Warning message when patch is applied?
warning: includes/database/database.inc has type 100755, expected 100644


You can trust that the file has been applied successfully, but not that the file was in the expected state to begin with.

755 and 644 refering to numeric notation of unix-system file permissions.

What the warning says is that the patch lists the file as being not executable, but it found the file to be executable.
This had no effect on applying the contents of the patch to the file though.