fix(apps-store): Fix exception on generating preview url for installed app screenshot

[claucambra]

Summary

Some installed apps meant for older server versions might unexpectedly offer up screenshot values in a non-string format (e.g. health). Avoid an exception by checking first if the first app screenshot is indeed a string and only then trying to create the $proxyPreviewUrl

Example error:

{"reqId":"HMJg7Rkp0hOomzjCuXPs","level":3,"time":"2024-10-27T11:40:53+00:00","remoteAddr":"192.168.21.3","user":"admin","app":"index","method":"GET","url":"/index.php/settings/apps/list","message":"OCA\\Settings\\Controller\\AppSettingsController::createProxyPreviewUrl(): Argument #1 ($url) must be of type string, array given, called in /var/www/html/apps/settings/lib/Controller/AppSettingsController.php on line 250 in file '/var/www/html/apps/settings/lib/Controller/AppSettingsController.php' line 236","userAgent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.0 Safari/605.1.15","version":"31.0.0.3","exception":{"Exception":"Exception","Message":"OCA\\Settings\\Controller\\AppSettingsController::createProxyPreviewUrl(): Argument #1 ($url) must be of type string, array given, called in /var/www/html/apps/settings/lib/Controller/AppSettingsController.php on line 250 in file '/var/www/html/apps/settings/lib/Controller/AppSettingsController.php' line 236","Code":0,"Trace":[{"file":"/var/www/html/lib/private/AppFramework/App.php","line":161,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->","args":[{"__class__":"OCA\\Settings\\Controller\\AppSettingsController"},"listApps"]},{"file":"/var/www/html/lib/private/Route/Router.php","line":306,"function":"main","class":"OC\\AppFramework\\App","type":"::","args":["OCA\\Settings\\Controller\\AppSettingsController","listApps",{"__class__":"OC\\AppFramework\\DependencyInjection\\DIContainer"},{"_route":"settings.appsettings.listapps"}]},{"file":"/var/www/html/lib/base.php","line":1010,"function":"match","class":"OC\\Route\\Router","type":"->","args":["/settings/apps/list"]},{"file":"/var/www/html/index.php","line":24,"function":"handleRequest","class":"OC","type":"::","args":[]}],"File":"/var/www/html/lib/private/AppFramework/Http/Dispatcher.php","Line":146,"Previous":{"Exception":"TypeError","Message":"OCA\\Settings\\Controller\\AppSettingsController::createProxyPreviewUrl(): Argument #1 ($url) must be of type string, array given, called in /var/www/html/apps/settings/lib/Controller/AppSettingsController.php on line 250","Code":0,"Trace":[{"file":"/var/www/html/apps/settings/lib/Controller/AppSettingsController.php","line":250,"function":"createProxyPreviewUrl","class":"OCA\\Settings\\Controller\\AppSettingsController","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/apps/settings/lib/Controller/AppSettingsController.php","line":295,"function":"fetchApps","class":"OCA\\Settings\\Controller\\AppSettingsController","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppFramework/Http/Dispatcher.php","line":208,"function":"listApps","class":"OCA\\Settings\\Controller\\AppSettingsController","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppFramework/Http/Dispatcher.php","line":114,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->","args":[{"__class__":"OCA\\Settings\\Controller\\AppSettingsController"},"listApps"]},{"file":"/var/www/html/lib/private/AppFramework/App.php","line":161,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->","args":[{"__class__":"OCA\\Settings\\Controller\\AppSettingsController"},"listApps"]},{"file":"/var/www/html/lib/private/Route/Router.php","line":306,"function":"main","class":"OC\\AppFramework\\App","type":"::","args":["OCA\\Settings\\Controller\\AppSettingsController","listApps",{"__class__":"OC\\AppFramework\\DependencyInjection\\DIContainer"},{"_route":"settings.appsettings.listapps"}]},{"file":"/var/www/html/lib/base.php","line":1010,"function":"match","class":"OC\\Route\\Router","type":"->","args":["/settings/apps/list"]},{"file":"/var/www/html/index.php","line":24,"function":"handleRequest","class":"OC","type":"::","args":[]}],"File":"/var/www/html/apps/settings/lib/Controller/AppSettingsController.php","Line":236},"message":"OCA\\Settings\\Controller\\AppSettingsController::createProxyPreviewUrl(): Argument #1 ($url) must be of type string, array given, called in /var/www/html/apps/settings/lib/Controller/AppSettingsController.php on line 250 in file '/var/www/html/apps/settings/lib/Controller/AppSettingsController.php' line 236","exception":{},"CustomMessage":"OCA\\Settings\\Controller\\AppSettingsController::createProxyPreviewUrl(): Argument #1 ($url) must be of type string, array given, called in /var/www/html/apps/settings/lib/Controller/AppSettingsController.php on line 250 in file '/var/www/html/apps/settings/lib/Controller/AppSettingsController.php' line 236"}}

TODO

This is my first server PR so apologies if I messed something up

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[nickvergessen]

I'll amend the actual fix...

[susnux]

TIL: Do not trust the appinfo XSD.

[welcome]

Thanks for your first pull request and welcome to the community! Feel free to keep them coming! If you are looking for issues to tackle then have a look at this selection: https://github.com/nextcloud/server/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22

[nickvergessen]

TIL: Do not trust the appinfo XSD.

Well the problem is a bit that PHP's XML engine makes things a string until they appear multiple times 🙈

[joshtrichards]

/backport to stable30