Loosen searchsorted* index type (fixes JuliaLang#30763)

* Might also address JuliaLang#31618
* Types of start and stop indicies are still restricted to
  Union{Int32,Int64} and must be the same

base/sort.jl

@@ -170,10 +170,10 @@ partialsort(v::AbstractVector, k::Union{Int,OrdinalRange}; kws...) =
 
 # index of the first value of vector a that is greater than or equal to x;
 # returns length(v)+1 if x is greater than all values in v.
-function searchsortedfirst(v::AbstractVector, x, lo::Int, hi::Int, o::Ordering)
-    lo = lo-1
-    hi = hi+1
-    @inbounds while lo < hi-1
+function searchsortedfirst(v::AbstractVector, x, lo::INT, hi::INT, o::Ordering) where INT<:Union{Int32,Int64}
+    lo = lo-INT(1)
+    hi = hi+INT(1)
+    @inbounds while lo < hi-INT(1)
         m = (lo+hi)>>>1
         if lt(o, v[m], x)
             lo = m
@@ -186,10 +186,10 @@ end
 
 # index of the last value of vector a that is less than or equal to x;
 # returns 0 if x is less than all values of v.
-function searchsortedlast(v::AbstractVector, x, lo::Int, hi::Int, o::Ordering)
-    lo = lo-1
-    hi = hi+1
-    @inbounds while lo < hi-1
+function searchsortedlast(v::AbstractVector, x, lo::INT, hi::INT, o::Ordering) where INT<:Union{Int32,Int64}
+    lo = lo-INT(1)
+    hi = hi+INT(1)
+    @inbounds while lo < hi-INT(1)
         m = (lo+hi)>>>1
         if lt(o, x, v[m])
             hi = m
@@ -203,10 +203,10 @@ end
 # returns the range of indices of v equal to x
 # if v does not contain x, returns a 0-length range
 # indicating the insertion point of x
-function searchsorted(v::AbstractVector, x, ilo::Int, ihi::Int, o::Ordering)
-    lo = ilo-1
-    hi = ihi+1
-    @inbounds while lo < hi-1
+function searchsorted(v::AbstractVector, x, ilo::INT, ihi::INT, o::Ordering) where INT<:Union{Int32,Int64}
+    lo = ilo-INT(1)
+    hi = ihi+INT(1)
+    @inbounds while lo < hi-INT(1)
         m = (lo+hi)>>>1
         if lt(o, v[m], x)
             lo = m

test/sorting.jl

@@ -1,7 +1,10 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
+module SortingTests
+
 using Base.Order: Forward
 using Random
+using Test
 
 @test sort([2,3,1]) == [1,2,3]
 @test sort([2,3,1], rev=true) == [3,2,1]
@@ -371,3 +374,29 @@ end
 end
 # https://discourse.julialang.org/t/sorting-big-int-with-v-0-6/1241
 @test sort([big(3), big(2)]) == [big(2), big(3)]
+
+@testset "issue #30763" begin
+    for INT in [:Int32, :Int64]
+        @eval begin
+            struct T_30763{T}
+                n::T
+            end
+
+            Base.zero(::T_30763{$INT}) = T_30763{$INT}(0)
+            Base.convert(::Type{T_30763{$INT}}, n::Integer) = T_30763{$INT}($INT(n))
+            Base.isless(a::T_30763{$INT}, b::T_30763{$INT}) = isless(a.n, b.n)
+            Base.:(-)(a::T_30763{$INT}, b::T_30763{$INT}) = T_30763{$INT}(a.n - b.n)
+            Base.:(+)(a::T_30763{$INT}, b::T_30763{$INT}) = T_30763{$INT}(a.n + b.n)
+            Base.:(*)(n::Integer, a::T_30763{$INT}) = T_30763{$INT}(n * a.n)
+            Base.rem(a::T_30763{$INT}, b::T_30763{$INT}) = T_30763{$INT}(rem(a.n, b.n))
+
+            # The important part of this test is that the return type of length might be different from Int
+            Base.length(r::StepRange{T_30763{$INT},T_30763{$INT}}) = $INT((last(r).n - first(r).n) ÷ step(r).n)
+        end
+    end
+
+    @test searchsorted(T_30763{Int32}(1):T_30763{Int32}(3), T_30763{Int32}(2)) == 2:2
+    @test searchsorted(T_30763{Int64}(1):T_30763{Int64}(3), T_30763{Int64}(2)) == 2:2
+end
+
+end