Incorrect padding on hexadecimal formatting of integers

[coder543]

The behavior in #48978 does not seem correct.

Playground link

The number of digits in the output doesn't seem to match the requested amount of padding.

[coder543]

It appears to be caused by the leading 0x, as demonstrated by it working in what I consider the intuitively correct fashion on this playground.

Maybe this is expected behavior to some people, but it certainly isn't what I was expecting.

[cuviper]

You get the same thing as printing numbers directly with {:#08x}, which also does count the 0x.

[fpgaminer]

Yes, this is the previous behavior when printing numbers directly. It includes the prefix as part of the length of the formatted number. It's odd behavior, but not new (I hit the paper cut previously ... it really is weird behavior, but I don't think we can change it now).