bpo-28604: Fix localeconv() for different LC_MONETARY (GH-10606)

locale.localeconv() now sets temporarily the LC_CTYPE locale to the
LC_MONETARY locale if the two locales are different and monetary
strings are non-ASCII. This temporary change affects other threads.

Changes:

* locale.localeconv() can now set LC_CTYPE to LC_MONETARY to decode
  monetary fields.
* Add LocaleInfo.grouping_buffer: copy localeconv() grouping string
  since it can be replaced anytime if a different thread calls
  localeconv().
* _Py_GetLocaleconvNumeric() now requires a "struct lconv *"
  structure, so locale.localeconv() now longer calls localeconv()
  twice. Moreover, the function now requires all arguments to be
  non-NULL.
* Rename STATIC_LOCALE_INFO_INIT to LocaleInfo_STATIC_INIT.
* Move _Py_GetLocaleconvNumeric() definition from fileutils.h
  to pycore_fileutils.h. pycore_fileutils.h now includes locale.h.
* The _locale module is now built with Py_BUILD_CORE defined.

1 files changed, 18 insertions, 27 deletions

diff --git a/Python/fileutils.c b/Python/fileutils.c
index c9a8e58..033c2ff 100644
--- a/Python/fileutils.c
+++ b/Python/fileutils.c
@@ -1868,22 +1868,17 @@ error:
 
 
 int
-_Py_GetLocaleconvNumeric(PyObject **decimal_point, PyObject **thousands_sep,
-                         const char **grouping)
+_Py_GetLocaleconvNumeric(struct lconv *lc,
+                         PyObject **decimal_point, PyObject **thousands_sep)
 {
-    int res = -1;
-
-    struct lconv *lc = localeconv();
+    assert(decimal_point != NULL);
+    assert(thousands_sep != NULL);
 
     int change_locale = 0;
-    if (decimal_point != NULL &&
-        (strlen(lc->decimal_point) > 1 || ((unsigned char)lc->decimal_point[0]) > 127))
-    {
+    if ((strlen(lc->decimal_point) > 1 || ((unsigned char)lc->decimal_point[0]) > 127)) {
         change_locale = 1;
     }
-    if (thousands_sep != NULL &&
-        (strlen(lc->thousands_sep) > 1 || ((unsigned char)lc->thousands_sep[0]) > 127))
-    {
+    if ((strlen(lc->thousands_sep) > 1 || ((unsigned char)lc->thousands_sep[0]) > 127)) {
         change_locale = 1;
     }
 
@@ -1892,7 +1887,8 @@ _Py_GetLocaleconvNumeric(PyObject **decimal_point, PyObject **thousands_sep,
     if (change_locale) {
         oldloc = setlocale(LC_CTYPE, NULL);
         if (!oldloc) {
-            PyErr_SetString(PyExc_RuntimeWarning, "faild to get LC_CTYPE locale");
+            PyErr_SetString(PyExc_RuntimeWarning,
+                            "failed to get LC_CTYPE locale");
             return -1;
         }
 
@@ -1908,7 +1904,7 @@ _Py_GetLocaleconvNumeric(PyObject **decimal_point, PyObject **thousands_sep,
         }
 
         if (loc != NULL) {
-            /* Only set the locale temporarilty the LC_CTYPE locale
+            /* Only set the locale temporarily the LC_CTYPE locale
                if LC_NUMERIC locale is different than LC_CTYPE locale and
                decimal_point and/or thousands_sep are non-ASCII or longer than
                1 byte */
@@ -1916,26 +1912,21 @@ _Py_GetLocaleconvNumeric(PyObject **decimal_point, PyObject **thousands_sep,
         }
     }
 
-    if (decimal_point != NULL) {
-        *decimal_point = PyUnicode_DecodeLocale(lc->decimal_point, NULL);
-        if (*decimal_point == NULL) {
-            goto error;
-        }
-    }
-    if (thousands_sep != NULL) {
-        *thousands_sep = PyUnicode_DecodeLocale(lc->thousands_sep, NULL);
-        if (*thousands_sep == NULL) {
-            goto error;
-        }
+    int res = -1;
+
+    *decimal_point = PyUnicode_DecodeLocale(lc->decimal_point, NULL);
+    if (*decimal_point == NULL) {
+        goto done;
     }
 
-    if (grouping != NULL) {
-        *grouping = lc->grouping;
+    *thousands_sep = PyUnicode_DecodeLocale(lc->thousands_sep, NULL);
+    if (*thousands_sep == NULL) {
+        goto done;
     }
 
     res = 0;
 
-error:
+done:
     if (loc != NULL) {
         setlocale(LC_CTYPE, oldloc);
     }