homepage

I reviewed getpath.diff:
diff -pru Python-2.7/Modules/getpath.c Python-2.7/Modules/getpath.c
--- Python-2.7/Modules/getpath.c
+++ Python-2.7/Modules/getpath.c
@@ -218,7 +218,7 @@ joinpath(char *buffer, char *stuff)
 if (n > MAXPATHLEN)
 Py_FatalError("buffer overflow in getpath.c's joinpath()");
 k = strlen(stuff);
- if (n + k > MAXPATHLEN)
+ if (k > MAXPATHLEN - n)
 k = MAXPATHLEN - n;
 strncpy(buffer+n, stuff, k);
 buffer[n+k] = '0円';
As I explained in a previous comment, this change is useless: "n+k" cannot overflow.
@@ -229,10 +229,9 @@ joinpath(char *buffer, char *stuff)
 static void
 copy_absolute(char *path, char *p)
 {
- if (p[0] == SEP)
+ if (p[0] == SEP || getcwd(path, MAXPATHLEN) == NULL)
 strcpy(path, p);
 else {
- getcwd(path, MAXPATHLEN);
 if (p[0] == '.' && p[1] == SEP)
 p += 2;
 joinpath(path, p);
The code changed in the meanwhile (in the master branch, in 3.7 maybe, I don't recall), getcwd() error is now checked in copy_absolute():
 if (!_Py_wgetcwd(path, pathlen)) {
 /* unable to get the current directory */
 wcscpy(path, p);
 return;
 }
diff -pru Python-3.2a3/Modules/getpath.c Python-3.2a3/Modules/getpath.c
--- Python-3.2a3/Modules/getpath.c
+++ Python-3.2a3/Modules/getpath.c
@@ -351,18 +351,18 @@ search_for_exec_prefix(wchar_t *argv0_pa
 else {
 char buf[MAXPATHLEN+1];
 PyObject *decoded;
- wchar_t rel_builddir_path[MAXPATHLEN+1];
- size_t n;
 n = fread(buf, 1, MAXPATHLEN, f);
 buf[n] = '0円';
 fclose(f);
 decoded = PyUnicode_DecodeUTF8(buf, n, "surrogateescape");
 if (decoded != NULL) {
- n = PyUnicode_AsWideChar((PyUnicodeObject*)decoded,
+ wchar_t rel_builddir_path[MAXPATHLEN+1];
+ Py_ssize_t k;
+ k = PyUnicode_AsWideChar((PyUnicodeObject*)decoded,
 rel_builddir_path, MAXPATHLEN);
 Py_DECREF(decoded);
- if (n >= 0) {
- rel_builddir_path[n] = L'0円';
+ if (k >= 0) {
+ rel_builddir_path[k] = L'0円';
 wcscpy(exec_prefix, argv0_path);
 joinpath(exec_prefix, rel_builddir_path);
 return -1;
Again, the code changed in the meanwhile:
 wchar_t *rel_builddir_path;
 ...
 rel_builddir_path = _Py_DecodeUTF8_surrogateescape(buf, n);
 if (rel_builddir_path) {
There is a new _Py_DecodeUTF8_surrogateescape() function which returns directly wchar_t* strings.
I close the issue.
--
Modules/getpath.c should be rewritten without global MAXPATHLEN limit. I rewrote the code to avoid global variables and pass buffer lengths in some functions. It's better but not perfect yet :-))