Vertical tabs summaries have stray spaces

Hmm, unrelated, but should all those tab headings say Show and Hide?

It does make the summary more readable... but on the other hand, doesn't that make the vertical tabs rather too tall and remove part of their original design intent to be compact?

Ha. Tracked it down! The problem is that field labels are made like this:

'!title !required'

So if there is no required on a field, it gets a stray space at the end.

I think the correct fix is to remove that space, rather than have the vertical tabs JS jump through hoops in every form that uses them to trim the values!

Dave Reid's suggestion in #2 really belongs in a feature request; and the inclusion of checkbox description is another bug for another day. The patch here fixes the original stated problem :)

Tagging for backport, removing need to UX review as that's for the improvement suggestion.

For the before screenshot, see the original post.
For the after screenshot, imagine that but without the spaces marked with big red circles ;)

Urgh. Patch no longer fixes the problem O_o

The problem is now happening somewhere in the JS -- I've got it as far as drupalGetSummary but there my JS skills run out :(

Ok the problem with the earlier patch is that the logic was flawed -- I was putting in the space at the front !required even when $required was empty.

That doesn't fully fix the problem though, and the culprit is this:

    case 'after':
      $output .= ' ' . $prefix . $element['#children'] . $suffix;
      $output .= ' ' . theme('form_element_label', $variables) . "\n";
      break;

I presume the final \n is there for readability of HTML source.
Now I'm not sure anyone actually bothers reading HTML source any more -- I certainly haven't since Firebug came along. But I'm not sure that's a call we should be making in this issue. Also, removing just one trailing newline in a switch() where the other cases have them makes the code look weird.

But here's that change as a patch for discussion. Another approach to follow.

Here's the other way of doing it: just have the JS trim() any text that goes into fieldset summary that has come from a title string.

Not as elegant, but no ideological changes involved :)

Yup, agreed -- that has the wider scope and the patch to cover it.

(Though I can't believe it's taken this long for other people to notice / be bugged by those spaces! ;)

Reopening this. It was marked as a duplicate of #1623574: Remove trailing space from form element labels and field labels (HTML nbsp), but that was committed back in 2014, and I am still seeing this problem on D8.