unicode fixes

Author: malytomas

sources/libcore/unicode/utf.cpp

@@ -76,7 +76,8 @@ namespace cage
 	{
 		const auto t = una::utf8to32u(view(inBuffer));
 		CAGE_ASSERT(outBuffer.size() >= t.size());
-		detail::memcpy(outBuffer.data(), t.data(), t.size() * sizeof(uint32));
+		if (t.size())
+			detail::memcpy(outBuffer.data(), t.data(), t.size() * sizeof(uint32));
 		outBuffer = PointerRange<uint32>(outBuffer.begin(), outBuffer.begin() + t.size());
 	}
 
@@ -100,7 +101,8 @@ namespace cage
 	{
 		const auto t = una::utf32to8u(view(inBuffer));
 		CAGE_ASSERT(outBuffer.size() >= t.size());
-		detail::memcpy(outBuffer.data(), t.data(), t.size() * sizeof(char));
+		if (t.size())
+			detail::memcpy(outBuffer.data(), t.data(), t.size() * sizeof(char));
 		outBuffer = PointerRange<char>(outBuffer.begin(), outBuffer.begin() + t.size());
 	}
 

sources/test-core/unicode.cpp

@@ -1,3 +1,5 @@
+#include <vector>
+
 #include "main.h"
 
 #include <cage-core/unicode.h>
@@ -13,6 +15,25 @@ namespace
 		CAGE_TEST(a == c);
 		CAGE_TEST(utf32Length(a) == b->size());
 		CAGE_TEST(utf8Length(b) == c.size());
+		CAGE_TEST(utfValid(""));
+		CAGE_TEST(utf8to32("").empty());
+
+		{
+			std::vector<uint32> vec;
+			vec.resize(utf32Length(a) + 5);
+			PointerRange<uint32> range = vec;
+			utf8to32(range, a);
+			CAGE_TEST(range.size() == utf32Length(a));
+			const String d = utf32to8string(range);
+			CAGE_TEST(a == d);
+		}
+
+		{
+			std::vector<uint32> vec;
+			PointerRange<uint32> range = vec;
+			utf8to32(range, "");
+			CAGE_TEST(range.empty());
+		}
 	}
 
 	void testValidation()