diff --git a/NEWS b/NEWS
index 3e5b23c4d2e..12a6eb7fb9c 100644
--- a/NEWS
+++ b/NEWS
@@ -38,4 +38,7 @@ PHP                                                                        NEWS
   . Fixed bug #76737 (Unserialized reflection objects are broken, they
     shouldn't be serializable). (Nikita)
 
+- Tidy:
+  . Added TIDY_TAG_* constants for HTML5 elements. (cmb)
+
 <<< NOTE: Insert NEWS from last stable release here prior to actual release! >>>
diff --git a/UPGRADING b/UPGRADING
index caebb748ea2..55c20452eab 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -122,6 +122,36 @@ PHP 7.4 UPGRADE NOTES
 10. New Global Constants
 ========================================
 
+- Tidy:
+  . TIDY_TAG_ARTICLE
+  . TIDY_TAG_ASIDE
+  . TIDY_TAG_AUDIO
+  . TIDY_TAG_BDI
+  . TIDY_TAG_CANVAS
+  . TIDY_TAG_COMMAND
+  . TIDY_TAG_DATALIST
+  . TIDY_TAG_DETAILS
+  . TIDY_TAG_DIALOG
+  . TIDY_TAG_FIGCAPTION
+  . TIDY_TAG_FIGURE
+  . TIDY_TAG_FOOTER
+  . TIDY_TAG_HEADER
+  . TIDY_TAG_HGROUP
+  . TIDY_TAG_MAIN
+  . TIDY_TAG_MARK
+  . TIDY_TAG_MENUITEM
+  . TIDY_TAG_METER
+  . TIDY_TAG_NAV
+  . TIDY_TAG_OUTPUT
+  . TIDY_TAG_PROGRESS
+  . TIDY_TAG_SECTION
+  . TIDY_TAG_SOURCE
+  . TIDY_TAG_SUMMARY
+  . TIDY_TAG_TEMPLATE
+  . TIDY_TAG_TIME
+  . TIDY_TAG_TRACK
+  . TIDY_TAG_VIDEO
+
 ========================================
 11. Changes to INI File Handling
 ========================================
diff --git a/ext/opcache/Optimizer/zend_func_info.c b/ext/opcache/Optimizer/zend_func_info.c
index f89e8c79468..8e590b95e95 100644
--- a/ext/opcache/Optimizer/zend_func_info.c
+++ b/ext/opcache/Optimizer/zend_func_info.c
@@ -606,6 +606,7 @@ static const func_info_t func_infos[] = {
 	F0("is_scalar",                    MAY_BE_NULL | MAY_BE_FALSE | MAY_BE_TRUE),
 	F0("is_callable",                  MAY_BE_NULL | MAY_BE_FALSE | MAY_BE_TRUE),
 	F0("is_countable",                 MAY_BE_NULL | MAY_BE_FALSE | MAY_BE_TRUE),
+	F0("is_iterable",                  MAY_BE_NULL | MAY_BE_FALSE | MAY_BE_TRUE),
 	F0("pclose",                       MAY_BE_FALSE | MAY_BE_LONG),
 	F1("popen",                        MAY_BE_NULL | MAY_BE_FALSE | MAY_BE_RESOURCE),
 	F0("readfile",                     MAY_BE_FALSE | MAY_BE_LONG),
diff --git a/ext/standard/string.c b/ext/standard/string.c
index 2f20d62a748..b28ad050d7b 100644
--- a/ext/standard/string.c
+++ b/ext/standard/string.c
@@ -2415,52 +2415,53 @@ PHP_FUNCTION(substr)
 		Z_PARAM_LONG(l)
 	ZEND_PARSE_PARAMETERS_END();
 
-	if (argc > 2) {
-		if ((l < 0 && (size_t)(-l) > ZSTR_LEN(str))) {
-			RETURN_FALSE;
-		} else if (l > (zend_long)ZSTR_LEN(str)) {
-			l = ZSTR_LEN(str);
+	if (f > (zend_long)ZSTR_LEN(str)) {
+		RETURN_FALSE;
+	} else if (f < 0) {
+		/* if "from" position is negative, count start position from the end
+		 * of the string
+		 */
+		if ((size_t)-f > ZSTR_LEN(str)) {
+			f = 0;
+		} else {
+			f = (zend_long)ZSTR_LEN(str) + f;
+		}
+		if (argc > 2) {
+			if (l < 0) {
+				/* if "length" position is negative, set it to the length
+				 * needed to stop that many chars from the end of the string
+				 */
+				if ((size_t)(-l) > ZSTR_LEN(str) - (size_t)f) {
+					if ((size_t)(-l) > ZSTR_LEN(str)) {
+						RETURN_FALSE;
+					} else {
+						l = 0;
+					}
+				} else {
+					l = (zend_long)ZSTR_LEN(str) - f + l;
+				}
+			} else if ((size_t)l > ZSTR_LEN(str) - (size_t)f) {
+				goto truncate_len;
+			}
+		} else {
+			goto truncate_len;
+		}
+	} else if (argc > 2) {
+		if (l < 0) {
+			/* if "length" position is negative, set it to the length
+			 * needed to stop that many chars from the end of the string
+			 */
+			if ((size_t)(-l) > ZSTR_LEN(str) - (size_t)f) {
+				RETURN_FALSE;
+			} else {
+				l = (zend_long)ZSTR_LEN(str) - f + l;
+			}
+		} else if ((size_t)l > ZSTR_LEN(str) - (size_t)f) {
+			goto truncate_len;
 		}
 	} else {
-		l = ZSTR_LEN(str);
-	}
-
-	if (f > (zend_long)ZSTR_LEN(str)) {
-		RETURN_FALSE;
-	} else if (f < 0 && (size_t)-f > ZSTR_LEN(str)) {
-		f = 0;
-	}
-
-	if (l < 0 && (l + (zend_long)ZSTR_LEN(str) - f) < 0) {
-		RETURN_FALSE;
-	}
-
-	/* if "from" position is negative, count start position from the end
-	 * of the string
-	 */
-	if (f < 0) {
-		f = (zend_long)ZSTR_LEN(str) + f;
-		if (f < 0) {
-			f = 0;
-		}
-	}
-
-	/* if "length" position is negative, set it to the length
-	 * needed to stop that many chars from the end of the string
-	 */
-	if (l < 0) {
-		l = ((zend_long)ZSTR_LEN(str) - f) + l;
-		if (l < 0) {
-			l = 0;
-		}
-	}
-
-	if (f > (zend_long)ZSTR_LEN(str)) {
-		RETURN_FALSE;
-	}
-
-	if ((size_t)l > ZSTR_LEN(str) - (size_t)f) {
-		l = ZSTR_LEN(str) - f;
+truncate_len:
+		l = (zend_long)ZSTR_LEN(str) - f;
 	}
 
 	if (l == 0) {
diff --git a/ext/tidy/tidy.c b/ext/tidy/tidy.c
index 0fde23cb11b..9cb63a0d4d3 100644
--- a/ext/tidy/tidy.c
+++ b/ext/tidy/tidy.c
@@ -2021,6 +2021,36 @@ static void _php_tidy_register_tags(INIT_FUNC_ARGS)
 	TIDY_TAG_CONST(VAR);
 	TIDY_TAG_CONST(WBR);
 	TIDY_TAG_CONST(XMP);
+# if HAVE_TIDYBUFFIO_H
+	TIDY_TAG_CONST(ARTICLE);
+	TIDY_TAG_CONST(ASIDE);
+	TIDY_TAG_CONST(AUDIO);
+	TIDY_TAG_CONST(BDI);
+	TIDY_TAG_CONST(CANVAS);
+	TIDY_TAG_CONST(COMMAND);
+	TIDY_TAG_CONST(DATALIST);
+	TIDY_TAG_CONST(DETAILS);
+	TIDY_TAG_CONST(DIALOG);
+	TIDY_TAG_CONST(FIGCAPTION);
+	TIDY_TAG_CONST(FIGURE);
+	TIDY_TAG_CONST(FOOTER);
+	TIDY_TAG_CONST(HEADER);
+	TIDY_TAG_CONST(HGROUP);
+	TIDY_TAG_CONST(MAIN);
+	TIDY_TAG_CONST(MARK);
+	TIDY_TAG_CONST(MENUITEM);
+	TIDY_TAG_CONST(METER);
+	TIDY_TAG_CONST(NAV);
+	TIDY_TAG_CONST(OUTPUT);
+	TIDY_TAG_CONST(PROGRESS);
+	TIDY_TAG_CONST(SECTION);
+	TIDY_TAG_CONST(SOURCE);
+	TIDY_TAG_CONST(SUMMARY);
+	TIDY_TAG_CONST(TEMPLATE);
+	TIDY_TAG_CONST(TIME);
+	TIDY_TAG_CONST(TRACK);
+	TIDY_TAG_CONST(VIDEO);
+# endif
 }
 
 #endif
diff --git a/ext/xml/compat.c b/ext/xml/compat.c
index 012e6b134bc..e5db4469dc3 100644
--- a/ext/xml/compat.c
+++ b/ext/xml/compat.c
@@ -359,7 +359,10 @@ _external_entity_ref_handler(void *user, const xmlChar *names, int type, const x
 		return;
 	}
 
-	parser->h_external_entity_ref(parser, names, (XML_Char *) "", sys_id, pub_id);
+	if (!parser->h_external_entity_ref(parser, names, (XML_Char *) "", sys_id, pub_id)) {
+		xmlStopParser(parser->parser);
+		parser->parser->errNo = XML_ERROR_EXTERNAL_ENTITY_HANDLING;
+	};
 }
 
 static xmlEntityPtr
diff --git a/ext/xml/tests/bug71592.phpt b/ext/xml/tests/bug71592.phpt
new file mode 100644
index 00000000000..28a316a28ee
--- /dev/null
+++ b/ext/xml/tests/bug71592.phpt
@@ -0,0 +1,30 @@
+--TEST--
+Bug #71592 (External entity processing never fails)
+--SKIPIF--
+<?php
+if (!extension_loaded('xml')) die('skip xml extension not available');
+?>
+--FILE--
+<?php
+$xml = <<<XML
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE p [
+  <!ENTITY pic PUBLIC "image.gif" "http://example.org/image.gif">
+]>
+<root>
+<p>&pic;</p>
+<p></nop>
+</root>
+XML;
+
+$parser = xml_parser_create_ns('UTF-8');
+xml_set_external_entity_ref_handler($parser, function () {
+    return false;
+});
+xml_parse($parser, $xml);
+var_dump(xml_get_error_code($parser));
+?>
+===DONE===
+--EXPECT--
+int(21)
+===DONE===