Merge branch 'maint'

* maint:
  Don't allow null in filenames

13 files changed, 323 insertions, 18 deletions

diff --git a/erts/emulator/beam/erl_bif_port.c b/erts/emulator/beam/erl_bif_port.c
index 4b73be55c6..3b8e70d44a 100644
--- a/erts/emulator/beam/erl_bif_port.c
+++ b/erts/emulator/beam/erl_bif_port.c
@@ -1076,7 +1076,7 @@ static byte* convert_environment(Process* p, Eterm env)
 	goto done;
     }
 
-    if ((size = erts_native_filename_need(all,encoding)) < 0) {
+    if ((size = erts_native_filename_need(all, encoding, 1)) < 0) {
 	goto done;
     }
 
diff --git a/erts/emulator/beam/erl_unicode.c b/erts/emulator/beam/erl_unicode.c
index 2d1d1443a7..efd2ca3db2 100644
--- a/erts/emulator/beam/erl_unicode.c
+++ b/erts/emulator/beam/erl_unicode.c
@@ -1988,7 +1988,7 @@ char *erts_convert_filename_to_encoding(Eterm name, char *statbuf, size_t statbu
 	is_list(name) || 
 	(allow_empty && is_nil(name))) {
 	Sint need;
-	if ((need = erts_native_filename_need(name,encoding)) < 0) {
+	if ((need = erts_native_filename_need(name, encoding, 0)) < 0) {
 	    return NULL;
 	}
 	if (encoding == ERL_FILENAME_WIN_WCHAR) {
@@ -2152,12 +2152,13 @@ Eterm erts_convert_native_to_filename(Process *p, byte *bytes)
 }
 
 
-Sint erts_native_filename_need(Eterm ioterm, int encoding) 
+Sint erts_native_filename_need(Eterm ioterm, int encoding, int allow_null) 
 {
     Eterm *objp;
     Eterm obj;
     DECLARE_ESTACK(stack);
     Sint need = 0;
+    int seen_null = 0;
 
     if (is_atom(ioterm)) {
 	Atom* ap;
@@ -2194,6 +2195,24 @@ Sint erts_native_filename_need(Eterm ioterm, int encoding)
 	default:
 	    need = -1;
 	}
+        if (!allow_null) {
+            /*
+             * Do not allow null in
+             * the middle of filenames
+             */
+            if (need > 0) {
+                byte *name = ap->name;
+                int len = ap->len;
+                for (i = 0; i < len; i++) {
+                    if (name[i] == 0)
+                        seen_null = 1;
+                    else if (seen_null) {
+                        need = -1;
+                        break;
+                    }
+                }
+            }
+        }
 	DESTROY_ESTACK(stack);
 	return need;
     }
@@ -2224,6 +2243,18 @@ L_Again:   /* Restart with sublist, old listend was pushed on stack */
 		if (is_small(obj)) { /* Always small */
 		    for(;;) {
 			Uint x = unsigned_val(obj);
+                        if (!allow_null) {
+                            /*
+                             * Do not allow null in
+                             * the middle of filenames
+                             */
+                            if (x == 0)
+                                seen_null = 1;
+                            else if (seen_null) {
+                                DESTROY_ESTACK(stack);
+                                return ((Sint) -1);
+                            }
+                        }
 			switch (encoding) {
 			case ERL_FILENAME_LATIN1:
 			    if (x > 255) {
@@ -2515,6 +2546,7 @@ BIF_RETTYPE prim_file_internal_name2native_1(BIF_ALIST_1)
 	BIF_ERROR(BIF_P,BADARG);
     }
     if (is_binary(BIF_ARG_1)) {
+        int seen_null = 0;
 	byte *temp_alloc = NULL;
 	byte *bytes;
 	byte *err_pos;
@@ -2524,10 +2556,18 @@ BIF_RETTYPE prim_file_internal_name2native_1(BIF_ALIST_1)
 	size = binary_size(BIF_ARG_1);
 	bytes = erts_get_aligned_binary_bytes(BIF_ARG_1, &temp_alloc);
 	if (encoding != ERL_FILENAME_WIN_WCHAR) {
+            Uint i;
 	    /*Add 0 termination only*/
 	    bin_term = new_binary(BIF_P, NULL, size+1);
 	    bin_p = binary_bytes(bin_term);
-	    memcpy(bin_p,bytes,size);
+            for (i = 0; i < size; i++) {
+                /* Don't allow null in the middle of filenames... */
+                if (bytes[i] == 0)
+                    seen_null = 1;
+                else if (seen_null)
+                    goto bin_name_error;
+                bin_p[i] = bytes[i];
+            }
 	    bin_p[size]=0;
 	    erts_free_aligned_binary_bytes(temp_alloc);
 	    BIF_RET(bin_term);
@@ -2541,6 +2581,11 @@ BIF_RETTYPE prim_file_internal_name2native_1(BIF_ALIST_1)
 	    bin_term = new_binary(BIF_P, 0, (size+1)*2);
 	    bin_p = binary_bytes(bin_term);
 	    while (size--) {
+                /* Don't allow null in the middle of filenames... */
+                if (*bytes == 0)
+                    seen_null = 1;
+                else if (seen_null)
+                    goto bin_name_error;
 		*bin_p++ = *bytes++;
 		*bin_p++ = 0;
 	    }
@@ -2558,11 +2603,14 @@ BIF_RETTYPE prim_file_internal_name2native_1(BIF_ALIST_1)
 	bin_p[num_chars*2+1] = 0;
 	erts_free_aligned_binary_bytes(temp_alloc);
 	BIF_RET(bin_term);
+    bin_name_error:
+        erts_free_aligned_binary_bytes(temp_alloc);
+        BIF_ERROR(BIF_P,BADARG);
     } /* binary */   
 	    
 
-    if ((need = erts_native_filename_need(BIF_ARG_1,encoding)) < 0) {
-	BIF_ERROR(BIF_P,BADARG);
+    if ((need = erts_native_filename_need(BIF_ARG_1, encoding, 0)) < 0) {
+        BIF_ERROR(BIF_P,BADARG);
     }
     if (encoding == ERL_FILENAME_WIN_WCHAR) {
 	need += 2;
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 09aeba00fa..604172857a 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -1238,7 +1238,7 @@ void erts_init_unicode(void);
 Sint erts_unicode_set_loop_limit(Sint limit);
 
 void erts_native_filename_put(Eterm ioterm, int encoding, byte *p) ;
-Sint erts_native_filename_need(Eterm ioterm, int encoding);
+Sint erts_native_filename_need(Eterm ioterm, int encoding, int allow_null);
 void erts_copy_utf8_to_utf16_little(byte *target, byte *bytes, int num_chars);
 int erts_analyze_utf8(byte *source, Uint size, 
 			byte **err_pos, Uint *num_chars, int *left);
diff --git a/erts/preloaded/src/erts.app.src b/erts/preloaded/src/erts.app.src
index 7ab06164b4..beb29a7c89 100644
--- a/erts/preloaded/src/erts.app.src
+++ b/erts/preloaded/src/erts.app.src
@@ -37,7 +37,7 @@
 	{registered, []},
 	{applications, []},
 	{env, []},
-	{runtime_dependencies, ["stdlib-3.0", "kernel-5.0", "sasl-3.0.1"]}
+	{runtime_dependencies, ["stdlib-3.4.3", "kernel-5.4.1", "sasl-3.0.1"]}
     ]}.
 
 %% vim: ft=erlang
diff --git a/lib/kernel/doc/src/file.xml b/lib/kernel/doc/src/file.xml
index b674b3ca93..593bee74fe 100644
--- a/lib/kernel/doc/src/file.xml
+++ b/lib/kernel/doc/src/file.xml
@@ -59,7 +59,7 @@
     terminal supports UTF-8, otherwise <c>latin1</c>. The default can
     be overridden using <c>+fnl</c> (to force <c>latin1</c> mode)
     or <c>+fnu</c> (to force <c>utf8</c> mode) when starting
-    <seealso marker="erts:erl"><c>erts:erl</c></seealso>.</p>
+    <seealso marker="erts:erl"><c>erl</c></seealso>.</p>
 
     <p>On operating systems with transparent naming, files can be
     inconsistently named, for example, some files are encoded in UTF-8 while
@@ -81,6 +81,22 @@
 
     <p>See also section <seealso marker="stdlib:unicode_usage#notes-about-raw-filenames">Notes About Raw Filenames</seealso> in the STDLIB User's Guide.</p>
 
+    <note><p>
+      File operations used to accept filenames containing
+      null characters (integer value zero). This caused
+      the name to be truncated at the first null character.
+      Filenames containing null characters inside the filename
+      are now <em>rejected</em> and will cause primitive
+      file operations fail.
+    </p></note>
+    <warning><p>
+      Currently null characters at the end of the filename
+      will be accepted by primitive file operations. Such
+      filenames are however still documented as invalid. The
+      implementation will also change in the future and
+      reject such filenames.
+    </p></warning>
+
   </description>
 
   <datatypes>
@@ -96,9 +112,21 @@
     </datatype>
     <datatype>
       <name name="filename"/>
+      <desc>
+        <p>
+	  See also the documentation of the
+	  <seealso marker="#type-name_all"><c>name_all()</c></seealso> type.
+	</p>
+      </desc>
     </datatype>
     <datatype>
       <name name="filename_all"/>
+      <desc>
+        <p>
+	  See also the documentation of the
+	  <seealso marker="#type-name_all"><c>name_all()</c></seealso> type.
+	</p>
+      </desc>
     </datatype>
     <datatype>
       <name name="io_device"/>
@@ -112,21 +140,23 @@
       <name name="name"/>
       <desc>
         <p>If VM is in Unicode filename mode, <c>string()</c> and <c>char()</c>
-          are allowed to be &gt; 255.
+          are allowed to be &gt; 255. See also the documentation of the
+	  <seealso marker="#type-name_all"><c>name_all()</c></seealso> type.
         </p>
       </desc>
     </datatype>
     <datatype>
       <name name="name_all"/>
       <desc>
-        <p>If VM is in Unicode filename mode, <c>string()</c> and <c>char()</c>
+        <p>If VM is in Unicode filename mode, characters
           are allowed to be &gt; 255.
           <c><anno>RawFilename</anno></c> is a filename not subject to
           Unicode translation,
           meaning that it can contain characters not conforming to
           the Unicode encoding expected from the file system
           (that is, non-UTF-8 characters although the VM is started
-          in Unicode filename mode).
+          in Unicode filename mode). Null characters (integer value zero)
+	  are <em>not</em> allowed in filenames (not even at the end).
         </p>
       </desc>
     </datatype>
diff --git a/lib/kernel/src/kernel.app.src b/lib/kernel/src/kernel.app.src
index 2a88cc7e26..b5e5f8eb73 100644
--- a/lib/kernel/src/kernel.app.src
+++ b/lib/kernel/src/kernel.app.src
@@ -120,6 +120,6 @@
   {applications, []},
   {env, [{error_logger, tty}]},
   {mod, {kernel, []}},
-  {runtime_dependencies, ["erts-9.1", "stdlib-3.4", "sasl-3.0"]}
+  {runtime_dependencies, ["erts-9.1.1", "stdlib-3.4.3", "sasl-3.0"]}
  ]
 }.
diff --git a/lib/kernel/test/file_name_SUITE.erl b/lib/kernel/test/file_name_SUITE.erl
index 899102c908..f23529fec9 100644
--- a/lib/kernel/test/file_name_SUITE.erl
+++ b/lib/kernel/test/file_name_SUITE.erl
@@ -302,7 +302,9 @@ check_normal(Mod) ->
 	      {ok, BC} = Mod:read(FD,1024),
 	      ok = file:close(FD)
 	  end || {regular,Name,Content} <- NormalDir ],
+	{error, badarg} = Mod:rename("fil1\0tmp_fil2","tmp_fil1"),
 	Mod:rename("fil1","tmp_fil1"),
+	{error, badarg} = Mod:read_file("tmp_fil1\0.txt"),
 	{ok, <<"fil1">>} = Mod:read_file("tmp_fil1"),
 	{error,enoent} = Mod:read_file("fil1"),
 	Mod:rename("tmp_fil1","fil1"),
diff --git a/lib/stdlib/doc/src/filelib.xml b/lib/stdlib/doc/src/filelib.xml
index 80c4acffdb..57c4348745 100644
--- a/lib/stdlib/doc/src/filelib.xml
+++ b/lib/stdlib/doc/src/filelib.xml
@@ -45,6 +45,30 @@
 
     <p>For more information about raw filenames, see the
       <seealso marker="kernel:file"><c>file</c></seealso> module.</p>
+
+    <note>
+      <p>
+	Functionality in this module generally assumes valid input and
+	does not necessarily fail on input that does not use a valid
+	encoding. You can validate the encoding of a filename using
+	<seealso marker="stdlib:filename#validate/1">filename:validate/1</seealso>.
+      </p>
+      <p>
+	File operations used to accept filenames containing
+	null characters (integer value zero). This caused
+	the name to be truncated at the first null character.
+	Filenames containing null characters inside the filename
+	are now <em>rejected</em> and will cause primitive
+	file operations fail.
+      </p>
+    </note>
+    <warning><p>
+      Currently null characters at the end of the filename
+      will be accepted by primitive file operations. Such
+      filenames are however still documented as invalid. The
+      implementation will also change in the future and
+      reject such filenames.
+    </p></warning>
   </description>
 
   <datatypes>
diff --git a/lib/stdlib/doc/src/filename.xml b/lib/stdlib/doc/src/filename.xml
index 14fd5ef787..b6028fc066 100644
--- a/lib/stdlib/doc/src/filename.xml
+++ b/lib/stdlib/doc/src/filename.xml
@@ -46,7 +46,10 @@
       filename by removing redundant directory separators, use
       <seealso marker="#join/1"><c>join/1</c></seealso>.</p>
 
-    <p>The module supports raw filenames in the way that if a binary is
+    <p>
+      The module supports
+      <seealso marker="unicode_usage#notes-about-raw-filenames">raw
+      filenames</seealso> in the way that if a binary is
       present, or the filename cannot be interpreted according to the return
       value of <seealso marker="kernel:file#native_name_encoding/0">
       <c>file:native_name_encoding/0</c></seealso>, a raw filename is also
@@ -56,6 +59,30 @@
       (the join operation is performed of course). For more information
       about raw filenames, see the
       <seealso marker="kernel:file"><c>file</c></seealso> module.</p>
+
+    <note>
+      <p>
+	Functionality in this module generally assumes valid input and
+	does not necessarily fail on input that does not use a valid
+	encoding. You can validate the encoding of a filename using
+	<seealso marker="#validate/1">filename:validate/1</seealso>.
+      </p>
+      <p>
+	File operations used to accept filenames containing
+	null characters (integer value zero). This caused
+	the name to be truncated at the first null character.
+	Filenames containing null characters inside the filename
+	are now <em>rejected</em> and will cause primitive
+	file operations fail.
+      </p>
+    </note>
+    <warning><p>
+      Currently null characters at the end of the filename
+      will be accepted by primitive file operations. Such
+      filenames are however still documented as invalid. The
+      implementation will also change in the future and
+      reject such filenames.
+    </p></warning>
   </description>
   <datatypes>
       <datatype>
@@ -555,6 +582,55 @@ unsafe</pre>
 ["a:/","msdev","include"]</pre>
       </desc>
     </func>
+
+    <func>
+      <name name="validate" arity="1"/>
+      <fsummary>Validate encoding of filename</fsummary>
+      <desc>
+	<p>
+	  Validates filename encoding. Returns <c>true</c> if
+	  <c><anno>FileName</anno></c> has a valid encoding;
+	  otherwise, returns <c>false</c>.
+	</p>
+	<taglist>
+	  <tag>Ordinary Filename</tag>
+	  <item>
+	    <p>
+	      Type: <c><anno>FileName</anno> = </c><seealso marker="kernel:file#type-name"><c>file:name()</c></seealso>
+	    </p>
+	    <p>
+	      Validates encoding against the
+	      <seealso marker="kernel:file#native_name_encoding/0">native file
+	      name encoding</seealso>, and the
+	      capabilities of the operating system used.
+	      Regardless of configuration and OS, null
+	      characters (integer value zero) will be
+	      rejected by the validation  (even when only
+	      present at the end of the filename).
+	    </p>
+	  </item>
+	  <tag><seealso marker="unicode_usage#notes-about-raw-filenames">Raw
+	  Filename</seealso></tag>
+	  <item>
+	    <p>
+	      Type: <c><anno>FileName</anno> = binary()</c>
+	    </p>
+	    <p>
+	      The encoding will not be interpreted, but
+	      null bytes (integer value zero) will be
+	      rejected by the validation (even when only
+	      present at the end of the filename).
+	    </p>
+	  </item>
+	</taglist>
+	<p>
+	  For information on filename encoding see the documentation
+	  of unicode filenames in
+	  <seealso marker="stdlib:unicode_usage#unicode_file_names">STDLIB
+	  Users Guide ➜ Using Unicode in Erlang ➜ Unicode Filenames</seealso>.
+	</p>
+      </desc>
+    </func>
   </funcs>
 </erlref>
 
diff --git a/lib/stdlib/doc/src/unicode_usage.xml b/lib/stdlib/doc/src/unicode_usage.xml
index 26dc46719e..ff1f864e22 100644
--- a/lib/stdlib/doc/src/unicode_usage.xml
+++ b/lib/stdlib/doc/src/unicode_usage.xml
@@ -719,8 +719,8 @@ Eshell V5.10.1  (abort with ^G)
   </section> 
 
   <section>
-    <title>Unicode Filenames</title>
     <marker id="unicode_file_names"/>
+    <title>Unicode Filenames</title>
     <p>Most modern operating systems support Unicode filenames in some way.
       There are many different ways to do this and Erlang by default treats the
       different approaches differently:</p>
@@ -855,8 +855,8 @@ Eshell V5.10.1  (abort with ^G)
     </note>
 
     <section>
-      <title>Notes About Raw Filenames</title>
       <marker id="notes-about-raw-filenames"/>
+      <title>Notes About Raw Filenames</title>
       <p>Raw filenames were introduced together with Unicode filename support
         in ERTS 5.8.2 (Erlang/OTP R14B01). The reason &quot;raw
         filenames&quot; were introduced in the system was
diff --git a/lib/stdlib/src/filename.erl b/lib/stdlib/src/filename.erl
index 63cfeae57b..73eccb226e 100644
--- a/lib/stdlib/src/filename.erl
+++ b/lib/stdlib/src/filename.erl
@@ -41,6 +41,7 @@
          safe_relative_path/1]).
 -export([find_src/1, find_src/2]). % deprecated
 -export([basedir/2, basedir/3]).
+-export([validate/1]).
 
 %% Undocumented and unsupported exports.
 -export([append/2]).
@@ -1135,3 +1136,72 @@ basedir_os_type() ->
         {win32,_}     -> windows;
         _             -> linux
     end.
+
+%%
+%% validate/1
+%%
+
+-spec validate(FileName) -> boolean() when
+      FileName :: file:name_all().
+
+validate(FileName) when is_binary(FileName) ->
+    %% Raw filename...
+    validate_bin(FileName);
+validate(FileName) when is_list(FileName);
+                        is_atom(FileName) ->
+    validate_list(FileName,
+                  file:native_name_encoding(),
+                  os:type()).
+
+validate_list(FileName, Enc, Os) ->
+    try
+        true = validate_list(FileName, Enc, Os, 0) > 0
+    catch
+        _ : _ -> false
+    end.
+
+validate_list([], _Enc, _Os, Chars) ->
+    Chars;
+validate_list(C, Enc, Os, Chars) when is_integer(C) ->
+    validate_char(C, Enc, Os),
+    Chars+1;
+validate_list(A, Enc, Os, Chars) when is_atom(A) ->
+    validate_list(atom_to_list(A), Enc, Os, Chars);
+validate_list([H|T], Enc, Os, Chars) ->
+    NewChars = validate_list(H, Enc, Os, Chars),
+    validate_list(T, Enc, Os, NewChars).
+
+%% C is always an integer...
+% validate_char(C, _, _) when not is_integer(C) ->
+%     throw(invalid);
+validate_char(C, _, _) when C < 1 ->
+    throw(invalid); %% No negative or null characters...
+validate_char(C, latin1, _) when C > 255 ->
+    throw(invalid);
+validate_char(C, utf8, _) when C >= 16#110000 ->
+    throw(invalid);
+validate_char(C, utf8, {win32, _}) when C > 16#ffff ->
+    throw(invalid); %% invalid win wchar...
+validate_char(_C, utf8, {win32, _}) ->
+    ok; %% Range below is accepted on windows...
+validate_char(C, utf8, _) when 16#D800 =< C, C =< 16#DFFF ->
+    throw(invalid); %% invalid unicode range...
+validate_char(_, _, _) ->
+    ok.
+
+validate_bin(Bin) ->
+    %% Raw filename. That is, we do not interpret
+    %% the encoding, but we still do not accept
+    %% null characters...
+    try
+        true = validate_bin(Bin, 0) > 0
+    catch
+        _ : _ -> false
+    end.
+
+validate_bin(<<>>, Bs) ->
+    Bs;
+validate_bin(<<0, _Rest/binary>>, _Bs) ->
+    throw(invalid); %% No null characters allowed...
+validate_bin(<<_B, Rest/binary>>, Bs) ->
+    validate_bin(Rest, Bs+1).
diff --git a/lib/stdlib/src/stdlib.app.src b/lib/stdlib/src/stdlib.app.src
index 3c449d3cb9..41c89270aa 100644
--- a/lib/stdlib/src/stdlib.app.src
+++ b/lib/stdlib/src/stdlib.app.src
@@ -107,7 +107,7 @@
                dets]},
   {applications, [kernel]},
   {env, []},
-  {runtime_dependencies, ["sasl-3.0","kernel-5.0","erts-9.0","crypto-3.3",
+  {runtime_dependencies, ["sasl-3.0","kernel-5.4.1","erts-9.1.1","crypto-3.3",
 			  "compiler-5.0"]}
 ]}.
 
diff --git a/lib/stdlib/test/filename_SUITE.erl b/lib/stdlib/test/filename_SUITE.erl
index fc77593bb8..4c82ec1c22 100644
--- a/lib/stdlib/test/filename_SUITE.erl
+++ b/lib/stdlib/test/filename_SUITE.erl
@@ -30,6 +30,7 @@
 -export([pathtype_bin/1,rootname_bin/1,split_bin/1]).
 -export([t_basedir_api/1, t_basedir_xdg/1, t_basedir_windows/1]).
 -export([safe_relative_path/1]).
+-export([validate/1]).
 
 -include_lib("common_test/include/ct.hrl").
 
@@ -43,7 +44,8 @@ all() ->
      absname_bin, absname_bin_2,
      {group,p},
      t_basedir_xdg, t_basedir_windows,
-     safe_relative_path].
+     safe_relative_path,
+     validate].
 
 groups() -> 
     [{p, [parallel],
@@ -1011,3 +1013,56 @@ basedir_xdg_def(Type,Home,Name) ->
                         Dir <- ["/usr/local/share/","/usr/share/"]];
         site_config -> [filename:join(["/etc/xdg",Name])]
     end.
+
+validate(Config) when is_list(Config) ->
+    true = filename:validate(blipp),
+    false = filename:validate('bli\0pp'),
+    false = filename:validate('blipp\0'),
+    true = filename:validate("blipp"),
+    false = filename:validate("bli"++[0]++"pp"),
+    false = filename:validate("blipp"++[0]),
+    true = filename:validate(["one ", blipp, "blopp"]),
+    false = filename:validate(["one ", 'bli\0pp', "blopp"]),
+    false = filename:validate(["one ", 'blipp\0', "blopp"]),
+    false = filename:validate(["one ", 'blipp', "blopp\0"]),
+    false = filename:validate([0]),
+    false = filename:validate([]),
+    false = filename:validate([[[]],[[[[],[[[[[[[[]]], '', [[[[[]]]]]]]]]]]]]]),
+    false = filename:validate([16#110000]),
+    false = filename:validate([16#110001]),
+    false = filename:validate([16#110000*2]),
+    case file:native_name_encoding() of
+        latin1 ->
+            true = filename:validate(lists:seq(1, 255)),
+            false = filename:validate([256]);
+        utf8 ->
+            true = filename:validate(lists:seq(1, 16#D7FF)),
+            true = filename:validate(lists:seq(16#E000, 16#FFFF)),
+            true = filename:validate([16#FFFF]),
+            case os:type() of
+                {win32, _} ->
+                    false = filename:validate([16#10000]),
+                    true = filename:validate(lists:seq(16#D800,16#DFFF));
+                _ ->
+                    true = filename:validate([16#10000]),
+                    true = filename:validate([16#10FFFF]),
+                    lists:foreach(fun (C) ->
+                                          false = filename:validate([C])
+                                  end,
+                                  lists:seq(16#D800,16#DFFF))
+            end
+                        
+    end,
+    true = filename:validate(<<1,17,255>>),
+    false = filename:validate(<<1,0,17,255>>),
+    false = filename:validate(<<1,17,255,0>>),
+    false = filename:validate(<<>>),
+    lists:foreach(fun (N) ->
+                          true = filename:validate(N)
+                  end,
+                  code:get_path()),
+    ok.
+
+            
+    
+