Fix and test an overflow issue in searchsorted (#56464)

And remove `searchsorted` special cases for offset arrays in tests that
had the impact of bypassing actually testing `searchsorted` behavior on
offset arrays

To be clear, after this bugfix the function is still broken, just a little bit less so.

base/sort.jl

@@ -231,8 +231,8 @@ function searchsorted(v::AbstractVector, x, ilo::T, ihi::T, o::Ordering)::UnitRa
         elseif lt(o, x, v[m])
             hi = m
         else
-            a = searchsortedfirst(v, x, max(lo,ilo), m, o)
-            b = searchsortedlast(v, x, m, min(hi,ihi), o)
+            a = searchsortedfirst(v, x, lo+u, m, o)
+            b = searchsortedlast(v, x, m, hi-u, o)
             return a : b
         end
     end

test/sorting.jl

@@ -581,6 +581,10 @@ end
     @test searchsortedfirst(o, 1.5) == 0
     @test searchsortedlast(o, 0) == firstindex(o) - 1
     @test searchsortedlast(o, 1.5) == -1
+
+    # Issue #56457
+    o2 = OffsetArray([2,2,3], typemax(Int)-3);
+    @test searchsorted(o2, 2) == firstindex(o2):firstindex(o2)+1
 end
 
 function adaptive_sort_test(v; trusted=InsertionSort, kw...)

test/testhelpers/OffsetArrays.jl

@@ -821,17 +821,6 @@ centered(A::AbstractArray, cp::Dims=center(A)) = OffsetArray(A, .-cp)
 
 centered(A::AbstractArray, i::CartesianIndex) = centered(A, Tuple(i))
 
-# we may pass the searchsorted* functions to the parent, and wrap the offset
-for f in [:searchsortedfirst, :searchsortedlast, :searchsorted]
-    _safe_f = Symbol("_safe_" * String(f))
-    @eval function $_safe_f(v::OffsetArray, x, ilo, ihi, o::Base.Ordering)
-        offset = firstindex(v) - firstindex(parent(v))
-        $f(parent(v), x, ilo - offset, ihi - offset, o) .+ offset
-    end
-    @eval Base.$f(v::OffsetVector, x, ilo::T, ihi::T, o::Base.Ordering) where T<:Integer =
-        $_safe_f(v, x, ilo, ihi, o)
-end
-
 ##
 # Deprecations
 ##