Misc sanity checks

Common/Data/Encoding/Utf8.cpp

@@ -322,6 +322,10 @@ void ConvertUTF8ToJavaModifiedUTF8(std::string *output, std::string_view input)
 			output[out_idx++] = (char)0x80;
 			i++;
 		} else if ((c & 0xF0) == 0xF0) { // 4-byte sequence (U+10000 to U+10FFFF)
+			if (i + 4 > input.length()) {
+				// Bad.
+				break;
+			}
 			// Decode the Unicode code point from the UTF-8 sequence
 			uint32_t code_point = ((input[i] & 0x07) << 18) |
 				((input[i + 1] & 0x3F) << 12) |
@@ -345,6 +349,9 @@ void ConvertUTF8ToJavaModifiedUTF8(std::string *output, std::string_view input)
 			} else if ((c & 0xF0) == 0xE0) {
 				utf8_len = 3; // 3-byte sequence
 			}
+			if (i + utf8_len > input.length()) {
+				break;
+			}
 			memcpy(output->data() + out_idx, input.data() + i, utf8_len);
 			out_idx += utf8_len;
 			i += utf8_len;

Common/Thread/Waitable.h

@@ -30,9 +30,9 @@ public:
 			return true;
 
 		uint32_t us = budget_s > 0 ? (uint32_t)(budget_s * 1000000.0) : 0;
-		if (us == 0)
+		if (us == 0) {
 			return false;
-
+		}
 		std::unique_lock<std::mutex> lock(mutex_);
 		return cond_.wait_for(lock, std::chrono::microseconds(us), [&] { return triggered_.load(); });
 	}

Common/UI/Screen.cpp

@@ -313,8 +313,10 @@ void ScreenManager::sendMessage(UIMessage message, const char *value) {
 
 	// NOTE: Changed this to send the message to all screens, instead of just the top one,
 	// to allow EmuScreen to receive messages from popup menus. Hope this didn't break anything..
-	for (auto &iter : stack_) {
-		iter.screen->sendMessage(message, value);
+	for (const auto &iter : stack_) {
+		if (iter.screen) {
+			iter.screen->sendMessage(message, value);
+		}
 	}
 }