[randominion]

I can tell you how.

A shitty Belkin KVM in certain configurations can allow this to happen.

There's a bug which keeps generating chr(32) characters when you activate the keyboard shortcut (scroll lock twice), and try to switch to another machine.

It will keep pumping out those spaces on whatever fields was selected at the time, so if you take your time before you switch back, you are going to be in for a lot of fun.

Haven't read the link yet, but wanted to share this sooner than later.

[datenwolf]

On a related note: Is there any easy way to tell Vim when in insert mode not to accept extra spaces at the end of a line, except a single one?

I've got of course checks in place that warn about trailing spaces and my Git hooks outright refuse a commit with trailing spaces. But it would be nice to catch that at the insert level.

You know, it may be cat who's typing.

[duijf]

Not exactly at insert mode, but this may be helpful:

    autocmd BufWritePre * :%s/\s\+$//e

Before you save a file, it removes all trailing whitespace (ironically using the same regex as in the article -- hasn't given me trouble yet though)

[vitd]

Nice find! Another one I heard about was that Microsoft's Windows keyboards, when used on a Mac, will sometimes insert a Control-P into the middle of your typing if you press the Windows key. Most apps just ignore it, but apparently not all!