Add check for number of sizevariants without sizes.

app/Actions/Diagnostics/Errors.php

@@ -6,6 +6,7 @@
 use App\Actions\Diagnostics\Pipes\Checks\AppUrlMatchCheck;
 use App\Actions\Diagnostics\Pipes\Checks\BasicPermissionCheck;
 use App\Actions\Diagnostics\Pipes\Checks\ConfigSanityCheck;
+use App\Actions\Diagnostics\Pipes\Checks\CountSizeVariantsCheck;
 use App\Actions\Diagnostics\Pipes\Checks\DBIntegrityCheck;
 use App\Actions\Diagnostics\Pipes\Checks\DBSupportCheck;
 use App\Actions\Diagnostics\Pipes\Checks\ForeignKeyListInfo;
@@ -42,6 +43,7 @@ class Errors
 		ForeignKeyListInfo::class,
 		DBIntegrityCheck::class,
 		SmallMediumExistsCheck::class,
+		CountSizeVariantsCheck::class,
 	];
 
 	/**

app/Actions/Diagnostics/Pipes/Checks/CountSizeVariantsCheck.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace App\Actions\Diagnostics\Pipes\Checks;
+
+use App\Contracts\DiagnosticPipe;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+/**
+ * This checks the Database integrity.
+ * More precisely if there are any pictures without an original.
+ *
+ * Such cases will crash the front-end.
+ */
+class CountSizeVariantsCheck implements DiagnosticPipe
+{
+	/**
+	 * {@inheritDoc}
+	 */
+	public function handle(array &$data, \Closure $next): array
+	{
+		if (!Schema::hasTable('size_variants')) {
+			return $next($data);
+		}
+
+		$num = DB::table('size_variants')->where('size_variants.filesize', '=', 0)->count();
+		if ($num > 0) {
+			// @codeCoverageIgnoreStart
+			$data[] = sprintf('Info: Found %d small images without filesizes.', $num);
+			$data[] = sprintf('     You can use `php artisan lychee:variant_filesize %d` to compute them.', $num);
+			// @codeCoverageIgnoreEnd
+		}
+
+		return $next($data);
+	}
+}