diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 01e2a7625..3bf9f45d5 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,9 @@
+2009-10-09  Corinna Vinschen  <corinna@vinschen.de>
+
+	* path.cc (tfx_chars): Convert all ASCII control characters except
+	ASCII NUL as well.  Change layout to make the conversions more clear.
+	Add comment.
+
 2009-10-09  Corinna Vinschen  <corinna@vinschen.de>
 
 	* include/cygwin/config.h (DEFAULT_LOCALE): Define as "C.UTF-8".
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 7e89cb050..2020eda8f 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -395,23 +395,45 @@ path_conv::set_normalized_path (const char *path_copy)
     }
 }
 
+/* Transform characters invalid for Windows filenames to the Unicode private
+   use area in the U+f0XX range.  The affected characters are all control
+   chars 1 <= c <= 31, as well as the characters " * : < > ? |.  The backslash
+   is affected as well, but we can't transform it as long as we accept Win32
+   paths as input.
+   The reverse functionality is in strfuncs.cc, function sys_cp_wcstombs. */
 WCHAR tfx_chars[] NO_COPY = {
-   0,   1,   2,   3,   4,   5,   6,   7,
-   8,   9,  10,  11,  12,  13,  14,  15,
-  16,  17,  18,  19,  20,  21,  22,  23,
-  24,  25,  26,  27,  28,  29,  30,  31,
-  32, '!', 0xf000 | '"', '#', '$', '%', '&',  39,
-  '(', ')', 0xf000 | '*', '+', ',', '-', '.', '\\',
- '0', '1', '2', '3', '4', '5', '6', '7',
- '8', '9', 0xf000 | ':', ';', 0xf000 | '<', '=', 0xf000 | '>', 0xf000 | '?',
- '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
- 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
- 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
- 'X', 'Y', 'Z', '[',  '\\', ']', '^', '_',
- '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g',
- 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
- 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
- 'x', 'y', 'z', '{', 0xf000 | '|', '}', '~', 127
+            0, 0xf000 |   1, 0xf000 |   2, 0xf000 |   3,
+ 0xf000 |   4, 0xf000 |   5, 0xf000 |   6, 0xf000 |   7,
+ 0xf000 |   8, 0xf000 |   9, 0xf000 |  10, 0xf000 |  11,
+ 0xf000 |  12, 0xf000 |  13, 0xf000 |  14, 0xf000 |  15,
+ 0xf000 |  16, 0xf000 |  17, 0xf000 |  18, 0xf000 |  19,
+ 0xf000 |  20, 0xf000 |  21, 0xf000 |  22, 0xf000 |  23,
+ 0xf000 |  24, 0xf000 |  25, 0xf000 |  26, 0xf000 |  27,
+ 0xf000 |  28, 0xf000 |  29, 0xf000 |  30, 0xf000 |  31,
+          ' ',          '!', 0xf000 | '"',          '#',
+          '$',          '%',          '&',           39,
+          '(',          ')', 0xf000 | '*',          '+',
+          ',',          '-',          '.',          '\\',
+          '0',          '1',          '2',          '3',
+          '4',          '5',          '6',          '7',
+          '8',          '9', 0xf000 | ':',          ';',
+ 0xf000 | '<',          '=', 0xf000 | '>', 0xf000 | '?',
+          '@',          'A',          'B',          'C',
+          'D',          'E',          'F',          'G',
+          'H',          'I',          'J',          'K',
+          'L',          'M',          'N',          'O',
+          'P',          'Q',          'R',          'S',
+          'T',          'U',          'V',          'W',
+          'X',          'Y',          'Z',          '[',
+          '\\',          ']',          '^',          '_',
+          '`',          'a',          'b',          'c',
+          'd',          'e',          'f',          'g',
+          'h',          'i',          'j',          'k',
+          'l',          'm',          'n',          'o',
+          'p',          'q',          'r',          's',
+          't',          'u',          'v',          'w',
+          'x',          'y',          'z',          '{',
+ 0xf000 | '|',          '}',          '~',          127
 };
 
 void