1 files changed, 20 insertions, 10 deletions

diff --git a/core/ustring.cpp b/core/ustring.cpp
index 3f017fa985..c1888c87a7 100644
--- a/core/ustring.cpp
+++ b/core/ustring.cpp
@@ -5,8 +5,8 @@
 /*                           GODOT ENGINE                                */
 /*                      https://godotengine.org                          */
 /*************************************************************************/
-/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.                 */
-/* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md)    */
+/* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2019 Godot Engine contributors (cf. AUTHORS.md)    */
 /*                                                                       */
 /* Permission is hereby granted, free of charge, to any person obtaining */
 /* a copy of this software and associated documentation files (the       */
@@ -58,6 +58,9 @@
 #define IS_DIGIT(m_d) ((m_d) >= '0' && (m_d) <= '9')
 #define IS_HEX_DIGIT(m_d) (((m_d) >= '0' && (m_d) <= '9') || ((m_d) >= 'a' && (m_d) <= 'f') || ((m_d) >= 'A' && (m_d) <= 'F'))
 
+const char CharString::_null = 0;
+const CharType String::_null = 0;
+
 bool is_symbol(CharType c) {
 	return c != '_' && ((c >= '!' && c <= '/') || (c >= ':' && c <= '@') || (c >= '[' && c <= '`') || (c >= '{' && c <= '~') || c == '\t' || c == ' ');
 }
@@ -179,7 +182,7 @@ void String::copy_from_unchecked(const CharType *p_char, const int p_length) {
 	resize(p_length + 1);
 	set(p_length, 0);
 
-	CharType *dst = &operator[](0);
+	CharType *dst = ptrw();
 
 	for (int i = 0; i < p_length; i++) {
 		dst[i] = p_char[i];
@@ -250,7 +253,7 @@ String &String::operator+=(const String &p_str) {
 	resize(length() + p_str.size());
 
 	const CharType *src = p_str.c_str();
-	CharType *dst = &operator[](0);
+	CharType *dst = ptrw();
 
 	set(length(), 0);
 
@@ -289,7 +292,7 @@ String &String::operator+=(const char *p_str) {
 
 	resize(from + src_len + 1);
 
-	CharType *dst = &operator[](0);
+	CharType *dst = ptrw();
 
 	set(length(), 0);
 
@@ -1431,7 +1434,7 @@ bool String::parse_utf8(const char *p_utf8, int p_len) {
 	}
 
 	resize(str_size + 1);
-	CharType *dst = &operator[](0);
+	CharType *dst = ptrw();
 	dst[str_size] = 0;
 
 	while (cstr_size) {
@@ -2390,6 +2393,10 @@ int String::find(const char *p_str, int p_from) const {
 	return -1;
 }
 
+int String::find_char(CharType p_char, int p_from) const {
+	return _cowdata.find(p_char, p_from);
+}
+
 int String::findmk(const Vector<String> &p_keys, int p_from, int *r_key) const {
 
 	if (p_from < 0)
@@ -3060,7 +3067,7 @@ String String::lstrip(const String &p_chars) const {
 
 	for (beg = 0; beg < len; beg++) {
 
-		if (p_chars.find(&ptr()[beg]) == -1)
+		if (p_chars.find_char(get(beg)) == -1)
 			break;
 	}
 
@@ -3077,7 +3084,7 @@ String String::rstrip(const String &p_chars) const {
 
 	for (end = len - 1; end >= 0; end--) {
 
-		if (p_chars.find(&ptr()[end]) == -1)
+		if (p_chars.find_char(get(end)) == -1)
 			break;
 	}
 
@@ -3476,7 +3483,7 @@ String String::xml_unescape() const {
 	if (len == 0)
 		return String();
 	str.resize(len + 1);
-	_xml_unescape(c_str(), l, &str[0]);
+	_xml_unescape(c_str(), l, str.ptrw());
 	str[len] = 0;
 	return str;
 }
@@ -3578,9 +3585,12 @@ bool String::is_valid_integer() const {
 
 bool String::is_valid_hex_number(bool p_with_prefix) const {
 
-	int from = 0;
 	int len = length();
 
+	if (len == 0)
+		return false;
+
+	int from = 0;
 	if (len != 1 && (operator[](0) == '+' || operator[](0) == '-'))
 		from++;