Use locale::LOCALE_LOCK for all setlocale() calls

I had originally created a safe `set_locale()` wrapper and clippy-disallowed
`libc::setlocale()` but almost all our uses of `libc::setlocale()` are in a loop
where it makes much more sense to just obtain the lock outright then call
`setlocale()` repeatedly rather than lock it in the wrapper function each time.

src/env_dispatch.rs

@@ -678,6 +678,8 @@ fn init_curses(vars: &EnvStack) {
 
 /// Initialize the locale subsystem
 fn init_locale(vars: &EnvStack) {
+    let _guard = crate::locale::LOCALE_LOCK.lock().unwrap();
+
     #[rustfmt::skip]
     const UTF8_LOCALES: &[&str] = &[
         "C.UTF-8", "en_US.UTF-8", "en_GB.UTF-8", "de_DE.UTF-8", "C.utf8", "UTF-8",

src/locale.rs

@@ -2,6 +2,9 @@
 pub use printf_compat::locale::{Locale, C_LOCALE};
 use std::sync::Mutex;
 
+/// Lock guarding libc `setlocale()` or `localeconv()` calls to avoid races.
+pub(crate) static LOCALE_LOCK: Mutex<()> = Mutex::new(());
+
 /// It's CHAR_MAX.
 const CHAR_MAX: libc::c_char = libc::c_char::max_value();
 
@@ -102,7 +105,7 @@ unsafe fn read_locale() -> Option<Locale> {
 unsafe fn read_locale() -> Option<Locale> {
     // Bleh, we have to go through localeconv, which races with setlocale.
     // TODO: There has to be a better way to do this.
-    let _guard = SETLOCALE_LOCK.lock().unwrap();
+    let _guard = LOCALE_LOCK.lock().unwrap();
     const empty: [libc::c_char; 1] = [0];
     const c_loc_str: [libc::c_char; 2] = [b'C' as libc::c_char, 0];
 
@@ -122,10 +125,6 @@ unsafe fn read_locale() -> Option<Locale> {
 // Current numeric locale.
 static NUMERIC_LOCALE: Mutex<Option<Locale>> = Mutex::new(None);
 
-/// Lock guarding setlocale() calls to avoid races.
-// TODO: need to grab this lock when we port setlocale() calls.
-static SETLOCALE_LOCK: Mutex<()> = Mutex::new(());
-
 pub fn get_numeric_locale() -> Locale {
     let mut locale = NUMERIC_LOCALE.lock().unwrap();
     if locale.is_none() {

src/tests/string_escape.rs

@@ -2,16 +2,15 @@ use crate::common::{
     escape_string, str2wcstring, unescape_string, wcs2string, EscapeFlags, EscapeStringStyle,
     UnescapeStringStyle, ENCODE_DIRECT_BASE, ENCODE_DIRECT_END,
 };
+use crate::locale::LOCALE_LOCK;
 use crate::wchar::{wstr, WString, L};
 use crate::wutil::encoding::{wcrtomb, zero_mbstate, AT_LEAST_MB_LEN_MAX};
 use rand::{Rng, RngCore};
 use rand_pcg::Pcg64Mcg;
-use std::sync::Mutex;
 
 /// wcs2string is locale-dependent, so ensure we have a multibyte locale
 /// before using it in a test.
 fn setlocale() {
-    static LOCALE_LOCK: Mutex<()> = Mutex::new(());
     let _guard = LOCALE_LOCK.lock().unwrap();
 
     #[rustfmt::skip]