David Heffernan

It's just an artifact of the debugger visualiser. You are seeing some octal representations. The values are fine. As others have told you already. Your real problem is the misuse of strings to perform binary operations.

It's not possible to run most of the code you presented as it doesn't compile. As for my points regarding encryption and text/bytes, those points don't require any code to be run. Please feel free to ignore my advice if you feel I am wrong.

If you are working with AES encryption then the entire topic is moot because you should not be using text at all. Your entire code should operate on bytes.

https://stackoverflow.com/questions/56724326/find-longest-utf-8-sequence-without-breaking-multi-byte-sequences Self synchronisation is the keyword. Once you understand that then the code will emerge.

Everything is fine here. No bug in Delphi. However, your code that performs xor on character ordinal values and pushes the output back into strings is defective.

That code is completely different from the original post, which did not compile. The new code doesn't compile either. The code can't do anything useful because you will generate strings that are invalid with respect to their encoding. What are you actually trying to do here? It's hard to get enthused for an algorithm that is so clearly flawed.

What is this code meant to be doing? As presented here it won't compile: C := Byte(S xor T); You can't use xor with pointers. If you are hoping to perform bytewise xor on a UTF8 buffer and then interpret that as a string, that won't work. You can't guarantee that the output will be valid in any text encoding. You talk about operations on Char, but you aren't using Char. Char is a UTF-16 character element. You are (I think) attempting to operate on bytes. It's pointless to call SetLength to allocate a string S and then write S := because the first string you allocated is just thrown away. Each of your calls to SetLength is pointless and can be removed without changing the meaning of the program. Your for loop doesn't increment the pointers, and doesn't refer to the loop variable. That can't be right. You have a smiley face emoji in your code. Is that meant to be a variable named D? I guess you need to make sure that the code that you paste is correct. I recommend that you produce a complete program that you verify compiles, that produces the output you describe, and that you reproduce faithfully here.

Of course it is just an interface to the system task scheduler service.

API

Eventually when you discover all the flaws in your solution you'll come back to using the system scheduler.

Why don't you use the system scheduler?

It allows the system loader to take decisions at the time it starts up the process and before any code of the process executes. For instance, it allows the loader to make decisions about how to resolve dependencies (assemblies). Those decisions need to be made by the loader because implicit load time dependencies are resolved by the loader. There are many other things that are influenced by settings in the manifest. You can find out what they are by reading the documentation.

I can't see your rc file. Can you include it.

What is in the rc file?

The language documentation is pretty good. I'm sure you could read that and be up to speed.

Why? You mean the choice between nil and Default(T) as the result of Default(Nullable<T>)? In C# the default value is nil.

Just upload the image to some file sharing site. And show your code to process the EXIF.

Turn this into an opportunity!

What about work with a different language?

System.Default(), still not documented I think

Seems unlikely that your diagnosis is accurate. If you could provide an example file and your code I think it would be easy enough to find out what's up.

If lots of people tell you that they don't fully understand your question, I respectfully suggest that you clarify what you are asking. It's easy for us all to write things that we think are clear but find that others don't fully understand. My guess is that you want to stop your program putting anything onto the Windows clipboard. Exactly how to do that depends very heavily on what controls your program uses.

Then you'll have to debug this yourself.

If you want to solve a problem, the first step is to understand it fully. Guesswork is unlikely to be successful. If you want help from others, help them to be able to reproduce the issue.

That reproduction is still required