Properly replace open graph favicon

[LukasReschke]

server/apps/files_sharing/lib/Controller/ShareController.php

Lines 375 to 380 in ad24b86

	if ($shareTmpl['previewSupported']) {
	$shareTmpl['previewImage'] = $this->urlGenerator->linkToRouteAbsolute( 'files_sharing.PublicPreview.getPreview',
	['x' => 200, 'y' => 200, 'file' => $shareTmpl['directory_path'], 't' => $shareTmpl['dirToken']]);
	} else {
	$shareTmpl['previewImage'] = $this->urlGenerator->getAbsoluteURL($this->urlGenerator->imagePath('core', 'favicon-fb.png'));
	}

is not replacing the OpenGraph favicon so when sharing to Twitter, Facebook or some other place parsing it the icon will still show the Nextcloud logo.

We should probably use \OCA\Theming\Controller\IconController::getTouchIcon here if available.

[JaredBoone]

@MorrisJobke I'd like favicon-fb.png to be overridden by the favicon specified in the Theming app. It's not currently the case (as of 15.0.2). Who should I talk to about that and how can I help? Thanks!

[MorrisJobke]

cc @juliushaertl

@JaredBoone Could you also open a separate ticket for this. It seems the old icon is used there as well for untamed instances.

[juliushaertl]

@JaredBoone Yes, please open a new ticket for this. If you want to look into fixing this, the relevant code part where the icons are replaced is here: https://github.com/nextcloud/server/blob/master/apps/theming/lib/ThemingDefaults.php#L337-L342