 5)
StepRangeLen(3, 0, 5)

julia> 3 in r
ERROR: DivideError: integer division error
Stacktrace:
 [1] div
   @ ./int.jl:278 [inlined]
 [2] div
   @ ./div.jl:257 [inlined]
 [3] div
   @ ./div.jl:302 [inlined]
 [4] fld
   @ ./div.jl:268 [inlined]
 [5] mod
   @ ./int.jl:270 [inlined]
 [6] in(x::Int64, r::StepRangeLen{Int64, Int64, Int64, Int64})
   @ Base ./range.jl:1346
 [7] top-level scope
   @ REPL[23]:1

This is because 3 is inside the range, and step(r) == 0 makes mod on this line fail.

Slightly related is #41402, which deals with a completely different problem, but eventually sees division error in mod. Perhaps mod should check the modulo and throw a better error too?

[martinholters]

Just inserting a step(r) == 0 before the call to mod should do the trick. Similar for the AbstractChar method ('a' in StepRangeLen('a', 0, 5) fails, too.)

[mohilkhare1708]

@martinholters I would like to work on this issue, kindly assign me this.

[martinholters]

Just go ahead, no assignment needed.