Fix path of file_get_contents

[solracsf]

Try to fix #28370 and fix #27441

Avoid pre-pends the $path to the user's own storage.

[ChristophWurst]

Does this also work with anything other than a local filesystem?

[kesselb]

Does it work? ;) The "faulty" path rewrite is already happening in getLocalPath.

Trigger this faulty part / path is a bit tricky 🙈

1. Don't have the exif module for php installed
2. Comment the following code / let exif_imagetype return false:

   server/lib/private/legacy/OC_Image.php

   Lines 1303 to 1305 in 0edfb24

   	if (($info = getimagesize($fileName)) !== false) {
   	return $info[2];
   	}

   We want to generate a preview for a file that seems to be an image but we are unable to detect the type of the image and fallback to a default logic (that triggers this error)
3. Previews are cached. To always trigger the preview generation comment:

   server/lib/private/Preview/Generator.php

   Line 221 in 2a054e6

   return $node;

4. Set a breakpoint here:

   server/lib/private/legacy/OC_Image.php

   Line 624 in 46525f8

   $this->resource = imagecreatefromstring(\OC\Files\Filesystem::file_get_contents(\OC\Files\Filesystem::getLocalPath($imagePath)));

5. Upload some image file
6. Move the image file to the trash
7. Go to trash
8. Happy debugging 🐛

Does this also work with anything other than a local filesystem?

I don't think it has too. All other methods / cases in the above switch-case are working with the local filesystem directly. No Nextcloud Api is used to access a image file.

$this->resource = imagecreatefromstring(file_get_contents($imagePath)); should work in a similar way to read the image content into a string (and not use any Nextcloud Api like the other cases).

[ChristophWurst]

👍 🐘

[solracsf]

Hey @ChristophWurst can this be backported? ;)

[kesselb]

/backport to stable22

[kesselb]

/backport to stable21

[kesselb]

/backport to stable20

[backportbot-nextcloud]

The backport to stable20 failed. Please do this backport manually.

[backportbot-nextcloud]

The backport to stable21 failed. Please do this backport manually.