Streams_Stream::metas(): fall back to Streams/icon sizes, not Streams/image

[zattak1]

Stream permalinks advertise an og:image / twitter:image that 404s, for every stream type that has no Q/images/<type> config of its own — which includes Streams/chat, so every conversation permalink is affected.

Cause

Streams_Stream::metas():

try {
    $sizes = Q_Image::getSizes($this->type, $maxStretch);
} catch (Exception $e) {
    $sizes = Q_Image::getSizes('Streams/image', $maxStretch);
}
$iconFile = end($sizes);

Q_Image::getSizes() opens with Q_Config::expect("Q","images",$type,'sizes'), which throws when the type has no images entry — so for Streams/chat the catch branch is not an edge case, it is the path every request takes.

The two size lists in Streams/config/plugin.json:

"Streams/icon":  { "sizes": ["40","50","80","1000"] }
"Streams/image": { "sizes": ["40","50","80","200x","x200","1000x"] }

end() gives 1000.jpg on the first and 1000x.jpg on the second. But the files are written by Streams::importIcon($publisherId, $streamName, $sources, $save = "Streams/icon", …) — the first list. So the writer and the reader name two different config keys, and the meta tag asks for a file that was never generated.

Observed on a live install: the advertised …/icon/<time>/1000x.jpg returns 404 while its sibling …/icon/<time>/1000.jpg returns 200 with the real image. 40, 50 and 80 resolve identically under either key, which is why every other use of the icon looks correct and only link previews break.

By contrast a type that does carry an images config (Calendars/event) takes the try branch and unfurls correctly — the symptom tracks the presence of a config entry, not the data.

Fix

Fall back to Streams/icon, the list importIcon() writes with, so reader and writer agree. One word, no behaviour change for any type that has its own images config.