Set locale in unit tests

issue #901

tests/unittests/unittests.c

@@ -6,7 +6,9 @@
 #include <setjmp.h>
 #include <cmocka.h>
 #include <sys/stat.h>
+#include <stdlib.h>
 #include <locale.h>
+#include <langinfo.h>
 
 #include "config.h"
 #include "xmpp/chat_session.h"
@@ -38,7 +40,21 @@
 #include "test_plugins_disco.h"
 
 int main(int argc, char* argv[]) {
-    setlocale(LC_ALL, "");
+    setlocale(LC_ALL, "en_GB.UTF-8");
+    char *codeset = nl_langinfo(CODESET);
+    char *lang = getenv("LANG");
+
+    printf("Charset information:\n");
+
+    if (lang) {
+        printf("  LANG:       %s\n", lang);
+    }
+    if (codeset) {
+        printf("  CODESET:    %s\n", codeset);
+    }
+    printf("  MB_CUR_MAX: %d\n", MB_CUR_MAX);
+    printf("  MB_LEN_MAX: %d\n", MB_LEN_MAX);
+
     const UnitTest all_tests[] = {
 
         unit_test(replace_one_substr),