diag_edit do not save when nothing to sae (in directory browse view)
if you are browsing directory hiererchy, and enter a filename
and click save, it will write a zero byte file to that filename.
Note there was no data to write but the edit display was showing
the directory layout.
I suggest if a browse directory view is displayed then
the Save button should be disabled
or the save should indicate no data to save while in directory
browsing view and to not do anything.
(I noticed this while working on my book.
My list of bugs is at http://reedmedia.net/books/pfsense/bugs.html )