Dynamically allocate path name buffer for Unicode

path name in listdir. Fixes #1431582.
Stop overallocating MAX_PATH characters for ANSI
path names. Stop assigning to errno.

diff --git a/Misc/NEWS b/Misc/NEWS
index bc0f379da6eb9bfda5b7fa3ad5fd575560701edb..a7269afab9964016abf59efca9b383f99696b108 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -72,6 +72,9 @@ Core and builtins
 Extension Modules
 -----------------
 
+- On Win32, os.listdir now supports arbitrarily-long Unicode path names 
+  (up to the system limit of 32K characters).
+
 - Use Win32 API to implement os.{access,chdir,chmod,mkdir,remove,rename,rmdir,utime}.
   As a result, these functions now raise WindowsError instead of OSError.
 

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index bce73a6f569df1aaa03849dbe0b6abf08a3742ac..05481f82d88b503d18eaeffd580305ea503c5633 100644 (file)
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -1782,37 +1782,46 @@ posix_listdir(PyObject *self, PyObject *args)
        HANDLE hFindFile;
        BOOL result;
        WIN32_FIND_DATA FileData;
-       /* MAX_PATH characters could mean a bigger encoded string */
-       char namebuf[MAX_PATH*2+5];
+       char namebuf[MAX_PATH+5]; /* Overallocate for \\*.*\0 */
        char *bufptr = namebuf;
-       Py_ssize_t len = sizeof(namebuf)/sizeof(namebuf[0]);
+       Py_ssize_t len = sizeof(namebuf)-5; /* only claim to have space for MAX_PATH */
 
 #ifdef Py_WIN_WIDE_FILENAMES
        /* If on wide-character-capable OS see if argument
           is Unicode and if so use wide API.  */
        if (unicode_file_names()) {
-               PyUnicodeObject *po;
+               PyObject *po;
                if (PyArg_ParseTuple(args, "U:listdir", &po)) {
                        WIN32_FIND_DATAW wFileData;
-                       Py_UNICODE wnamebuf[MAX_PATH*2+5];
+                       Py_UNICODE *wnamebuf;
                        Py_UNICODE wch;
-                       wcsncpy(wnamebuf, PyUnicode_AS_UNICODE(po), MAX_PATH);
-                       wnamebuf[MAX_PATH] = L'\0';
-                       len = wcslen(wnamebuf);
-                       wch = (len > 0) ? wnamebuf[len-1] : L'\0';
+                       /* Overallocate for \\*.*\0 */
+                       len = PyUnicode_GET_SIZE(po);
+                       wnamebuf = malloc((len + 5) * sizeof(wchar_t));
+                       if (!wnamebuf) {
+                               PyErr_NoMemory();
+                               return NULL;
+                       }
+                       wcscpy(wnamebuf, PyUnicode_AS_UNICODE(po));
+                       wch = len > 0 ? wnamebuf[len-1] : '\0';
                        if (wch != L'/' && wch != L'\\' && wch != L':')
-                               wnamebuf[len++] = L'/';
+                               wnamebuf[len++] = L'\\';
                        wcscpy(wnamebuf + len, L"*.*");
-                       if ((d = PyList_New(0)) == NULL)
+                       if ((d = PyList_New(0)) == NULL) {
+                               free(wnamebuf);
                                return NULL;
+                       }
                        hFindFile = FindFirstFileW(wnamebuf, &wFileData);
                        if (hFindFile == INVALID_HANDLE_VALUE) {
-                               errno = GetLastError();
-                               if (errno == ERROR_FILE_NOT_FOUND) {
+                               int error = GetLastError();
+                               if (error == ERROR_FILE_NOT_FOUND) {
+                                       free(wnamebuf);
                                        return d;
                                }
                                Py_DECREF(d);
-                               return win32_error_unicode("FindFirstFileW", wnamebuf);
+                               win32_error_unicode("FindFirstFileW", wnamebuf);
+                               free(wnamebuf);
+                               return NULL;
                        }
                        do {
                                /* Skip over . and .. */
@@ -1839,7 +1848,9 @@ posix_listdir(PyObject *self, PyObject *args)
 
                        if (FindClose(hFindFile) == FALSE) {
                                Py_DECREF(d);
-                               return win32_error_unicode("FindClose", wnamebuf);
+                               win32_error_unicode("FindClose", wnamebuf);
+                               free(wnamebuf);
+                               return NULL;
                        }
                        return d;
                }
@@ -1864,8 +1875,8 @@ posix_listdir(PyObject *self, PyObject *args)
 
        hFindFile = FindFirstFile(namebuf, &FileData);
        if (hFindFile == INVALID_HANDLE_VALUE) {
-               errno = GetLastError();
-               if (errno == ERROR_FILE_NOT_FOUND)
+               int error = GetLastError();
+               if (error == ERROR_FILE_NOT_FOUND)
                        return d;
                Py_DECREF(d);
                return win32_error("FindFirstFile", namebuf);