From dde8c9f8524806ad19b0b07ab1a084640ee6547d Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Mon, 21 Apr 2025 22:52:09 -0700
Subject: [PATCH 1/2] Make pointer size consistent between backends

---
 lib/fiddle/ffi_backend.rb   | 5 ++++-
 test/fiddle/test_pointer.rb | 8 ++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/fiddle/ffi_backend.rb b/lib/fiddle/ffi_backend.rb
index 0c385510..e0d63bb9 100644
--- a/lib/fiddle/ffi_backend.rb
+++ b/lib/fiddle/ffi_backend.rb
@@ -323,7 +323,7 @@ def initialize(addr, size = nil, free = nil)
               FFI::Pointer.new(Integer(addr))
             end
 
-      @size = size ? size : ptr.size
+      @size = size ? size : (ptr.size_limit? ? ptr.size : 0)
       @free = free
       @ffi_ptr = ptr
       @freed = false
@@ -413,6 +413,8 @@ def to_i
     def to_s(len = nil)
       if len
         ffi_ptr.read_string(len)
+      elsif @size == 0
+        ffi_ptr.read_string
       else
         ffi_ptr.get_string(0, @size)
       end
@@ -486,6 +488,7 @@ def -@
     def ref
       cptr = Pointer.malloc(FFI::Type::POINTER.size, RUBY_FREE)
       cptr.ffi_ptr.put_pointer(0, ffi_ptr)
+      cptr.size = 0
       cptr
     end
   end
diff --git a/test/fiddle/test_pointer.rb b/test/fiddle/test_pointer.rb
index ebb5451f..6f086f00 100644
--- a/test/fiddle/test_pointer.rb
+++ b/test/fiddle/test_pointer.rb
@@ -81,6 +81,9 @@ def test_to_str
 
       ptr[5] = 0
       assert_equal "hello\0world", ptr.to_str
+
+      ptr.size = 0
+      assert_equal "", ptr.to_str
     end
 
     def test_to_s
@@ -93,6 +96,9 @@ def test_to_s
       ptr[5] = 0
       assert_equal 'hello', ptr.to_s
       assert_equal "hello\0", ptr.to_s(6)
+
+      ptr.size = 0
+      assert_equal "hello", ptr.to_s
     end
 
     def test_minus
@@ -256,6 +262,8 @@ def test_size
       Pointer.malloc(4, Fiddle::RUBY_FREE) do |ptr|
         assert_equal 4, ptr.size
       end
+      assert_equal 0, Pointer.new(0).size
+      assert_equal 0, Pointer.new(0).ref.size
     end
 
     def test_size=

From 66203d45c9b2dc0535f4aa91f2ba9472cab7b48e Mon Sep 17 00:00:00 2001
From: Andrew Kane <acekane1@gmail.com>
Date: Mon, 21 Apr 2025 23:19:16 -0700
Subject: [PATCH 2/2] Update lib/fiddle/ffi_backend.rb

Co-authored-by: Sutou Kouhei <kou@cozmixng.org>
---
 lib/fiddle/ffi_backend.rb | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/fiddle/ffi_backend.rb b/lib/fiddle/ffi_backend.rb
index e0d63bb9..fc1746fd 100644
--- a/lib/fiddle/ffi_backend.rb
+++ b/lib/fiddle/ffi_backend.rb
@@ -323,7 +323,13 @@ def initialize(addr, size = nil, free = nil)
               FFI::Pointer.new(Integer(addr))
             end
 
-      @size = size ? size : (ptr.size_limit? ? ptr.size : 0)
+      if size
+        @size = size
+      elsif ptr.size_limit?
+        @size = ptr.size
+      else
+        @size = 0
+      end
       @free = free
       @ffi_ptr = ptr
       @freed = false