Re: [PATCH] git-am: Handle "git show" output correctly

On 09/13/2012 12:19 AM, Junio C Hamano wrote:

Dan Johnson [off-list ref] writes:

quoted

quoted

Not really.  If we start encouraging people to use "git show" output
as a kosher input to "am", we would have to support such use
forever, and we end up painting ourselves in a corner we cannot get
out of easily.

If git am emitted a warning when accepting "git show" output, it seems
like it would support Peter's use-case without encouraging bad
behavior?

Are you seriously suggesting me to sell to our users a new feature
saying "this does not work reliably, we would not recommend using
it, no, really, don't trust it." from the day the feature is
introduced, especially when we know it will not be "the feature does
not work well yet, but it will, we promise" but is "and it may become
worse in the future"?

I do not see much point in doing that.

Besides, what bad behaviour do we avoid from encouraging with such
an approach?  As Peter said, the problem is not on the part of the
user who ended up with an output from "git show", when he really
wants output from "git format-patch".  Giving the warning to the
user of "git am" is too late.

It might be enough to either enable format-patch output or print a
warning to stderr when stdout is not a tty. I believe that would at
least mitigate the problem, and it might educate the user as well.
We already modify output format when stdout is not a tty (removing
colors), so we're not giving guarantees about its format when it's
piped somewhere. I believe that would provide almost every scenario
with the expected outcome (including 'git show | grep'), but there
will be a handful of very surprised people as well.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
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