MFB: fix #43927 (koi8r is missing from html_entity_decode())

patch by andy at demos dot su

ext/standard/html.c

@@ -958,6 +958,7 @@ PHPAPI char *php_unescape_html_entities(char *orig, int oldlen, int *newlen, int
 					case cs_cp1251:
 					case cs_8859_5:
 					case cs_cp866:
+					case cs_koi8r:
 						replacement[0] = k;
 						replacement[1] = '\0';
 						replacement_len = 1;

ext/standard/tests/strings/bug43927.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Bug #43927 (koi8r is missing from html_entity_decode())
+--FILE--
+<?php
+var_dump(html_entity_decode("&amp;lt;", ENT_COMPAT, 'koi8-r'));
+var_dump(html_entity_decode("&amp;#38;", ENT_COMPAT, 'koi8-r'));
+var_dump(html_entity_decode("&amp;#38;lt;", ENT_COMPAT, 'koi8-r'));
+?>
+--EXPECT--
+string(4) "&lt;"
+string(5) "&#38;"
+string(8) "&#38;lt;"
+--UEXPECT--
+unicode(4) "&lt;"
+unicode(5) "&#38;"
+unicode(8) "&#38;lt;"