Re: Re: [PATCH v11 2/2] am: support --empty=<option> to handle empty patches

It is quite complicated to support 'git commit --allow-empty' extracting messages
from an empty patch, because 'git am' has to find somewhere to store the parsed state
for 'git commit' to read. How about directly supporting another interactive option
'--allow-empty' for 'git am' to keep recording?

Dears Hamano,

   Elijah Newren has given two better suggestions:

       1. Use 'ask' rather than 'die'
       2. When erroring out 'Patch is empty', print out a tutorial information
          to help users using 'git commit --allow-empty' to keep recording as 
          an empty commit.

   Should we continue to implement these features in current PR?

Aleen