Merge pull request #692 from eregon/fix_read_string_zero_encoding

Fix FFI::Pointer#read_string(0) to return a binary String
ffi · Apr 12, 2019 · 59934bb · 59934bb
2 parents 6d05806 + 4c92387
commit 59934bb
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diff --git a/lib/ffi/pointer.rb b/lib/ffi/pointer.rb
@@ -49,7 +49,7 @@ def self.size
     # equivalent string if +len+ is not +nil+.
     def read_string(len=nil)
       if len
-        return '' if len == 0
+        return ''.b if len == 0
         get_bytes(0, len)
       else
         get_string(0)

diff --git a/spec/ffi/rbx/memory_pointer_spec.rb b/spec/ffi/rbx/memory_pointer_spec.rb
@@ -37,6 +37,7 @@ module CTest
 
   it "reads back an empty string" do
     expect(FFI::Pointer::NULL.read_string(0)).to eq('')
+    expect(FFI::Pointer::NULL.read_string(0).encoding).to eq(Encoding::BINARY)
   end
 
   it "makes a pointer for a certain number of bytes" do