Selecting another language (for the image description) does not work, advance typing is not left bound (typing eng should select english, but it selects altenglish at the moment

This does work for me. I click the dropdown, and when the list is visible, I can start typing the name of the desired language; when it is selected, I can press Enter to choose it. What is your user interface language – perhaps the translation of language names is unfortunate?

there is no way to select the second / third / … value in the select box.

When the list is visible, up/down arrow keys work for me to select previous/next value, with Enter to confirm the selection. (If you're using the keyboard to navigate with the Tab key, you can open the dropdown by pressing Enter or Space.)

The only choice as for now is to scroll down the complete list and find the additional language (usability!)

So yeah, this is not so horrible for me; I don't think the experience is worse than a plain HTML dropdown, like the ones we had before. I noticed now that the list is ordered in a funny way, though, and I filed T121625 about it.

My defaultlanguage is German, and I usually add descriptions also in English.

So it occurs with English. I type 'eng' and 'altenglish' is selected (I cannot select the next match - how?). Using up/down arrows will select the next value, not the next value matching the characters already typed. So it can be quite a long way.

I'm now stuck to the following workaround: type 'Emi', which selects 'Emiliano-Romagnolo', a language I neither speak nor know, but which is just one line above 'English'. :-(

Would it be possible to left bind the typing ahead? Instead of matching any language name containing the typed characters? E will jump to Eastern Canadian, En will jump to English?
I do not think it's related to language translations.

Sorry, I had to work on other priorities for a while, but I looked into this today.

Would it be possible to left bind the typing ahead? Instead of matching any language name containing the typed characters? E will jump to Eastern Canadian, En will jump to English?

This is exactly what should be happening. The dropdown uses a prefix search. Here's a recording of me typing "e", "n", "g" into the dropdown when using German interface language:

So I don't know what was happening. Maybe you were running into T125740?

I found out, that I can use the cursor down in the search bar of firefox (alternatively use ⌘ G on Mac) to navigate through the six occurences. So this will help. (And I will not insist on improvement.)

But compared to the normal html dropdown, the behavior is different (and worse IMHO): in normal html dropdown box typing seems to be left bound ('e' will select the first option starting with letter 'e', and I can use cursor down to scroll to the next 'e*' entry), while with the sophisticated dropdown we now do have, entering 'e' will select the first option containing a letter 'e', which is any '*e*' and the wanted option can be far away, so scrolling with the cursor key isn't really an option (we do have > 250 languages!).

On the other hand the new behavior is of advantage, if you don't know the precise name of the language you want.

And there seems to be a relation with T125740. But not the root cause.

as a proposal to meet the needs of both:
advance typing will select the matching options and only the matching options, thus reducing the size of the dropdown menu with each character you type. After entering 'eng' only 6 options will be left (all containing 'eng', not necessarily left bound) and it will be easy to select using the cursor keys.
I know this from different software, which is also based on jquery.

In T121196#2006759, @Herzi.Pinki wrote:

But compared to the normal html dropdown, the behavior is different (and worse IMHO): in normal html dropdown box typing seems to be left bound ('e' will select the first option starting with letter 'e', and I can use cursor down to scroll to the next 'e*' entry), while with the sophisticated dropdown we now do have, entering 'e' will select the first option containing a letter 'e', which is any '*e*' and the wanted option can be far away, so scrolling with the cursor key isn't really an option (we do have > 250 languages!).

That is exactly what should be happening. That is what is implemented. There is no way I can see in which it could be matching anywhere but at the beginning.

Hmm, does the search bar at the bottom actually pop up when you just type "eng"? It's not supposed to (and it doesn't for me using Firefox on Windows 7).

Do you normally have the search bar pop up when typing without putting the cursor into any text field? That looks like a weird browser/extension feature. If so, then I think the fix for T126239 should prevent it from appearing here (and allow our matching to happen). Can you try if it's happening on http://commons.wikimedia.beta.wmflabs.org/wiki/Special:UploadWizard?

Hi, thanks for fixing that. It is ok for me now. Seems to be that the navigation in the dropdown menu is leftbound again.