Warning fixes, add warning to Cave Story if skip buffer effects is on

Common/Data/Encoding/Utf8.cpp

@@ -531,17 +531,17 @@ size_t encode_utf8_modified(uint32_t code_point, unsigned char* output) {
 	return 0;
 }
 
-// A function to convert regular UTF-8 to Java Modified UTF-8
+// A function to convert regular UTF-8 to Java Modified UTF-8. Only used on Android.
 // Written by ChatGPT and corrected and modified.
 void ConvertUTF8ToJavaModifiedUTF8(std::string *output, std::string_view input) {
 	output->resize(input.size() * 6); // worst case: every character is encoded as 6 bytes
 	size_t out_idx = 0;
 	for (size_t i = 0; i < input.length(); ) {
 		unsigned char c = input[i];
-		if (c == 0x00) {
+		if (c == 0) {
 			// Encode null character as 0xC0 0x80. TODO: We probably don't need to support this?
-			output[out_idx++] = 0xC0;
-			output[out_idx++] = 0x80;
+			output[out_idx++] = (char)0xC0;
+			output[out_idx++] = (char)0x80;
 			i++;
 		} else if ((c & 0xF0) == 0xF0) { // 4-byte sequence (U+10000 to U+10FFFF)
 			// Decode the Unicode code point from the UTF-8 sequence
@@ -562,9 +562,11 @@ void ConvertUTF8ToJavaModifiedUTF8(std::string *output, std::string_view input)
 		} else {
 			// Copy the other UTF-8 sequences (1-3 bytes)
 			size_t utf8_len = 1;
-			if ((c & 0xE0) == 0xC0) utf8_len = 2; // 2-byte sequence
-			else if ((c & 0xF0) == 0xE0) utf8_len = 3; // 3-byte sequence
-
+			if ((c & 0xE0) == 0xC0) {
+				utf8_len = 2; // 2-byte sequence
+			} else if ((c & 0xF0) == 0xE0) {
+				utf8_len = 3; // 3-byte sequence
+			}
 			memcpy(output->data() + out_idx, input.data() + i, utf8_len);
 			out_idx += utf8_len;
 			i += utf8_len;