Restore line in newlocale.c that was lost in #4813 (#13584)

When musl was last upgraded this malloc line removed from newlocale.c,
perhaps by accident.

This restores the behaviour of musl which is to allow `newlocale` with
arbitrary names to succeed.  I verified that this is the case using musl
on my desktop.

The reason that test_locale_wrong was passing prior to #4813 is that
the musl older version of musl we were using prior to #4813 rejected
all locales except for "C" and "POSIX".

Upstream version that we are currently based on:
https://github.com/emscripten-core/musl/blob/v1.1.15/src/locale/newlocale.c#L44

Upstream version of musl that we were previously using:
https://github.com/emscripten-core/musl/blob/0b44a0315b47dd8eced9f3b7f31580cf14bbfc01/src/locale/newlocale.c#L5

Author: sbc100

ChangeLog.md

@@ -20,6 +20,9 @@ See docs/process.md for more on how version tagging works.
 
 Current Trunk
 -------------
+- Calls to `newlocale` (and `new std::locale` in C++) with arbirary names will
+  now succeed.  This is the behaviour of musl libc which emscripten had
+  previously inadvertently disabled.
 - System libraries are now compiled with debug info (`-g`).  This doesn't
   affect release builds (builds without `-g`) but allows DWARF debugging of
   types defined in system libraries such as C++ STL types (#13078).

system/lib/libc/musl/src/locale/newlocale.c

@@ -41,6 +41,8 @@ locale_t __newlocale(int mask, const char *name, locale_t loc)
 	if (j==1 && tmp.cat[LC_CTYPE]==&__c_dot_utf8)
 		return UTF8_LOCALE;
 
+	if ((loc = malloc(sizeof *loc))) *loc = tmp;
+
 	return loc;
 }
 

tests/test_locale.c renamed to tests/core/test_localeconv.c

@@ -0,0 +1,16 @@
+#include <locale.h>
+#include <stdio.h>
+
+void test(const char* name) {
+  locale_t loc = newlocale(LC_ALL_MASK, name, 0);
+  if (loc)
+    printf("newlocale '%s' succeeded\n", name);
+  else
+    printf("newlocale '%s' failed\n", name);
+}
+
+int main(int argc, char* argv[]) {
+  test("C");
+  test("waka");
+  return 0;
+}

tests/test_locale.out renamed to tests/core/test_localeconv.out

@@ -0,0 +1,2 @@
+newlocale 'C' succeeded
+newlocale 'waka' succeeded

tests/core/test_newlocale.c

@@ -0,0 +1,11 @@
+#include <stdio.h>
+#include <locale.h>
+
+int main(int argc, char* argv[]) {
+  char* rtn;
+  rtn = setlocale(LC_ALL, "C");
+  printf("done setlocale 'C': '%s'\n", rtn);
+  rtn = setlocale(LC_ALL, "waka");
+  printf("done setlocale 'waka': '%s'\n", rtn);
+  return 0;
+}

tests/core/test_newlocale.out

@@ -0,0 +1,2 @@
+done setlocale 'C': 'C;C;C;C;C;C'
+done setlocale 'waka': 'waka;waka;waka;waka;waka;waka'

tests/core/test_setlocale.c

@@ -7295,8 +7295,14 @@ def test_noexitruntime(self):
   def test_minmax(self):
     self.do_runf(path_from_root('tests', 'test_minmax.c'), 'NAN != NAN\nSuccess!')
 
-  def test_locale(self):
-    self.do_run_in_out_file_test('tests', 'test_locale.c')
+  def test_localeconv(self):
+    self.do_run_in_out_file_test('tests', 'core', 'test_localeconv.c')
+
+  def test_newlocale(self):
+    self.do_run_in_out_file_test('tests', 'core', 'test_newlocale.c')
+
+  def test_setlocale(self):
+    self.do_run_in_out_file_test('tests', 'core', 'test_setlocale.c')
 
   def test_vswprintf_utf8(self):
     self.do_run_in_out_file_test('tests', 'vswprintf_utf8.c')

tests/core/test_setlocale.out

@@ -4679,8 +4679,16 @@ def test_locale_wrong(self):
 }
 ''')
     self.run_process([EMCC, 'src.cpp', '-s', 'EXIT_RUNTIME', '-s', 'DISABLE_EXCEPTION_CATCHING=0'])
-    self.assertContained('Constructed locale "C"\nThis locale is the global locale.\nThis locale is the C locale.', self.run_js('a.out.js', args=['C']))
-    self.assertContained('''Can't construct locale "waka": collate_byname<char>::collate_byname failed to construct for waka''', self.run_js('a.out.js', args=['waka'], assert_returncode=1))
+    self.assertContained('''\
+Constructed locale "C"
+This locale is the global locale.
+This locale is the C locale.
+''', self.run_js('a.out.js', args=['C']))
+    self.assertContained('''\
+Constructed locale "waka"
+This locale is not the global locale.
+This locale is not the C locale.
+''', self.run_js('a.out.js', args=['waka']))
 
   def test_cleanup_os(self):
     # issue 2644