Re: git-diff between /dev/null and blob

Jakub Narebski [off-list ref] writes:

Junio C Hamano wrote:

quoted

Jakub Narebski [off-list ref] writes:

quoted

Currently, due to artifact of git-diff argument parsing you can get diff 
of two arbitrary blobs given by their sha1 id, e.g.
  git diff ab8050ceb4e43522e858768cc2c02fcb91839370 fd05278808d458602587bb024a48726018d30926

Just FYI, it is pretty much by design not artifact to allow
something like this:

      git diff master:Makefile next:Makefile

Which we could get using

        git diff master next -- Makefile

Eh, that comment completely misses the point, because the
example did not show its true strength.  Arbitrary two blob sha1
lets you do something like this:

	git diff v0.99:merge-cache.c master:merge-index.c
	git diff v0.99:pull.h fetch.h

        echo extra >>Makefile && git diff :0:Makefile HEAD^^:Makefile

        H=`(cat Makefile; echo extra) | git hash-object -w --stdin`
	echo "100644 $H 2	foobar" | git update-index --add --index-info
	git diff :2:foobar :Makefile

git-diff doesn't understand :<stage>:<filename> and :<filename> for
accessing index version of blob (git-cat-file for example understands
it).

You probably got this impression from a botched experiment or
something, but this statement is wrong as demonstrated above.

Junio C Hamano wrote:

Jakub Narebski [off-list ref] writes: 

       git diff v0.99:pull.h fetch.h

        echo extra >>Makefile && git diff :0:Makefile HEAD^^:Makefile

        H=`(cat Makefile; echo extra) | git hash-object -w --stdin`
      echo "100644 $H 2       foobar" | git update-index --add --index-info
      git diff :2:foobar :Makefile

quoted

git-diff doesn't understand :<stage>:<filename> and :<filename> for
accessing index version of blob (git-cat-file for example understands
it).

You probably got this impression from a botched experiment or
something, but this statement is wrong as demonstrated above.

Right, sorry.

And you can write ./<filename> to distinguish it from revision name, so
proposed ::<filename> extension is not needed.

-- 
Jakub Narebski
Warsaw, Poland
ShadeHawk on #git