From 9eb9a8e046294ce1a64f40dce2ba8b75dae284ac Mon Sep 17 00:00:00 2001
From: Jishnu Bhattacharya <jishnub@users.noreply.github.com>
Date: Thu, 30 Jun 2022 10:05:50 +0530
Subject: [PATCH] avoid overflow in mean

---
 .gitignore        | 1 +
 src/Statistics.jl | 5 +++--
 test/runtests.jl  | 9 +++++++++
 3 files changed, 13 insertions(+), 2 deletions(-)
 create mode 100644 .gitignore

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..ba39cc53
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+Manifest.toml
diff --git a/src/Statistics.jl b/src/Statistics.jl
index 040ac972..989589c5 100644
--- a/src/Statistics.jl
+++ b/src/Statistics.jl
@@ -183,8 +183,9 @@ function _mean(f, A::AbstractArray, dims::Dims=:) where Dims
 end
 
 function mean(r::AbstractRange{<:Real})
-    isempty(r) && return oftype((first(r) + last(r)) / 2, NaN)
-    (first(r) + last(r)) / 2
+    centralval = first(r) + (last(r) - first(r)) / 2
+    isempty(r) && return oftype(centralval, NaN)
+    centralval
 end
 
 median(r::AbstractRange{<:Real}) = mean(r)
diff --git a/test/runtests.jl b/test/runtests.jl
index 35242c27..32a39dd7 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -182,6 +182,15 @@ end
     end
     @test mean(2:1) === NaN
     @test mean(big(2):1) isa BigFloat
+
+    @testset "issue #120" begin
+        @test mean(Int8(123):Int8(123)) == 123
+        @test median(Int8(123):Int8(123)) == 123
+        @test mean(Int8(126):Int8(127)) == 126.5
+        @test mean(typemax(Int):typemax(Int)) == float(typemax(Int))
+        @test mean(UInt8(255):UInt8(255)) == 255
+        @test mean(Float16(12345):Float16(54321)) ≈ Float16(mean(Float32(12345):Float32(54321)))
+    end
 end
 
 @testset "var & std" begin