Re: [PATCH v2 1/2] Introduce config variable "diff.primer"

On Fri, 6 Feb 2009, Jeff King wrote:

if somebody really wants to call a porcelain and _disable_ options, I don't 
think "--no-primer" is necessarily the right interface. Instead, the actual 
command line options given override what's in diff.primer, so you can 
selectively disable whatever you like.

Sir I appreciate the intention, as I interpret it, that it's always better to 
accomplish something without adding new vocabulary.  I'd much rather avoid 
adding new vocab if possible.  If I'm missing something, I apologize ahead of 
time, but let me describe the problem I see.  Let's take the context size 
setting as an example, i.e. -U<n> or --unified=<n>.  Default is 3.  Let's say 
someone defines diff.primer = -U6.  Now, without --no-primer, how does a program 
say "use the default value for context."  Aren't there options for which no 
inverse counterpart exists?  Is there command-line syntax to disable all 
whitespace ignore options, e.g. to disable -b?  If not then we need --no-primer.