Index: Python/pythonrun.c
===================================================================
--- Python/pythonrun.c	(révision 70384)
+++ Python/pythonrun.c	(copie de travail)
@@ -1890,6 +1890,25 @@
 	err_input(err);
 }
 
+/* Convert the byte index in the UTF-8 string into the character index
+   in the unicode string */
+
+static int
+adjust_offset(PyObject *textobj, int byte_offset)
+{
+	Py_UNICODE *text = PyUnicode_AS_UNICODE(textobj);
+	Py_ssize_t textlen = PyUnicode_GET_SIZE(textobj);
+	int character_offset = 0;
+	Py_ssize_t i;
+	for (i=0; i < textlen; i++, text++) {
+		byte_offset -= _PyUnicode_UTF8Size(*text);
+		if (byte_offset <= 0)
+			break;
+		character_offset++;
+	}
+	return character_offset;
+}
+
 /* Set the error appropriate to the given input error code (see errcode.h) */
 
 static void
@@ -1983,6 +2002,8 @@
 	} else {
 		errtext = PyUnicode_DecodeUTF8(err->text, strlen(err->text),
 					       "replace");
+		if (errtext)
+			err->offset = adjust_offset(errtext, err->offset);
 	}
 	v = Py_BuildValue("(ziiN)", err->filename,
 			  err->lineno, err->offset, errtext);