From 934ad153352cc584d83348436ccdc00f86e18cbf Mon Sep 17 00:00:00 2001
From: Charlie Savage <cfis@savagexi.com>
Date: Thu, 28 Mar 2024 01:16:10 -0700
Subject: [PATCH] If you call FFI::Pointer#== with an instance of an object
 that is not FFI::Pointer or descendants an exception is thrown - "INTERNAL
 ERROR!!! TypeError: wrong argument type Module (expected FFI::Pointer). In my
 case, this then causes the RubyMine debugger (debase) to blow up, making
 debugging harder.

This PR updates FFI::Pointer#== to return false if a pointer is compared to a non-pointer object, which is the expected behavior.
---
 ext/ffi_c/Pointer.c      |  7 ++++++-
 spec/ffi/pointer_spec.rb | 13 +++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/ext/ffi_c/Pointer.c b/ext/ffi_c/Pointer.c
index 31b9f8036..affa35901 100644
--- a/ext/ffi_c/Pointer.c
+++ b/ext/ffi_c/Pointer.c
@@ -314,7 +314,12 @@ ptr_equals(VALUE self, VALUE other)
         return ptr->memory.address == NULL ? Qtrue : Qfalse;
     }
 
-    return ptr->memory.address == POINTER(other)->address ? Qtrue : Qfalse;
+    if (!rb_obj_is_kind_of(other, rbffi_PointerClass)) {
+        return Qfalse;
+    }
+    else {
+        return ptr->memory.address == POINTER(other)->address ? Qtrue : Qfalse;
+    }
 }
 
 /*
diff --git a/spec/ffi/pointer_spec.rb b/spec/ffi/pointer_spec.rb
index a7114966b..bda270189 100644
--- a/spec/ffi/pointer_spec.rb
+++ b/spec/ffi/pointer_spec.rb
@@ -76,6 +76,16 @@ def to_ptr
     expect(FFI::Pointer::NULL.to_ptr).to eq(FFI::Pointer::NULL)
   end
 
+  it "equals itself" do
+    memory = FFI::MemoryPointer.new :pointer
+    expect(memory == memory).to be true
+  end
+
+  it "does not equal non pointers" do
+    memory = FFI::MemoryPointer.new :pointer
+    expect(memory == Hash.new).to be false
+  end
+
   describe "pointer type methods" do
 
     it "#read_pointer" do
@@ -150,6 +160,9 @@ def to_ptr
     it 'returns true when compared with nil' do
       expect((FFI::Pointer::NULL == nil)).to be true
     end
+    it 'returns false when compared with a non-pointer object' do
+      expect((FFI::Pointer::NULL == Array.new)).to be false
+    end
     it 'should not raise an error when attempting read/write zero length array' do
       null_ptr = FFI::Pointer::NULL
       expect( null_ptr.read_array_of_uint(0) ).to eq([])