FIX(positional-audio): Wrong character size used for wide strings

"wchar_t" is usually 4 bytes big. That's not the case on Windows, where it's 2 bytes instead.

We cannot rely on that type on Linux because the target process could be native or running through Wine.

Also, it's possible that a game uses the same size for "wchar_t" on both Linux and Windows.

This commit introduces two variants of utf16ToUtf8():

1. Accepts std::u16string, for Windows processes.
2. Accepts std::u32string, for Linux processes.

The old variant, which accepted std::wstring, is removed to prevent misuses.

2 files changed, 33 insertions, 16 deletions

diff --git a/plugins/mumble_plugin_utils.h b/plugins/mumble_plugin_utils.h
index 4c690b169..fb82cbca1 100644
--- a/plugins/mumble_plugin_utils.h
+++ b/plugins/mumble_plugin_utils.h
@@ -28,14 +28,36 @@ union SingleSplit4Bytes {
 	constexpr SingleSplit4Bytes(const uint32_t value) : single(value) {}
 };
 
-static inline std::string utf16ToUtf8(const std::wstring &wstr) {
-	std::wstring_convert< std::codecvt_utf8_utf16< wchar_t > > conv;
-	return conv.to_bytes(wstr);
+/// Converts from UTF-8 to UTF-16.
+static inline std::wstring utf8ToUtf16(const std::string &str) {
+	try {
+		std::wstring_convert< std::codecvt_utf8_utf16< wchar_t > > conv;
+		return conv.from_bytes(str);
+	} catch (std::range_error &) {
+		return {};
+	}
 }
 
-static inline std::wstring utf8ToUtf16(const std::string &str) {
-	std::wstring_convert< std::codecvt_utf8_utf16< wchar_t > > conv;
-	return conv.from_bytes(str);
+/// Converts from UTF-16 to UTF-8.
+/// Meant to be used when "wchar_t" is 2 bytes, usually with Windows processes.
+static inline std::string utf16ToUtf8(const std::u16string &str) {
+	try {
+		std::wstring_convert< std::codecvt_utf8_utf16< char16_t >, char16_t > conv;
+		return conv.to_bytes(str);
+	} catch (std::range_error &) {
+		return {};
+	}
+}
+
+/// Converts from UTF-16 to UTF-8.
+/// Meant to be used when "wchar_t" is 4 bytes, usually with Linux processes.
+static inline std::string utf16ToUtf8(const std::u32string &str) {
+	try {
+		std::wstring_convert< std::codecvt_utf8_utf16< char32_t >, char32_t > conv;
+		return conv.to_bytes(str);
+	} catch (std::range_error &) {
+		return {};
+	}
 }
 
 // escape lossily converts the given
diff --git a/plugins/ut99/ut99.cpp b/plugins/ut99/ut99.cpp
index 691a78d50..004becbf0 100644
--- a/plugins/ut99/ut99.cpp
+++ b/plugins/ut99/ut99.cpp
@@ -143,20 +143,15 @@ static int fetch(float *avatar_pos, float *avatar_front, float *avatar_top, floa
 	procptr_t cptr1 = peekProcPtr(cptr0 + 0x73C);
 	procptr_t cptr2 = peekProcPtr(cptr1 + 0x244);
 
-
-	wchar_t wservername[60];
-
-	ok = peekProc((procptr_t) cptr2, wservername);
-	if (!ok)
+	std::u16string servername;
+	servername.resize(60);
+	if (!peekProc(cptr2, &servername[0], servername.size())) {
 		return false;
-
-	wservername[sizeof(wservername) / sizeof(wservername[0]) - 1] = '\0';
-
-	const std::string servername = utf16ToUtf8(wservername);
+	}
 
 	std::ostringstream contextss;
 	contextss << "{"
-			  << "\"servername\":\"" << servername << "\""
+			  << "\"servername\":\"" << utf16ToUtf8(servername) << "\""
 			  << "}";
 
 	context = contextss.str();