From 29de485a466327433ec7fe2ab9db67a1820534df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kacper=20Piwi=C5=84ski?= <cosiekvfj@o2.pl>
Date: Mon, 16 Dec 2019 22:43:40 +0100
Subject: [PATCH] unescape Backslash char in UTF8 unescape method

---
 CONTRIBUTORS                                |  1 +
 Foundation/src/UTF8String.cpp               | 79 +++++++++++++--------
 Foundation/testsuite/src/UTF8StringTest.cpp |  2 +
 3 files changed, 54 insertions(+), 28 deletions(-)

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 7a74a9cc0..102a4a299 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -50,3 +50,4 @@ Jeff Adams
 Martin Osborne
 Björn Schramke
 Francis Andre
+Kacper Piwiński
diff --git a/Foundation/src/UTF8String.cpp b/Foundation/src/UTF8String.cpp
index e5020695a..d9336f3b2 100644
--- a/Foundation/src/UTF8String.cpp
+++ b/Foundation/src/UTF8String.cpp
@@ -32,11 +32,11 @@ namespace
 
 
 int UTF8::icompare(const std::string& str, std::string::size_type pos, std::string::size_type n, std::string::const_iterator it2, std::string::const_iterator end2)
-{	
+{
 	std::string::size_type sz = str.size();
 	if (pos > sz) pos = sz;
 	if (pos + n > sz) n = sz - pos;
-	TextIterator uit1(str.begin() + pos, str.begin() + pos + n, utf8); 
+	TextIterator uit1(str.begin() + pos, str.begin() + pos + n, utf8);
 	TextIterator uend1(str.begin() + pos + n);
 	TextIterator uit2(it2, end2, utf8);
 	TextIterator uend2(end2);
@@ -50,7 +50,7 @@ int UTF8::icompare(const std::string& str, std::string::size_type pos, std::stri
             return 1;
         ++uit1; ++uit2;
 	}
-    
+
     if (uit1 == uend1)
 		return uit2 == uend2 ? 0 : -1;
     else
@@ -162,9 +162,9 @@ std::string& UTF8::toLowerInPlace(std::string& str)
 
 void UTF8::removeBOM(std::string& str)
 {
-	if (str.size() >= 3 
-		&& static_cast<unsigned char>(str[0]) == 0xEF 
-		&& static_cast<unsigned char>(str[1]) == 0xBB 
+	if (str.size() >= 3
+		&& static_cast<unsigned char>(str[0]) == 0xEF
+		&& static_cast<unsigned char>(str[1]) == 0xBB
 		&& static_cast<unsigned char>(str[2]) == 0xBF)
 	{
 		str.erase(0, 3);
@@ -264,42 +264,74 @@ std::string UTF8::unescape(const std::string::const_iterator& begin, const std::
 				//Invalid sequence!
 			}
 
-			if (*it == 'n')
+			switch (*it)
+			{
+			case 'U':
+			{
+				char digs[9];
+				std::memset(digs, 0, 9);
+				unsigned int dno = 0;
+
+				it++;
+				while (it != end && Ascii::isHexDigit(*it) && dno < 8)
+				{
+					digs[dno++] = *it++;
+				}
+				if (dno > 0)
+				{
+					ch = std::strtol(digs, NULL, 16);
+				}
+				break;
+			}
+			case '\\':
+			{
+				ch = '\\';
+				it++;
+				break;
+			}
+			case 'n':
 			{
 				ch = '\n';
 				it++;
+				break;
 			}
-			else if (*it == 't')
+			case 't':
 			{
 				ch = '\t';
 				it++;
+				break;
 			}
-			else if (*it == 'r')
+			case 'r':
 			{
 				ch = '\r';
 				it++;
+				break;
 			}
-			else if (*it == 'b')
+			case 'b':
 			{
 				ch = '\b';
 				it++;
+				break;
 			}
-			else if (*it == 'f')
+			case 'f':
 			{
 				ch = '\f';
 				it++;
+				break;
 			}
-			else if (*it == 'v')
+			case 'v':
 			{
 				ch = '\v';
 				it++;
+				break;
 			}
-			else if (*it == 'a')
+			case 'a':
 			{
 				ch = '\a';
 				it++;
+				break;
 			}
-			else if (*it == 'u')
+			case 'u':
 			{
 				char digs[5];
 				std::memset(digs, 0, 5);
@@ -345,23 +377,14 @@ std::string UTF8::unescape(const std::string::const_iterator& begin, const std::
 						}
 					}
 				}
+				break;
 			}
-			else if (*it == 'U')
+			default:
 			{
-				char digs[9];
-				std::memset(digs, 0, 9);
-				unsigned int dno = 0;
-
-				it++;
-				while (it != end && Ascii::isHexDigit(*it) && dno < 8)
-				{
-					digs[dno++] = *it++;
-				}
-				if (dno > 0)
-				{
-					ch = std::strtol(digs, NULL, 16);
-				}
+				//Invalid sequence!
+				break;
 			}
+			}//end switch
 		}
 
 		unsigned char utf8[4];
diff --git a/Foundation/testsuite/src/UTF8StringTest.cpp b/Foundation/testsuite/src/UTF8StringTest.cpp
index 42a48fbcf..6799ff35d 100644
--- a/Foundation/testsuite/src/UTF8StringTest.cpp
+++ b/Foundation/testsuite/src/UTF8StringTest.cpp
@@ -96,9 +96,11 @@ void UTF8StringTest::testUnescape()
 {
 	std::string s1("A \\t, a \\u000B, and an \\u0007 walk into a |, and the barman says \\u0402");
 	std::string s2("A \\t, a \\v, and an \\a walk into a |, and the barman says \\u0402");
+	std::string s3("\\\\");
 
 	assertTrue (UTF8::unescape(s1) == "A \t, a \v, and an \a walk into a |, and the barman says \xD0\x82");
 	assertTrue (UTF8::unescape(s2) == "A \t, a \v, and an \a walk into a |, and the barman says \xD0\x82");
+	assertTrue (UTF8::unescape(s3) == "\\");
 }