From abb53d2eba8b967c2186efa5556ecbfec29b413e Mon Sep 17 00:00:00 2001
From: Oscar Dowson <o.dowson@gmail.com>
Date: Thu, 2 Apr 2026 10:01:45 +1300
Subject: [PATCH] Fix /(::Zero, ::AbstractMutable)

---
 src/dispatch.jl     | 7 +++++++
 src/rewrite.jl      | 3 +--
 test/test_basics.jl | 6 ++++++
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/dispatch.jl b/src/dispatch.jl
index d74aa55..807eb9e 100644
--- a/src/dispatch.jl
+++ b/src/dispatch.jl
@@ -23,6 +23,13 @@ Base.:+(x::AbstractMutable, ::Zero) = copy_if_mutable(x)
 Base.:-(::Zero, x::AbstractMutable) = operate(-, x)
 Base.:-(x::AbstractMutable, ::Zero) = copy_if_mutable(x)
 
+function Base.:/(z::Zero, x::AbstractMutable)
+    if iszero(x)
+        throw(DivideError())
+    end
+    return z
+end
+
 function Base.sum(
     a::AbstractArray{T};
     dims = :,
diff --git a/src/rewrite.jl b/src/rewrite.jl
index f37ca58..bfc9682 100644
--- a/src/rewrite.jl
+++ b/src/rewrite.jl
@@ -85,9 +85,8 @@ Base.:*(z::Zero) = z
 function Base.:/(z::Zero, x::Number)
     if iszero(x)
         throw(DivideError())
-    else
-        return z
     end
+    return z
 end
 
 Base.iszero(::Zero) = true
diff --git a/test/test_basics.jl b/test/test_basics.jl
index ec18bd6..7bbf154 100644
--- a/test/test_basics.jl
+++ b/test/test_basics.jl
@@ -546,6 +546,12 @@ function test_operate()
     return
 end
 
+function test_op_divide()
+    @test MA.Zero() / DummyBigInt(1) == MA.Zero()
+    @test_throws DivideError MA.Zero() / DummyBigInt(0)
+    return
+end
+
 end  # TestBasics
 
 TestBasics.runtests()