sandrobt.wiki wrote:

Maybe writing "short" in the title was a mistake (but anyway this bug appears more often with short titles): SEGA, FIDO and GOOGLE also are not recognized as existing pages. However these are all redirects, so perhaps this is another known independent issue?

Redirects not showing in the list are due to case sensitivity issues, see bug 50898

Single character titles are never recognised, whether they are articles (e.g [[A]], [[Ä]]) or redirects, so I'm boldly refocusing this bug solely on this issue.

sandrobt.wiki wrote:

What about "AB" or "FRA"? Those are not redirects. Maybe "single character titles" is not accurate enough.

Created attachment 13081
Link dialog doesn't recognise that existence of single-character page names

Attached:

(In reply to comment #3)

What about "AB" or "FRA"? Those are not redirects. Maybe "single character
titles" is not accurate enough.

Hmm, although redirects do exist at Ab and Fra which is probably confusing the issue. I think all TLAs exist as redirects or articles in uppercase and titlecase form so I don't know how to test this.

(In reply to comment #4)

Created attachment 13081 [details]
Link dialog doesn't recognise that existence of single-character page names

This shows that it is the page name (excluding namespace) not the full page name (including namespace) that matters as [[User:A]] (which exists) is not recognised.

Attached:

sandrobt.wiki wrote:

Hmm, although redirects do exist at Ab and Fra which is probably confusing
the
issue. I think all TLAs exist as redirects or articles in uppercase and
titlecase form so I don't know how to test this.

Also User:AB and User:FRA erroneously appear as non-existing (and user:Ab and User:Fra don't exist).

(edit conflict)
Actually assuming that what happens in the user: namespace matches what happens in the article namespace then it is to do with the presence of a redirect. [[User:Rob]] exists but no pages (redirects or otherwise) exist for other capitalisations of those three letters. [[User:Rob]] does appear in the list of suggestions. Now whether that is this bug or bug 50898 I haven't got a clue, so I'll comment there as well.

(new text)
So it appears that it might be capitalisation related rather than redirect related - it works with sentence case Rob but not allcaps AB and FRA.

Hmm, not necessarily as simple as that as it recognises [[User:ABC]] and [[user:APL]]. It recognises both [[User:BBX]] and [[User:Bbx]] which are different pages and different users (the former Irish the latter a Finland-Swede).

It doesn't recognise [[User:Jim]] but that is a redirect to [[User:Jim (usurped)]].

It does recognise [[User:RVJ]], [[User:ZzZ]] and [[User:PQ3]].

I'm stumped!

sandrobt.wiki wrote:

Another surprising case is "Cara" on it.wiki. It exists and it is not a redirect but is not recognized as existent (neither writing "Cara" nor "cara"), and "CARA" doesn't exist at all.
So I guess this is not (only) related with redirects and it definitely appears also with pages with more than one character.

Indeed very, very odd. I've adjusted the bug summary to reflect the discovered behaviour. It is almost certainly unrelated to redirects though.

• Bug 53547 has been marked as a duplicate of this bug. ***

This is because VisualEditor relies on MediaWiki's search system to work out what pages exist, and the search engine ignores short strings as not worth bothering with.

We could theoretically fix this in VisualEditor with a hack, but fixing search would be a better solution.

• This bug has been marked as a duplicate of bug 51013 ***