From b9f32379b0be96e3117566862991d516d8d5cb42 Mon Sep 17 00:00:00 2001
From: Chunji Wang <chunji.wang@samsung.com>
Date: Thu, 31 Aug 2023 19:00:05 -0700
Subject: [PATCH 1/2] Prevent overflow in `mean(::AbstractRange)` and relax
 type constraint

---
 src/Statistics.jl |  6 +++---
 test/runtests.jl  | 12 ++++++++++--
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/Statistics.jl b/src/Statistics.jl
index 64ba7560..74f325df 100644
--- a/src/Statistics.jl
+++ b/src/Statistics.jl
@@ -197,9 +197,9 @@ if !isdefined(Base, :mean)
         end
     end
 
-    function mean(r::AbstractRange{<:Real})
-        isempty(r) && return oftype((first(r) + last(r)) / 2, NaN)
-        (first(r) + last(r)) / 2
+    function mean(r::AbstractRange{T}) where T
+        isempty(r) && return zero(T) / 0
+        return first(r) / 2 + last(r) / 2
     end
 end
 
diff --git a/test/runtests.jl b/test/runtests.jl
index 6903f90b..8d8fbec4 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -194,8 +194,16 @@ end
             @test f(2:0.1:n) ≈ f([2:0.1:n;])
         end
     end
-    @test mean(2:1) === NaN
-    @test mean(big(2):1) isa BigFloat
+    @test mean(2:0.1:4) === 3.0  # N.B. mean([2:0.1:4;]) != 3
+    @test mean(LinRange(2im, 4im, 21)) === 3.0im
+    @test mean(2:1//10:4) === 3//1
+    @test isnan(@inferred(mean(2:1))::Float64)
+    @test isnan(@inferred(mean(big(2):1))::BigFloat)
+    z = @inferred(mean(LinRange(2im, 1im, 0)))::ComplexF64
+    @test isnan(real(z)) & isnan(imag(z))
+    @test_throws DivideError mean(2//1:1)
+    @test mean(typemax(Int):typemax(Int)) === float(typemax(Int))
+    @test mean(prevfloat(Inf):prevfloat(Inf)) === prevfloat(Inf)
 end
 
 @testset "var & std" begin

From 9a31749b051c068590c1ad133a8b105861319ab8 Mon Sep 17 00:00:00 2001
From: Chunji Wang <7267426+chunjiw@users.noreply.github.com>
Date: Sat, 9 Sep 2023 12:28:46 -0700
Subject: [PATCH 2/2] Make `mean(::AbstractRange)` fix more readable

Co-authored-by: Milan Bouchet-Valat <nalimilan@club.fr>
---
 src/Statistics.jl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Statistics.jl b/src/Statistics.jl
index 74f325df..6961feeb 100644
--- a/src/Statistics.jl
+++ b/src/Statistics.jl
@@ -198,8 +198,8 @@ if !isdefined(Base, :mean)
     end
 
     function mean(r::AbstractRange{T}) where T
-        isempty(r) && return zero(T) / 0
-        return first(r) / 2 + last(r) / 2
+        isempty(r) && return zero(T)/0
+        return first(r)/2 + last(r)/2
     end
 end