From bafd88c211063131f27ce5c51a37d13bac5299f7 Mon Sep 17 00:00:00 2001
From: Kleis Auke Wolthuizen <github@kleisauke.nl>
Date: Mon, 4 Nov 2024 10:04:35 +0100
Subject: [PATCH] Ensure variadic call is null-terminated

---
 CHANGELOG.md      | 2 ++
 lib/vips/image.rb | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index caabbb5..9bb5fd7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## master
 
+* fix `Image#add_alpha()` with libvips 8.16 [kleisauke]
+
 ## Version 2.2.2 (2024-07-17)
 
 * fix compat with unified (semistatic) libvips binaries [kleisauke]
diff --git a/lib/vips/image.rb b/lib/vips/image.rb
index 45bd2ed..e777d47 100644
--- a/lib/vips/image.rb
+++ b/lib/vips/image.rb
@@ -973,7 +973,7 @@ def has_alpha?
       # @return [Image] new image
       def add_alpha
         ptr = GenericPtr.new
-        result = Vips.vips_addalpha self, ptr
+        result = Vips.vips_addalpha self, ptr, :pointer, nil
         raise Vips::Error if result != 0
 
         Vips::Image.new ptr[:value]