[Python-checkins] r46037 - in python/trunk: Doc/lib/libfuncs.tex Lib/test/test_file.py Misc/NEWS Objects/fileobject.c
georg.brandl
python-checkins at python.org
Thu May 18 09:01:31 CEST 2006
Author: georg.brandl
Date: Thu May 18 09:01:27 2006
New Revision: 46037
Modified:
python/trunk/Doc/lib/libfuncs.tex
python/trunk/Lib/test/test_file.py
python/trunk/Misc/NEWS
python/trunk/Objects/fileobject.c
Log:
Bug #1462152: file() now checks more thoroughly for invalid mode
strings and removes a possible "U" before passing the mode to the
C library function.
Modified: python/trunk/Doc/lib/libfuncs.tex
==============================================================================
--- python/trunk/Doc/lib/libfuncs.tex (original)
+++ python/trunk/Doc/lib/libfuncs.tex Thu May 18 09:01:27 2006
@@ -418,7 +418,7 @@
that differentiate between binary and text files (else it is
ignored). If the file cannot be opened, \exception{IOError} is
raised.
-
+
In addition to the standard \cfunction{fopen()} values \var{mode}
may be \code{'U'} or \code{'rU'}. If Python is built with universal
newline support (the default) the file is opened as a text file, but
@@ -434,6 +434,9 @@
have yet been seen), \code{'\e n'}, \code{'\e r'}, \code{'\e r\e n'},
or a tuple containing all the newline types seen.
+ Python enforces that the mode, after stripping \code{'U'}, begins with
+ \code{'r'}, \code{'w'} or \code{'a'}.
+
If \var{mode} is omitted, it defaults to \code{'r'}. When opening a
binary file, you should append \code{'b'} to the \var{mode} value
for improved portability. (It's useful even on systems which don't
@@ -456,6 +459,9 @@
determine whether this is the case.}
\versionadded{2.2}
+
+ \versionchanged[Restriction on first letter of mode string
+ introduced]{2.5}
\end{funcdesc}
\begin{funcdesc}{filter}{function, list}
Modified: python/trunk/Lib/test/test_file.py
==============================================================================
--- python/trunk/Lib/test/test_file.py (original)
+++ python/trunk/Lib/test/test_file.py Thu May 18 09:01:27 2006
@@ -136,7 +136,7 @@
bad_mode = "qwerty"
try:
open(TESTFN, bad_mode)
-except IOError, msg:
+except ValueError, msg:
if msg[0] != 0:
s = str(msg)
if s.find(TESTFN) != -1 or s.find(bad_mode) == -1:
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS (original)
+++ python/trunk/Misc/NEWS Thu May 18 09:01:27 2006
@@ -12,6 +12,10 @@
Core and builtins
-----------------
+- Bug #1462152: file() now checks more thoroughly for invalid mode
+ strings and removes a possible "U" before passing the mode to the
+ C library function.
+
- Patch #1488312, Fix memory alignment problem on SPARC in unicode
- Bug #1487966: Fix SystemError with conditional expression in assignment
Modified: python/trunk/Objects/fileobject.c
==============================================================================
--- python/trunk/Objects/fileobject.c (original)
+++ python/trunk/Objects/fileobject.c Thu May 18 09:01:27 2006
@@ -136,46 +136,45 @@
/* check for known incorrect mode strings - problem is, platforms are
free to accept any mode characters they like and are supposed to
ignore stuff they don't understand... write or append mode with
- universal newline support is expressly forbidden by PEP 278. */
+ universal newline support is expressly forbidden by PEP 278.
+ Additionally, remove the 'U' from the mode string as platforms
+ won't know what it is. */
/* zero return is kewl - one is un-kewl */
static int
-check_the_mode(char *mode)
+sanitize_the_mode(char *mode)
{
+ char *upos;
size_t len = strlen(mode);
- switch (len) {
- case 0:
+ if (!len) {
PyErr_SetString(PyExc_ValueError, "empty mode string");
return 1;
+ }
- /* reject wU, aU */
- case 2:
- switch (mode[0]) {
- case 'w':
- case 'a':
- if (mode[1] == 'U') {
- PyErr_SetString(PyExc_ValueError,
- "invalid mode string");
- return 1;
- }
- break;
+ upos = strchr(mode, 'U');
+ if (upos) {
+ memmove(upos, upos+1, len-(upos-mode)); /* incl null char */
+
+ if (mode[0] == 'w' || mode[0] == 'a') {
+ PyErr_Format(PyExc_ValueError, "universal newline "
+ "mode can only be used with modes "
+ "starting with 'r'");
+ return 1;
}
- break;
- /* reject w+U, a+U, wU+, aU+ */
- case 3:
- switch (mode[0]) {
- case 'w':
- case 'a':
- if ((mode[1] == '+' && mode[2] == 'U') ||
- (mode[1] == 'U' && mode[2] == '+')) {
- PyErr_SetString(PyExc_ValueError,
- "invalid mode string");
- return 1;
- }
- break;
+ if (mode[0] != 'r') {
+ memmove(mode+1, mode, strlen(mode)+1);
+ mode[0] = 'r';
}
- break;
+
+ if (!strchr(mode, 'b')) {
+ memmove(mode+2, mode+1, strlen(mode));
+ mode[1] = 'b';
+ }
+ } else if (mode[0] != 'r' && mode[0] != 'w' && mode[0] != 'a') {
+ PyErr_Format(PyExc_ValueError, "mode string must begin with "
+ "one of 'r', 'w', 'a' or 'U', not '%.200s'", mode);
+ return 1;
}
return 0;
@@ -184,6 +183,7 @@
static PyObject *
open_the_file(PyFileObject *f, char *name, char *mode)
{
+ char *newmode;
assert(f != NULL);
assert(PyFile_Check(f));
#ifdef MS_WINDOWS
@@ -195,8 +195,18 @@
assert(mode != NULL);
assert(f->f_fp == NULL);
- if (check_the_mode(mode))
+ /* probably need to replace 'U' by 'rb' */
+ newmode = PyMem_MALLOC(strlen(mode) + 3);
+ if (!newmode) {
+ PyErr_NoMemory();
return NULL;
+ }
+ strcpy(newmode, mode);
+
+ if (sanitize_the_mode(newmode)) {
+ f = NULL;
+ goto cleanup;
+ }
/* rexec.py can't stop a user from getting the file() constructor --
all they have to do is get *any* file object f, and then do
@@ -204,16 +214,15 @@
if (PyEval_GetRestricted()) {
PyErr_SetString(PyExc_IOError,
"file() constructor not accessible in restricted mode");
- return NULL;
+ f = NULL;
+ goto cleanup;
}
errno = 0;
- if (strcmp(mode, "U") == 0 || strcmp(mode, "rU") == 0)
- mode = "rb";
#ifdef MS_WINDOWS
if (PyUnicode_Check(f->f_name)) {
PyObject *wmode;
- wmode = PyUnicode_DecodeASCII(mode, strlen(mode), NULL);
+ wmode = PyUnicode_DecodeASCII(newmode, strlen(newmode), NULL);
if (f->f_name && wmode) {
Py_BEGIN_ALLOW_THREADS
/* PyUnicode_AS_UNICODE OK without thread
@@ -227,7 +236,7 @@
#endif
if (NULL == f->f_fp && NULL != name) {
Py_BEGIN_ALLOW_THREADS
- f->f_fp = fopen(name, mode);
+ f->f_fp = fopen(name, newmode);
Py_END_ALLOW_THREADS
}
@@ -254,6 +263,10 @@
}
if (f != NULL)
f = dircheck(f);
+
+cleanup:
+ PyMem_FREE(newmode);
+
return (PyObject *)f;
}
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