Merge pull request #21756 from JuliaLang/teh/linspace_promotion

Fix a promotion failure with linspace

Author: timholy

base/range.jl

@@ -238,6 +238,7 @@ julia> linspace(1.3,2.9,9)
 ```
 """
 linspace(start, stop, len::Real=50) = linspace(promote_noncircular(start, stop)..., Int(len))
+linspace(start::T, stop::T, len::Real=50) where {T} = linspace(start, stop, Int(len))
 
 linspace(start::Real, stop::Real, len::Integer) = linspace(promote(start, stop)..., len)
 linspace(start::T, stop::T, len::Integer) where {T<:Integer} = linspace(Float64, start, stop, len, 1)

test/ranges.jl

@@ -25,6 +25,7 @@ L64 = @inferred(linspace(Int64(1), Int64(4), 4))
 @test L32[2] == 2 && L64[2] == 2
 @test L32[3] == 3 && L64[3] == 3
 @test L32[4] == 4 && L64[4] == 4
+@test @inferred(linspace(1.0, 2.0, 2.0f0)) === linspace(1.0, 2.0, 2)
 
 r = 5:-1:1
 @test r[1]==5