Re: Making git as easy as CVS, for handling merge conflicts

Re: Making git as easy as CVS, for handling merge conflicts

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

Talking about my problems using git via Emacs and VC.  When I tried
this, a few years ago, something gave me three side-by-side windows
and I had no idea what to do with them, so I had to bail out.

  > Maybe, it was ediff-mode?

What does Ediff mode do?  Does it make three windows
side by side?

I looked at the doc strings of ediff-mode and ediff.  They give a few
secondary details but they don't even start to answer the questions,
"What is this good for?  What does it do?"  So I can't tell whether it
would make three windows.

Regardless of my git issues, those doc strings ought to be improved.
Would someone like to do it?

-- 
Dr Richard Stallman
Founder, Free Software Foundation (https://gnu.org, https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

Re: Making git as easy as CVS, for handling merge conflicts

[Óscar Fuentes]

Richard Stallman <rms@gnu.org> writes:

> I looked at the doc strings of ediff-mode and ediff.  They give a few
> secondary details but they don't even start to answer the questions,
> "What is this good for?  What does it do?"  So I can't tell whether it
> would make three windows.

The Ediff manual (listed on C-h i) gives a nice explanation of what
Ediff does on its Introduction node.

> Regardless of my git issues, those doc strings ought to be improved.
> Would someone like to do it?

Ediff has multiple entry points and explaining what Ediff does and its
basic concepts on each of those commands would be quite redundant, IMHO.

Re: Making git as easy as CVS, for handling merge conflicts

[Dmitry Alexandrov]

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Richard Stallman <rms@gnu.org> wrote:
>   > Maybe, it was ediff-mode?
>
> What does Ediff mode do?  Does it make three windows side by side?

When Emacs is running on TTY: yes, it does.  (While on graphical display — two windows side by side and one more in a new frame.)

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Re: Making git as easy as CVS, for handling merge conflicts

[martin rudalics]

 >> What does Ediff mode do?  Does it make three windows side by side?
 >
 > When Emacs is running on TTY: yes, it does.  (While on graphical display — two windows side by side and one more in a new frame.)

I've never seen an uncustomized 'ediff' make three side by side
windows.  Can you show us a backtrace of that happening?

Thanks, martin

Re: Making git as easy as CVS, for handling merge conflicts

[João Távora]

On Mon, Nov 11, 2019 at 3:04 AM Richard Stallman <rms@gnu.org> wrote:
>
> [[[ To any NSA and FBI agents reading my email: please consider    ]]]
> [[[ whether defending the US Constitution against all enemies,     ]]]
> [[[ foreign or domestic, requires you to follow Snowden's example. ]]]
>
> Talking about my problems using git via Emacs and VC.  When I tried
> this, a few years ago, something gave me three side-by-side windows
> and I had no idea what to do with them, so I had to bail out.
>
>   > Maybe, it was ediff-mode?
>
> What does Ediff mode do?  Does it make three windows
> side by side?

Ediff is an interactive Emacs interface to the classic diff algorithm,
where instead of seeing +'s and -'s, you see the two versions
that differ, one in each window.  You can copy hunks from one
version to the other interactive.

I think that ediff3, or ediff-files3, is an Emacs interface to the diff3
algorithm, which I know does the same for three versions, but,
perhaps much like you, it confuses me a lot.  Some people do
prefer to handle merge conflicts with it.

I handle Git merge conflicts using smerge-mode.  In that mode,
no new windows are created, but you see annotated and
highlighted portions for each conflicting part in the file. For each
little conflict region, you can click to decide which of the two
versions to keep or manually merge the two into one.

smerge-mode is automatically activated when you C-x C-f a
file with freshly produced merge conflicts.

João

Re: Making git as easy as CVS, for handling merge conflicts

[Eli Zaretskii]

On November 11, 2019 9:45:44 AM GMT, "João Távora" <joaotavora@gmail.com> wrote:
> On Mon, Nov 11, 2019 at 3:04 AM Richard Stallman <rms@gnu.org> wrote:
> >
> > [[[ To any NSA and FBI agents reading my email: please consider   
> ]]]
> > [[[ whether defending the US Constitution against all enemies,    
> ]]]
> > [[[ foreign or domestic, requires you to follow Snowden's example.
> ]]]
> >
> > Talking about my problems using git via Emacs and VC.  When I tried
> > this, a few years ago, something gave me three side-by-side windows
> > and I had no idea what to do with them, so I had to bail out.
> >
> >   > Maybe, it was ediff-mode?
> >
> > What does Ediff mode do?  Does it make three windows
> > side by side?
> 
> Ediff is an interactive Emacs interface to the classic diff algorithm,
> where instead of seeing +'s and -'s, you see the two versions
> that differ, one in each window.  You can copy hunks from one
> version to the other interactive.
> 
> I think that ediff3, or ediff-files3, is an Emacs interface to the
> diff3
> algorithm, which I know does the same for three versions, but,
> perhaps much like you, it confuses me a lot.  Some people do
> prefer to handle merge conflicts with it.
> 
> I handle Git merge conflicts using smerge-mode.  In that mode,
> no new windows are created, but you see annotated and
> highlighted portions for each conflicting part in the file. For each
> little conflict region, you can click to decide which of the two
> versions to keep or manually merge the two into one.
> 
> smerge-mode is automatically activated when you C-x C-f a
> file with freshly produced merge conflicts.
> 
> João

The context of this will be better understood if you first read the related duscussion on gnu-system-discuss, where it started.  RMS described there something that happened to him dyring resolution of Git conflicts.

Re: Making git as easy as CVS, for handling merge conflicts

[João Távora]

On Mon, Nov 11, 2019 at 10:36 AM Eli Zaretskii <eliz@gnu.org> wrote:
>
> On November 11, 2019 9:45:44 AM GMT, "João Távora" <joaotavora@gmail.com> wrote:
> > On Mon, Nov 11, 2019 at 3:04 AM Richard Stallman <rms@gnu.org> wrote:
> > >
> > > [[[ To any NSA and FBI agents reading my email: please consider
> > ]]]
> > > [[[ whether defending the US Constitution against all enemies,
> > ]]]
> > > [[[ foreign or domestic, requires you to follow Snowden's example.
> > ]]]
> > >
> > > Talking about my problems using git via Emacs and VC.  When I tried
> > > this, a few years ago, something gave me three side-by-side windows
> > > and I had no idea what to do with them, so I had to bail out.
> > >
> > >   > Maybe, it was ediff-mode?
> > >
> > > What does Ediff mode do?  Does it make three windows
> > > side by side?
> >
> > Ediff is an interactive Emacs interface to the classic diff algorithm,
> > where instead of seeing +'s and -'s, you see the two versions
> > that differ, one in each window.  You can copy hunks from one
> > version to the other interactive.
> >
> > I think that ediff3, or ediff-files3, is an Emacs interface to the
> > diff3
> > algorithm, which I know does the same for three versions, but,
> > perhaps much like you, it confuses me a lot.  Some people do
> > prefer to handle merge conflicts with it.
> >
> > I handle Git merge conflicts using smerge-mode.  In that mode,
> > no new windows are created, but you see annotated and
> > highlighted portions for each conflicting part in the file. For each
> > little conflict region, you can click to decide which of the two
> > versions to keep or manually merge the two into one.
> >
> > smerge-mode is automatically activated when you C-x C-f a
> > file with freshly produced merge conflicts.
> >
> > João
>
> The context of this will be better understood if you first read the
> related duscussion on gnu-system-discuss, where it started.
> RMS described there something that happened to him dyring
> resolution of Git conflicts.

Oops. I don't subscribe to that group.  I just tried answering
Richard's question "What does ediff mode do". Sorry for
the extra noise, then.

João

Re: Making git as easy as CVS, for handling merge conflicts

[Eli Zaretskii]

On November 11, 2019 10:49:02 AM GMT, "João Távora" <joaotavora@gmail.com> wrote:
> On Mon, Nov 11, 2019 at 10:36 AM Eli Zaretskii <eliz@gnu.org> wrote:
> >
> > On November 11, 2019 9:45:44 AM GMT, "João Távora"
> <joaotavora@gmail.com> wrote:
> > > On Mon, Nov 11, 2019 at 3:04 AM Richard Stallman <rms@gnu.org>
> wrote:
> > > >
> > > > [[[ To any NSA and FBI agents reading my email: please consider
> > > ]]]
> > > > [[[ whether defending the US Constitution against all enemies,
> > > ]]]
> > > > [[[ foreign or domestic, requires you to follow Snowden's
> example.
> > > ]]]
> > > >
> > > > Talking about my problems using git via Emacs and VC.  When I
> tried
> > > > this, a few years ago, something gave me three side-by-side
> windows
> > > > and I had no idea what to do with them, so I had to bail out.
> > > >
> > > >   > Maybe, it was ediff-mode?
> > > >
> > > > What does Ediff mode do?  Does it make three windows
> > > > side by side?
> > >
> > > Ediff is an interactive Emacs interface to the classic diff
> algorithm,
> > > where instead of seeing +'s and -'s, you see the two versions
> > > that differ, one in each window.  You can copy hunks from one
> > > version to the other interactive.
> > >
> > > I think that ediff3, or ediff-files3, is an Emacs interface to the
> > > diff3
> > > algorithm, which I know does the same for three versions, but,
> > > perhaps much like you, it confuses me a lot.  Some people do
> > > prefer to handle merge conflicts with it.
> > >
> > > I handle Git merge conflicts using smerge-mode.  In that mode,
> > > no new windows are created, but you see annotated and
> > > highlighted portions for each conflicting part in the file. For
> each
> > > little conflict region, you can click to decide which of the two
> > > versions to keep or manually merge the two into one.
> > >
> > > smerge-mode is automatically activated when you C-x C-f a
> > > file with freshly produced merge conflicts.
> > >
> > > João
> >
> > The context of this will be better understood if you first read the
> > related duscussion on gnu-system-discuss, where it started.
> > RMS described there something that happened to him dyring
> > resolution of Git conflicts.
> 
> Oops. I don't subscribe to that group.  I just tried answering
> Richard's question "What does ediff mode do". Sorry for
> the extra noise, then.
> 
> João

You can read the archives of gnu-system-discuss without subscribing.

I didn't mean to imply your response was a "noise" in any sense, I just said that reading that discussion will better explain why these questions are being asked.

Re: Making git as easy as CVS, for handling merge conflicts

[Dmitry Alexandrov]

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* ediff-setup-windows-plain-merge(#<buffer init.el> #<buffer init.el~> #<buffer *ediff-merge*> #<buffer *Ediff Control Panel*>)
  ediff-setup-windows-plain(#<buffer init.el> #<buffer init.el~> #<buffer *ediff-merge*> #<buffer *Ediff Control Panel*>)
  ediff-setup-windows(#<buffer init.el> #<buffer init.el~> #<buffer *ediff-merge*> #<buffer *Ediff Control Panel*>)
  ediff-setup(#<buffer init.el> "/home/dag/.emacs.d/init.el" #<buffer init.el~> "/home/dag/.emacs.d/init.el~" nil nil (ediff-merge-on-startup) ((ediff-job-name . ediff-merge-files)) nil)
  ediff-files-internal("/home/dag/.emacs.d/init.el" "/home/dag/.emacs.d/init.el~" nil (ediff-merge-on-startup) ediff-merge-files nil)
  ediff-merge("/home/dag/.emacs.d/init.el" "/home/dag/.emacs.d/init.el~")
  funcall-interactively(ediff-merge "/home/dag/.emacs.d/init.el" "/home/dag/.emacs.d/init.el~")

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Re: Making git as easy as CVS, for handling merge conflicts

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  > I think that ediff3, or ediff-files3, is an Emacs interface to the diff3
  > algorithm, which I know does the same for three versions, but,
  > perhaps much like you, it confuses me a lot.  Some people do
  > prefer to handle merge conflicts with it.

If so, why did a VC command invoke this automatically
without my requesting it?

-- 
Dr Richard Stallman
Founder, Free Software Foundation (https://gnu.org, https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

Re: Making git as easy as CVS, for handling merge conflicts

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  > > What does Ediff mode do?  Does it make three windows side by side?

  > When Emacs is running on TTY: yes, it does.  (While on graphical display — two windows side by side and one more in a new frame.)

So, how and where does vc invoke this, and is there a way to turn that off?

-- 
Dr Richard Stallman
Founder, Free Software Foundation (https://gnu.org, https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

Re: Making git as easy as CVS, for handling merge conflicts

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

  > > I looked at the doc strings of ediff-mode and ediff.  They give a few
  > > secondary details but they don't even start to answer the questions,
  > > "What is this good for?  What does it do?"  So I can't tell whether it
  > > would make three windows.

  > > Regardless of my git issues, those doc strings ought to be improved.
  > > Would someone like to do it?

  > Ediff has multiple entry points and explaining what Ediff does and its
  > basic concepts on each of those commands would be quite redundant, IMHO.

With a little imagination, it is surely possible to solve the problem
without much repetition.  Would someone like to try?

-- 
Dr Richard Stallman
Founder, Free Software Foundation (https://gnu.org, https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)

Re: Making git as easy as CVS, for handling merge conflicts

[Eli Zaretskii]

On November 12, 2019 3:15:49 AM GMT, Richard Stallman <rms@gnu.org> wrote:
> [[[ To any NSA and FBI agents reading my email: please consider    ]]]
> [[[ whether defending the US Constitution against all enemies,     ]]]
> [[[ foreign or domestic, requires you to follow Snowden's example. ]]]
> 
> > I think that ediff3, or ediff-files3, is an Emacs interface to the
> diff3
>   > algorithm, which I know does the same for three versions, but,
>   > perhaps much like you, it confuses me a lot.  Some people do
>   > prefer to handle merge conflicts with it.
> 
> If so, why did a VC command invoke this automatically
> without my requesting it?

It doesn't do that by itself.  One has to invoke a command to cause that.  Maybe you pressed the corresponding key sequence by accident (assuming it was Ediff that popped up those windows, which at this point is just a hypothesis)?

Re: Making git as easy as CVS, for handling merge conflicts

[Eli Zaretskii]

On November 12, 2019 3:18:10 AM GMT, Richard Stallman <rms@gnu.org> wrote:
> [[[ To any NSA and FBI agents reading my email: please consider    ]]]
> [[[ whether defending the US Constitution against all enemies,     ]]]
> [[[ foreign or domestic, requires you to follow Snowden's example. ]]]
> 
> > > I looked at the doc strings of ediff-mode and ediff.  They give a
> few
> > > secondary details but they don't even start to answer the
> questions,
> > > "What is this good for?  What does it do?"  So I can't tell
> whether it
>   > > would make three windows.
> 
> > > Regardless of my git issues, those doc strings ought to be
> improved.
>   > > Would someone like to do it?
> 
> > Ediff has multiple entry points and explaining what Ediff does and
> its
> > basic concepts on each of those commands would be quite redundant,
> IMHO.
> 
> With a little imagination, it is surely possible to solve the problem
> without much repetition.  Would someone like to try?

Ediff has its own Info manual.  Isn't that enough to document the feature?

Re: Making git as easy as CVS, for handling merge conflicts

[martin rudalics]

 > * ediff-setup-windows-plain-merge(#<buffer init.el> #<buffer init.el~> #<buffer *ediff-merge*> #<buffer *Ediff Control Panel*>)

But 'ediff-setup-windows-plain-merge' here shows only buf-A and buf-B
side by side.  It shows buf-C below these two and control-buffer at
the bottom of the frame.  I get the same setup on a GUI frame when I
set 'ediff-window-setup-function' to 'ediff-setup-windows-plain'.

Looking at the code I cannot see any indication that three side-by-side
windows could be created.  Can you resolve this mystery by walking
through 'ediff-setup-windows-plain-merge' and looking at the splits it
does for you?

Thanks, martin

Re: Making git as easy as CVS, for handling merge conflicts

[Dmitry Alexandrov]

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martin rudalics <rudalics@gmx.at> wrote:
>> * ediff-setup-windows-plain-merge(#<buffer init.el> #<buffer init.el~> #<buffer *ediff-merge*> #<buffer *Ediff Control Panel*>)
>
> But 'ediff-setup-windows-plain-merge' here shows only buf-A and buf-B side by side.  It shows buf-C below these two and control-buffer at the bottom of the frame.

Ah, yes.  When I said ‘side by side’, I had not meant ‘split vertically’, just ‘next to each other’, in this case: in the same frame.  Sorry for confusion.

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Re: Making git as easy as CVS, for handling merge conflicts

[martin rudalics]

 > Ah, yes.  When I said ‘side by side’, I had not meant ‘split
 > vertically’, just ‘next to each other’, in this case: in the same
 > frame.  Sorry for confusion.

And thanks for resolving it.

martin