also handle floating point numbers (#26847)

base/ryu/Ryu.jl

@@ -111,7 +111,7 @@ end
 function Base.show(io::IO, x::T, forceuntyped::Bool=false, fromprint::Bool=false) where {T <: Base.IEEEFloat}
     compact = get(io, :compact, false)::Bool
     buf = Base.StringVector(neededdigits(T))
-    typed = !forceuntyped && !compact && get(io, :typeinfo, Any) != typeof(x)
+    typed = !forceuntyped && !compact && Base.nonnothing_nonmissing_typeinfo(io) != typeof(x)
     pos = writeshortest(buf, 1, x, false, false, true, -1,
         (x isa Float32 && !fromprint) ? UInt8('f') : UInt8('e'), false, UInt8('.'), typed, compact)
     write(io, resize!(buf, pos - 1))

base/show.jl

@@ -1140,14 +1140,12 @@ function show(io::IO, tn::Core.TypeName)
     print(io, ")")
 end
 
+nonnothing_nonmissing_typeinfo(io::IO) = nonmissingtype(nonnothingtype(get(io, :typeinfo, Any)))
+show(io::IO, b::Bool) = print(io, nonnothing_nonmissing_typeinfo(io) === Bool ? (b ? "1" : "0") : (b ? "true" : "false"))
 show(io::IO, ::Nothing) = print(io, "nothing")
 show(io::IO, n::Signed) = (write(io, string(n)); nothing)
 show(io::IO, n::Unsigned) = print(io, "0x", string(n, pad = sizeof(n)<<1, base = 16))
 print(io::IO, n::Unsigned) = print(io, string(n))
-function show(io::IO, b::Bool)
-    typeinfo = nonmissingtype(nonnothingtype(get(io, :typeinfo, Any)))
-    print(io, typeinfo === Bool ? (b ? "1" : "0") : (b ? "true" : "false"))
-end
 
 show(io::IO, p::Ptr) = print(io, typeof(p), " @0x$(string(UInt(p), base = 16, pad = Sys.WORD_SIZE>>2))")
 

test/show.jl

@@ -2123,6 +2123,9 @@ end
     @test_repr "Union{Bool, Nothing}[1, 0, nothing]"
 end
 
+# issue #26847
+@test_repr "Union{Missing, Float32}[1.0]"
+
 # issue #30505
 @test repr(Union{Tuple{Char}, Tuple{Char, Char}}[('a','b')]) == "Union{Tuple{Char}, Tuple{Char, Char}}[('a', 'b')]"