[FF] Bogus doubled line break nums

[Garry Yao]

Currently the padding block bogus br logic is not right, it's appending the br for every newly established block, which sometimes cause too much line breaks:

Reproducing Procedures

1. Open the replace by class example page with enterMode: P;
2. Click on 'New Page' button to clear all content;
3. Enter one line text and press enter key;
4. Now press backspace key to delete the new line;
   • Expected Result: One key strike will bring you back to the first line;
   • Actual Result: Three key strike is necessary to back to the first line;

[Garry Yao]

The solution here would be checking if the new block already has some line content before appending the bogus br.

[Garry Yao]

The patch is proposing the following changes:

1. Checking block line content before appending the bogus br.
2. My testing doesn't shows opera is needing bogus br, please correct me.

[Josh Nisly]

This is similar to #3405.

[Josh Nisly]

The previous patch contained some extraneous changes that were committed in r3461. I have attached a new patch without those changes.

[Josh Nisly]

This patch fixes #3405 for me. Review?

[Garry Yao]

Merge highjinx's patch with the latest fixing at #3469.

[Frederico Caldeira Knabben]

Talking with Garry, we've found out that a simpler solution can be found for it. I'm attaching a new patch for it.

[Frederico Caldeira Knabben]

It turned out that this patch breaks the SHIFT+ENTER behavior, or even the ENTER key when enterMode = 'br'.

[Garry Yao]

I'm attaching a new patch to address this issue, and take over this ticket.

[Frederico Caldeira Knabben]

The problem with \ufeff is that it makes the caret stopping, as it counts like a visible character for the browser.

[Garry Yao]

Fred has found a way to hack out since it's a special case where only happen here.

[Garry Yao]

Fixed with [3493].