Index: tests/natools-s_expressions-atom_buffers-tests.adb
==================================================================
--- tests/natools-s_expressions-atom_buffers-tests.adb
+++ tests/natools-s_expressions-atom_buffers-tests.adb
@@ -30,10 +30,11 @@
       Test_Query (Report);
       Test_Query_Null (Report);
       Test_Reset (Report);
       Test_Reverse_Append (Report);
       Test_Invert (Report);
+      Test_Empty_Append (Report);
    end All_Tests;
 
 
 
    ----------------------
@@ -447,6 +448,20 @@
       end;
    exception
       when Error : others => Report.Report_Exception (Name, Error);
    end Test_Reverse_Append;
 
+
+   procedure Test_Empty_Append (Report : in out NT.Reporter'Class) is
+      Test : NT.Test := Report.Item ("Empty append on empty buffer");
+   begin
+      declare
+         Buffer : Atom_Buffer;
+      begin
+         Buffer.Append (Null_Atom);
+         Test_Tools.Test_Atom (Test, Null_Atom, Buffer.Data);
+      end;
+   exception
+      when Error : others => Test.Report_Exception (Error);
+   end Test_Empty_Append;
+
 end Natools.S_Expressions.Atom_Buffers.Tests;

Index: tests/natools-s_expressions-atom_buffers-tests.ads
==================================================================
--- tests/natools-s_expressions-atom_buffers-tests.ads
+++ tests/natools-s_expressions-atom_buffers-tests.ads
@@ -27,14 +27,15 @@
    package NT renames Natools.Tests;
 
    procedure All_Tests (Report : in out NT.Reporter'Class);
 
    procedure Test_Block_Append (Report : in out NT.Reporter'Class);
+   procedure Test_Empty_Append (Report : in out NT.Reporter'Class);
    procedure Test_Octet_Append (Report : in out NT.Reporter'Class);
    procedure Test_Invert (Report : in out NT.Reporter'Class);
    procedure Test_Preallocate (Report : in out NT.Reporter'Class);
    procedure Test_Query (Report : in out NT.Reporter'Class);
    procedure Test_Query_Null (Report : in out NT.Reporter'Class);
    procedure Test_Reset (Report : in out NT.Reporter'Class);
    procedure Test_Reverse_Append (Report : in out NT.Reporter'Class);
 
 end Natools.S_Expressions.Atom_Buffers.Tests;