[bug-diffutils] RFE: Implement reverse diff

[Sérgio Basto]

Hi, 
since a long time I which have a reverse diff , which in diff command is just 
swap operators 
diff a b --reverse <=> diff b a 
for example:
diff -u newfile oldfile , I want see diff oldfile newfile, if everything is all 
right. and just do 
cp newfile oldfile .

just swap command (diff -u with cp )
diff -u newfile oldfile 
cp      newfile oldfile

will be easier built mini scripts ....

like patch, -R for short of reverse will be great.

TIA
-- 
Sérgio M. B.