Index: unicodeobject.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/unicodeobject.c,v
retrieving revision 2.202
diff -u -r2.202 unicodeobject.c
--- unicodeobject.c	26 Nov 2003 08:21:35 -0000	2.202
+++ unicodeobject.c	29 Nov 2003 01:29:14 -0000
@@ -2591,24 +2591,52 @@
 {
     PyUnicodeObject *v;
     Py_UNICODE *p;
+    DWORD usize;
+    DWORD dwFlags;
+
+    /* check and handle 'errors' arg */
+    if (errors==NULL || strcmp(errors, "strict")==0)
+        dwFlags = MB_ERR_INVALID_CHARS;
+    else if (strcmp(errors, "ignore")==0 || strcmp(errors, "replace")==0)
+        dwFlags = 0;
+    else
+        return PyErr_Format(PyExc_ValueError,
+                            "mbcs encoding does not support errors='%s'", 
+                            errors);
+
+    /* get the size of the result */
+    usize = MultiByteToWideChar(CP_ACP, dwFlags, s, size, NULL, 0);
 
-    /* First get the size of the result */
-    DWORD usize = MultiByteToWideChar(CP_ACP, 0, s, size, NULL, 0);
     if (size > 0 && usize==0)
-        return PyErr_SetFromWindowsErrWithFilename(0, NULL);
+        goto mbcs_decode_error;
 
     v = _PyUnicode_New(usize);
     if (v == NULL)
         return NULL;
     if (usize == 0)
-	return (PyObject *)v;
+        return (PyObject *)v;
     p = PyUnicode_AS_UNICODE(v);
-    if (0 == MultiByteToWideChar(CP_ACP, 0, s, size, p, usize)) {
+    if (0 == MultiByteToWideChar(CP_ACP, dwFlags, s, size, p, usize)) {
         Py_DECREF(v);
-        return PyErr_SetFromWindowsErrWithFilename(0, NULL);
+        goto mbcs_decode_error;
     }
 
     return (PyObject *)v;
+mbcs_decode_error:
+    /* If the last error was ERROR_NO_UNICODE_TRANSLATION, then
+       we raise a UnicodeDecodeError - else it is a 'generic'
+       windows error
+     */
+    if (GetLastError()==ERROR_NO_UNICODE_TRANSLATION) {
+        /* Ideally, we should get reason from FormatMessage - this
+           is the Windows 2000 English version of the message
+        */
+        const char *reason = "No mapping for the Unicode character exists "
+                             "in the target multi-byte code page.";
+        /* what should we use for startinpos and endinpos? */
+        return PyUnicodeDecodeError_Create("mbcs", s, size, 0, 0, reason);
+    }
+    return PyErr_SetFromWindowsErrWithFilename(0, NULL);
 }
 
 PyObject *PyUnicode_EncodeMBCS(const Py_UNICODE *p,
@@ -2619,14 +2647,31 @@
     char *s;
     DWORD mbcssize;
 
+    BOOL usedDefaultChar = FALSE;
+    BOOL *pusedDefaultChar = NULL;
+
+    /* check and handle 'errors' arg */
+    if (errors==NULL || strcmp(errors, "strict")==0)
+        pusedDefaultChar = &usedDefaultChar;
+    else if (strcmp(errors, "ignore")==0 || strcmp(errors, "replace")==0) {
+        ; /* pusedDefaultChar remains NULL */
+    } else
+        return PyErr_Format(PyExc_ValueError,
+                            "mbcs encoding does not support errors='%s'", 
+                            errors);
+
     /* If there are no characters, bail now! */
     if (size==0)
-	    return PyString_FromString("");
+        return PyString_FromString("");
 
     /* First get the size of the result */
-    mbcssize = WideCharToMultiByte(CP_ACP, 0, p, size, NULL, 0, NULL, NULL);
-    if (mbcssize==0)
+    mbcssize = WideCharToMultiByte(CP_ACP, 0, p, size, NULL, 0, 
+                                   NULL, pusedDefaultChar);
+    if (mbcssize==0) /* general failure */
         return PyErr_SetFromWindowsErrWithFilename(0, NULL);
+    /* If we used a default char, then we failed! */
+    if (pusedDefaultChar && *pusedDefaultChar)
+        goto mbcs_encode_error;
 
     repr = PyString_FromStringAndSize(NULL, mbcssize);
     if (repr == NULL)
@@ -2636,11 +2681,27 @@
 
     /* Do the conversion */
     s = PyString_AS_STRING(repr);
-    if (0 == WideCharToMultiByte(CP_ACP, 0, p, size, s, mbcssize, NULL, NULL)) {
+    if (0 == WideCharToMultiByte(CP_ACP, 0, p, size, s, mbcssize, 
+                                 NULL, pusedDefaultChar)) {
         Py_DECREF(repr);
         return PyErr_SetFromWindowsErrWithFilename(0, NULL);
     }
+    if (pusedDefaultChar && *pusedDefaultChar) {
+        Py_DECREF(repr);
+        goto mbcs_encode_error;
+    }
     return repr;
+mbcs_encode_error:
+    /* This is only for encoding error, not Windows errors */
+    {
+        PyObject *exc = NULL;
+        /* Not sure what to use here?  Again, what size to use? */
+        const char *reason = "invalid character";
+        raise_encode_exception(&exc, "mbcs", p, size,
+                               0, 0, reason);
+        Py_XDECREF(exc);
+    }
+    return NULL;
 }
 
 PyObject *PyUnicode_AsMBCSString(PyObject *unicode)