From 067e6acaf1e9165de717419ab166d88bc9488871 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lars=20G=C3=B6ttgens?= <lars.goettgens@rwth-aachen.de>
Date: Mon, 17 Jul 2023 23:00:32 +0200
Subject: [PATCH] Extensions do not commit piracy against base package

---
 src/Aqua.jl   | 2 ++
 src/piracy.jl | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/src/Aqua.jl b/src/Aqua.jl
index 2f203016..fcc359ba 100644
--- a/src/Aqua.jl
+++ b/src/Aqua.jl
@@ -4,6 +4,8 @@ using Base: PkgId, UUID
 using Pkg: Pkg, TOML
 using Test
 
+const JULIA_HAS_EXTENSIONS = isdefined(Base, :get_extension) # introduced in v1.9
+
 try
     findnext('a', "a", 1)
 catch
diff --git a/src/piracy.jl b/src/piracy.jl
index e29018bf..34e53dd2 100644
--- a/src/piracy.jl
+++ b/src/piracy.jl
@@ -1,5 +1,7 @@
 module Piracy
 
+using Aqua: JULIA_HAS_EXTENSIONS
+
 if VERSION >= v"1.6-"
     using Test: is_in_mods
 else
@@ -160,6 +162,11 @@ end
 function is_pirate(meth::Method; treat_as_own = Union{Function,Type}[])
     method_pkg = Base.PkgId(meth.module)
 
+    # Package extensions behave as the package itself
+    @static if JULIA_HAS_EXTENSIONS
+        method_pkg = get(Base.EXT_PRIMED, method_pkg, method_pkg)
+    end
+
     signature = Base.unwrap_unionall(meth.sig)
 
     # the first parameter in the signature is the function type, and it