Merge branch 'PHP-5.6' into PHP-7.0

* PHP-5.6:
  Fix Bug #72992 mbstring.internal_encoding doesn't inherit default_charset

diff --cc ext/mbstring/mbstring.c
index baec14c70c0785bada9182e6588740ef38477bc4,024da7d32b0836566046a7f71a6ed278431c8471..5524b4180d6151c31156828c47331419a68a8c7c
--- 1/ext/mbstring/mbstring.c
--- 2/ext/mbstring/mbstring.c
+++ b/ext/mbstring/mbstring.c
@@@ -1250,7 -1260,7 +1250,7 @@@ static PHP_INI_MH(OnUpdate_mbstring_htt
        const mbfl_encoding **list;
        size_t size;
  
-       if (!new_value) {
 -      if (!new_value || !new_value_length) {
++      if (!new_value || !ZSTR_VAL(new_value)) {
                if (MBSTRG(http_input_list)) {
                        pefree(MBSTRG(http_input_list), 1);
                }