Equivalent of "bzr diff -rancestor:"

Equivalent of "bzr diff -rancestor:"

[Stefan Monnier]

I can't seem to figure out how to do the above.

Say, I'm on local branch "foo" which tracks a remote branch "foo", and
I'd like to see what are the changes on this branch foo compared to "master".

In Bazaar, I'd do something like "bzr diff -r ancestor:<master>"
but I can't find any equivalent in "man gitrevisions".

The best I can come up with is to arrange for "foo" to be uptodate with
respect to "master", and then I can just do "git diff <master>", but
sometimes it's inconvenient/impractical to be "uptodate".


        Stefan

Re: Equivalent of "bzr diff -rancestor:"

[Nicolas Richard]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> I can't seem to figure out how to do the above.
>
> Say, I'm on local branch "foo" which tracks a remote branch "foo", and
> I'd like to see what are the changes on this branch foo compared to
> "master".
>
> In Bazaar, I'd do something like "bzr diff -r ancestor:<master>"
> but I can't find any equivalent in "man gitrevisions".
>
> The best I can come up with is to arrange for "foo" to be uptodate with
> respect to "master", and then I can just do "git diff <master>", but
> sometimes it's inconvenient/impractical to be "uptodate".

Perhaps you want:
git diff origin/foo master

You need to "git fetch" first, so that origin/foo is uptodate.

-- 
Nicolas Richard

Re: Equivalent of "bzr diff -rancestor:"

[Andreas Schwab]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Say, I'm on local branch "foo" which tracks a remote branch "foo", and
> I'd like to see what are the changes on this branch foo compared to "master".
>
> In Bazaar, I'd do something like "bzr diff -r ancestor:<master>"
> but I can't find any equivalent in "man gitrevisions".

Do you mean "git diff $(git merge-base HEAD master)"?

Andreas.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."

Re: Equivalent of "bzr diff -rancestor:"

[Stefan Monnier]

>> In Bazaar, I'd do something like "bzr diff -r ancestor:<master>"

> Perhaps you want:
> git diff origin/foo master

This just shows the diff between the head of both branches.
Whereas I want the diff between the head of "foo" and the common ancestor
between "foo" and "master".


        Stefan

Re: Equivalent of "bzr diff -rancestor:"

[Stefan Monnier]

>> Say, I'm on local branch "foo" which tracks a remote branch "foo", and
>> I'd like to see what are the changes on this branch foo compared to "master".
>> In Bazaar, I'd do something like "bzr diff -r ancestor:<master>"
>> but I can't find any equivalent in "man gitrevisions".
> Do you mean "git diff $(git merge-base HEAD master)"?

Hmm... yes, exactly, thanks!
Now the next problem: `C-x v =' doesn't like

   $(git merge-base HEAD master)

:-(


        Stefan

Re: Equivalent of "bzr diff -rancestor:"

[Teemu Likonen]

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Stefan Monnier [2014-11-17 09:45:58 -05:00] wrote:

> Say, I'm on local branch "foo" which tracks a remote branch "foo", and
> I'd like to see what are the changes on this branch foo compared to
> "master".

Don't know Bazaar very well so here is my guess about what you may want.
A diff between master's and foo's common ancestor and the tip of foo:

    git diff master...foo           # Three dots.

In other words, it's is a diff between A and B in the graph below.


    o---o---A---o---o----o master
             \
              \--o---o---B foo


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Re: Equivalent of "bzr diff -rancestor:"

[Stefan Monnier]

> Don't know Bazaar very well so here is my guess about what you may want.
> A diff between master's and foo's common ancestor and the tip of foo:

>     git diff master...foo           # Three dots.

Ha!  That does it, without resorting to running another command to
compute the common ancestor.

This said, "C-u C-x v =" still doesn't like it, because it uses
diff-index rather than diff, and diff-index doesn't seem to like
"master...".


        Stefan

Re: Equivalent of "bzr diff -rancestor:"

[Nicolas Richard]

Stefan Monnier <monnier@IRO.UMontreal.CA> writes:

>>> In Bazaar, I'd do something like "bzr diff -r ancestor:<master>"
>
>> Perhaps you want:
>> git diff origin/foo master
>
> This just shows the diff between the head of both branches.
> Whereas I want the diff between the head of "foo" and the common ancestor
> between "foo" and "master".

Ah, sorry. That is "git diff ...foo"

Quoting "git help diff" :

> git diff [--options] <commit>...<commit> [--] [<path>...]
>            This form is to view the changes on the branch containing and
>            up to the second <commit>, starting at a common ancestor of
>            both <commit>. "git diff A...B" is equivalent to "git diff
>            $(git-merge-base A B) B". You can omit any one of <commit>,
>            which has the same effect as using HEAD instead.



-- 
Nicolas Richard