Why does Drupal store the uploaded files for a content node even if the content is not created? In Drupal 7, I try to create a News, which is a custom content type, with an Image file. I upload the file (not by pressing Ajax button, but just selecting the file), and leave all the other fields (some mandatory) empty. I press Send, and I get the red errors. Even if I close the browser, the image will have been uploaded to the folder ( sites/default/files/news/images ). Even after deleting cache and running cron.php, the orphane image will be still there. Isn't it a bug of Drupal, which would have to delete those images with no associated content? The file is not reused in other content types.
I have discovered that the files are physically stored, and also in the database, there is an entry in the table file_managed with the field status with the following indication and value : 0

A field indicating the status of the file. Two status are defined in core:
temporary (0) and permanent (1).
Temporary files older than DRUPAL_MAXIMUM_TEMP_FILE_AGE will be removed during a cron run.


I have manually changed the timestamp of the uplodaded file, run the cron, and the file dissapears. Obviously there must be a confident time, because if not, files in contents still being update could have the risk of being deleted. My fault for not thinking of this last point.