Fix up locale handling

src/core/threadcontext.c

@@ -57,11 +57,9 @@ MVMThreadContext * MVM_tc_create(MVMThreadContext *parent, MVMInstance *instance
     /* Initialize plugin_guard_args so we never have to do a NULL check */
     tc->plugin_guard_args = instance->VMNull;
 
-    /* Initialize state related to locales on UNIX-like OSes. Windows doesn't
-     * need this because it doesn't support setting UTF-8 as the locale;
-     * transcoding between wide strings and UTF-8 strings and vice versa is
-     * handled differently from how you'd normally do it on other OSes. */
 #ifndef _MSC_VER
+    /* Initialize state related to locales on UNIX-like OSes. Windows doesn't
+     * need this because its locale support blows and doesn't support UTF-8. */
     tc->mbstate = (mbstate_t){ 0 };
     tc->locale  = duplocale(instance->locale);
 #endif
@@ -118,6 +116,11 @@ void MVM_tc_destroy(MVMThreadContext *tc) {
         MVM_free(tc->temp_bigints[i]);
     }
 
+#ifndef _MSC_VER
+    /* Free our thread's locale. */
+    freelocale(tc->locale);
+#endif
+
     /* Free the thread context itself. */
     memset(tc, 0, sizeof(MVMThreadContext));
     MVM_free(tc);

src/core/threads.c

@@ -69,11 +69,8 @@ static void start_thread(void *data) {
     ThreadStart *ts = (ThreadStart *)data;
     MVMThreadContext *tc = ts->tc;
 
-    /* Set up the thread's locale. This is not important on Windows since its
-     * locale support blows and doesn't allow setting it to UTF-8. We handle
-     * transcoding wide strings to UTF-8 strings and vice versa in a different
-     * way from how you'd do it on other OSes on Windows. */
 #ifndef _MSC_VER
+    /* Use the locale created by our thread context. */
     uselocale(tc->locale);
 #endif
 
@@ -106,11 +103,6 @@ static void start_thread(void *data) {
     /* Mark as exited, so the GC will know to clear our stuff. */
     tc->thread_obj->body.stage = MVM_thread_stage_exited;
 
-    /* Clean up this thread's locale. */
-#ifndef _MSC_VER
-    freelocale(tc->locale);
-#endif
-
     /* Mark ourselves as blocked, so that another thread will take care
      * of GC-ing our objects and cleaning up our thread context. */
     MVM_gc_mark_thread_blocked(tc);

src/moar.c

@@ -85,7 +85,7 @@ MVMInstance * MVM_vm_create_instance(void) {
     /* Set up instance data structure. */
     instance = MVM_calloc(1, sizeof(MVMInstance));
 
-#ifndef _WIN32
+#ifndef _MSC_VER
     /* Set up instance locale. */
     instance->locale = newlocale(LC_CTYPE_MASK, "en_US.UTF-8", (locale_t)0);
 #endif
@@ -647,8 +647,10 @@ void MVM_vm_destroy_instance(MVMInstance *instance) {
     /* Clean up fixed size allocator */
     MVM_fixed_size_destroy(instance->fsa);
 
+#ifndef _MSC_VER
     /* Clean up locale. */
-    MVM_free(instance->locale);
+    freelocale(instance->locale);
+#endif
 
     /* Clear up VM instance memory. */
     MVM_free(instance);