[Python-checkins] bpo-36236: Fix _PyPathConfig_ComputeSysPath0() for empty argv (GH-12441)
Victor Stinner
webhook-mailer at python.org
Tue Mar 19 13:22:59 EDT 2019
https://github.com/python/cpython/commit/fc96e5474a7bda1c5dec66420e4467fc9f7ca968
commit: fc96e5474a7bda1c5dec66420e4467fc9f7ca968
branch: master
author: Victor Stinner <vstinner at redhat.com>
committer: GitHub <noreply at github.com>
date: 2019-03-19T18:22:55+01:00
summary:
bpo-36236: Fix _PyPathConfig_ComputeSysPath0() for empty argv (GH-12441)
* _PyPathConfig_ComputeSysPath0() now returns 0 if argv is empty.
* Cleanup also _PyPathConfig_ComputeSysPath0() code: move variables
definitions closer to where they are used.
files:
M Python/pathconfig.c
diff --git a/Python/pathconfig.c b/Python/pathconfig.c
index 743e1cd1ac0b..0ccb898e4290 100644
--- a/Python/pathconfig.c
+++ b/Python/pathconfig.c
@@ -573,79 +573,84 @@ Py_GetProgramName(void)
Return 1 if the path is correctly resolved, but *path0_p can be NULL
if the Unicode object fail to be created.
- Return 0 if it fails to resolve the full path (and *path0_p will be NULL),
- for example if the current working directory has been removed (bpo-36236).
+ Return 0 if it fails to resolve the full path (and *path0_p will be NULL).
+ For example, return 0 if the current working directory has been removed
+ (bpo-36236) or if argv is empty.
*/
int
_PyPathConfig_ComputeSysPath0(const _PyWstrList *argv, PyObject **path0_p)
{
assert(_PyWstrList_CheckConsistency(argv));
+ assert(*path0_p == NULL);
- wchar_t *argv0;
- wchar_t *p = NULL;
+ if (argv->length == 0) {
+ /* Leave sys.path unchanged if sys.argv is empty */
+ return 0;
+ }
+
+ wchar_t *argv0 = argv->items[0];
+ int have_module_arg = (wcscmp(argv0, L"-m") == 0);
+ int have_script_arg = (!have_module_arg && (wcscmp(argv0, L"-c") != 0));
+
+ wchar_t *path0 = argv0;
Py_ssize_t n = 0;
- int have_script_arg = 0;
- int have_module_arg = 0;
-#ifdef HAVE_READLINK
- wchar_t link[MAXPATHLEN + 1];
- wchar_t argv0copy[2 * MAXPATHLEN + 1];
- int nr = 0;
-#endif
-#if defined(HAVE_REALPATH)
+
+#ifdef HAVE_REALPATH
wchar_t fullpath[MAXPATHLEN];
#elif defined(MS_WINDOWS)
wchar_t fullpath[MAX_PATH];
#endif
- assert(*path0_p == NULL);
-
- if (argv->length > 0) {
- argv0 = argv->items[0];
- have_module_arg = (wcscmp(argv0, L"-m") == 0);
- have_script_arg = !have_module_arg && (wcscmp(argv0, L"-c") != 0);
- }
-
if (have_module_arg) {
#if defined(HAVE_REALPATH) || defined(MS_WINDOWS)
- if (!_Py_wgetcwd(fullpath, Py_ARRAY_LENGTH(fullpath))) {
- *path0_p = NULL;
- return 0;
- }
- argv0 = fullpath;
- n = wcslen(argv0);
+ if (!_Py_wgetcwd(fullpath, Py_ARRAY_LENGTH(fullpath))) {
+ return 0;
+ }
+ path0 = fullpath;
#else
- argv0 = L".";
- n = 1;
+ path0 = L".";
#endif
+ n = wcslen(path0);
}
#ifdef HAVE_READLINK
- if (have_script_arg)
- nr = _Py_wreadlink(argv0, link, Py_ARRAY_LENGTH(link));
+ wchar_t link[MAXPATHLEN + 1];
+ int nr = 0;
+
+ if (have_script_arg) {
+ nr = _Py_wreadlink(path0, link, Py_ARRAY_LENGTH(link));
+ }
if (nr > 0) {
/* It's a symlink */
link[nr] = '\0';
- if (link[0] == SEP)
- argv0 = link; /* Link to absolute path */
- else if (wcschr(link, SEP) == NULL)
- ; /* Link without path */
+ if (link[0] == SEP) {
+ path0 = link; /* Link to absolute path */
+ }
+ else if (wcschr(link, SEP) == NULL) {
+ /* Link without path */
+ }
else {
- /* Must join(dirname(argv0), link) */
- wchar_t *q = wcsrchr(argv0, SEP);
- if (q == NULL)
- argv0 = link; /* argv0 without path */
+ /* Must join(dirname(path0), link) */
+ wchar_t *q = wcsrchr(path0, SEP);
+ if (q == NULL) {
+ /* path0 without path */
+ path0 = link;
+ }
else {
- /* Must make a copy, argv0copy has room for 2 * MAXPATHLEN */
- wcsncpy(argv0copy, argv0, MAXPATHLEN);
- q = wcsrchr(argv0copy, SEP);
+ /* Must make a copy, path0copy has room for 2 * MAXPATHLEN */
+ wchar_t path0copy[2 * MAXPATHLEN + 1];
+ wcsncpy(path0copy, path0, MAXPATHLEN);
+ q = wcsrchr(path0copy, SEP);
wcsncpy(q+1, link, MAXPATHLEN);
q[MAXPATHLEN + 1] = L'\0';
- argv0 = argv0copy;
+ path0 = path0copy;
}
}
}
#endif /* HAVE_READLINK */
+ wchar_t *p = NULL;
+
#if SEP == '\\'
/* Special case for Microsoft filename syntax */
if (have_script_arg) {
@@ -653,43 +658,46 @@ _PyPathConfig_ComputeSysPath0(const _PyWstrList *argv, PyObject **path0_p)
#if defined(MS_WINDOWS)
/* Replace the first element in argv with the full path. */
wchar_t *ptemp;
- if (GetFullPathNameW(argv0,
+ if (GetFullPathNameW(path0,
Py_ARRAY_LENGTH(fullpath),
fullpath,
&ptemp)) {
- argv0 = fullpath;
+ path0 = fullpath;
}
#endif
- p = wcsrchr(argv0, SEP);
+ p = wcsrchr(path0, SEP);
/* Test for alternate separator */
- q = wcsrchr(p ? p : argv0, '/');
+ q = wcsrchr(p ? p : path0, '/');
if (q != NULL)
p = q;
if (p != NULL) {
- n = p + 1 - argv0;
+ n = p + 1 - path0;
if (n > 1 && p[-1] != ':')
n--; /* Drop trailing separator */
}
}
-#else /* All other filename syntaxes */
+#else
+ /* All other filename syntaxes */
if (have_script_arg) {
#if defined(HAVE_REALPATH)
- if (_Py_wrealpath(argv0, fullpath, Py_ARRAY_LENGTH(fullpath))) {
- argv0 = fullpath;
+ if (_Py_wrealpath(path0, fullpath, Py_ARRAY_LENGTH(fullpath))) {
+ path0 = fullpath;
}
#endif
- p = wcsrchr(argv0, SEP);
+ p = wcsrchr(path0, SEP);
}
if (p != NULL) {
- n = p + 1 - argv0;
+ n = p + 1 - path0;
#if SEP == '/' /* Special case for Unix filename syntax */
- if (n > 1)
- n--; /* Drop trailing separator */
+ if (n > 1) {
+ /* Drop trailing separator */
+ n--;
+ }
#endif /* Unix */
}
#endif /* All others */
- *path0_p = PyUnicode_FromWideChar(argv0, n);
+ *path0_p = PyUnicode_FromWideChar(path0, n);
return 1;
}
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