>> Today, if a user selects a file using <input type=file>, and then the file >> on the disk changes before the 'submit' is clicked, the form will submit >> the >> latest version of the file. >> This may be a surprisingly popular use case, when user submits a file via >> form and wants to do 'last moment' changes in the file, after partial >> pre-populating the form. It works 'intuitively' today. > > It is possible that two reads at different time intervals yield different > results, if the underlying file has undergone changes between those time > intervals. This holds true for read methods that take a Blob or a File > argument. > The case of modifications *during* a read may be operating system dependent.
For the record, I'd like to make the read "atomic", such that you can never get half a file before a change, and half after. But it likely depends on what OSs can enforce here. / Jonas