From ac41e2a0d446de8249733d902bb774695c9d61f7 Mon Sep 17 00:00:00 2001
From: Daniel Wennberg <daniel.wennberg@gmail.com>
Date: Fri, 1 Mar 2024 16:24:30 +0100
Subject: [PATCH] Fix `hypot` promotion bug (#53541)

Fixes #53505
---
 base/math.jl |  4 ++--
 test/math.jl | 10 ++++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/base/math.jl b/base/math.jl
index 71a4ef9f34882..c3c15505c5f8f 100644
--- a/base/math.jl
+++ b/base/math.jl
@@ -817,8 +817,8 @@ true
 ```
 """
 hypot(x::Number) = abs(float(x))
-hypot(x::Number, y::Number) = _hypot(promote(float(x), y)...)
-hypot(x::Number, y::Number, xs::Number...) = _hypot(promote(float(x), y, xs...))
+hypot(x::Number, y::Number) = _hypot(float.(promote(x, y))...)
+hypot(x::Number, y::Number, xs::Number...) = _hypot(float.(promote(x, y, xs...)))
 function _hypot(x, y)
     # preserves unit
     axu = abs(x)
diff --git a/test/math.jl b/test/math.jl
index f3c6dc5bb103f..f551bb3a5d4b7 100644
--- a/test/math.jl
+++ b/test/math.jl
@@ -1355,6 +1355,16 @@ end
     # hypot on Complex returns Real
     @test (@inferred hypot(3, 4im)) === 5.0
     @test (@inferred hypot(3, 4im, 12)) === 13.0
+    @testset "promotion, issue #53505" begin
+        @testset "Int,$T" for T in (Float16, Float32, Float64, BigFloat)
+            for args in ((3, 4), (3, 4, 12))
+                for i in eachindex(args)
+                    targs = ntuple(j -> (j == i) ? T(args[j]) : args[j], length(args))
+                    @test (@inferred hypot(targs...)) isa float(eltype(promote(targs...)))
+                end
+            end
+        end
+    end
 end
 
 struct BadFloatWrapper <: AbstractFloat