Zero-width spaces cause unwanted wrapping / empty newlines before inline blocks

[k7d]

Do you want to request a feature or report a bug?

Bug

What's the current behavior?

Slate inserts span with zero-width spaces in front of inline blocks
starting at the begging of a line. If the inline block is longer than the line and doesn't have any whitespace in it, it causes a permanent newline before the block. Another sideeffect is that you cannot use key down to move down - the caret is just stuck there. This can be repeated with included links example. Just type some text without whitespace and add a link to it:

(see the empty line abobe "longlong..")

This is a common scenario when implementing automatic link wrapping (ie. if I paste a link I want it to get automatically converted to a clickable link).

For now my workaround is to just do this:

span[data-slate-zero-width='z'] {display: none;}

It fixes the issue and seem to not break anything (but I'm not 100% sure).

What's the expected behavior?

There should be no line breaks/empty lines before inline block in the above scenario.

[k7d]

Actually display: none on zero-width spans does cause issues. @ianstormtaylor what if we replace U+200B with U+FEFF (ZERO WIDTH NO-BREAK SPACE)?

It seems to both fix the linebreak issue and doesn't breaking existing behaviour (for example adding text before inline block at a beginning of a line).

[ianstormtaylor]

@k7d good call, that sounds like a good solution to me!

[k7d]

okay cool i'll pr