Horizontal scrollbar hides cell's last line on Firefox

[astrojuanlu]

In Firefox under Linux, when the cell contents are too wide the horizontal scrollbar hides the last line:

[takluyver]

One of @jdfreder's favourite bugs. Which version of IPython are you using?

[astrojuanlu]

I'm using 2.0.0beta1 on Python 3.

[ivanov]

IIRC I've seen this happen when zoomed in more than 100% before. Are you able to get this with just a really long line every time? Also, what is your monospace font set to?

[astrojuanlu]

I have tried again with IPython 1.2 and I am unable to reproduce this (the global horizontal scrollbar appears at the bottom of the browser), whereas every single time I put a long line the per-cell scrollbar hides the last one.

In both Firefox and Chromium the rendered font is DejaVu Sans Mono, but the failure appears only in Firefox.

[jdfreder]

I wrote this JS fiddle that reproduces the behavior (see the red box):
http://jsfiddle.net/tZVsS/211/

This is behavior is caused by this line:
https://github.com/ipython/ipython/blob/master/IPython/html/static/notebook/less/codemirror.less#L29

Which fixes this bug:
#3549

Which I still can't reproduce in Firefox 25+. If I was able to reproduce #3549, I would write a fiddle and open an issue with CodeMirror. Pinging @juhasch and @minrk since they were able to reproduce #3549 .

[juhasch]

So this is what happens in a notebook codecell with overflow-x: auto.
Nothing selected:

One line or more selected:

The top: value changes. This is the same in your JS fiddle, although the codemirror div doesn't change size like it does in a codecell.

[juhasch]

I need to add: It is exactly the same with overflow-x: hidden, i.e. I see no difference at all in the HTML, just in the browser display...

[jdfreder]

Hmmm. I do see that the top value changes depending on where the cursor is in the document (line selected or not). I'm guessing that that div has something to do with the cursor's current location.

Looking at the code that the element inspector shows, it's interesting that that is the only changing variable (I'm looking at it too).

[pybokeh]

I just want to report I am having this same problem as well with IPython version 2.0, Firefox version 28. When I switch to using Chrome, this is not a problem.