Odd formatting bug in display of assembly code

Question

I hit an odd, though not critical bug in the display of assembly language code on the question Disassembler for intel 8080. There's a block of assembly code where the format is:

opcode operand1 operand2   comment

for each line. The poster originally formatted it using a block quote, but noted that it didn't look right. I changed it to be formatted as code, but saw something odd.

When I first did it, I hadn't lined up the comments. So I went back and lined them all up. While editing, the live preview showed that the first 3 lines had one less space before the comment than was actually there. This was odd, but I thought I'd just add a space to those lines. In the live preview they now lined up. But when I pressed the button to save the edits, suddenly they had 1 extra space in the actual display of the assembly code and they no longer aligned.

So I edited it again and removed the extra space. Sure enough the code in the editor looked fine, but the preview showed 1 too few spaces on those lines. But when I saved it, they came back and everything aligned.

Answer 1

They are caused by tabs, and yes, tabs are "evil" on Stack Exchange. They break code formatting.

Here is shown on the real post, no problem!

This is shown in the editor, still looks good!

And this is shown in the preview... hmm?

Finally, this is shown on the revision's source... eh?

The fix is easy but cumbersome: don't use tabs, align (manually) with spaces instead.