Re: [PATCH 1/2] xdiff: implement a zealous diff3, or "zdiff3"

Elijah Newren [off-list ref] writes:

On Tue, Jun 15, 2021 at 2:40 AM Felipe Contreras
[off-list ref] wrote:

quoted

Elijah Newren via GitGitGadget wrote:

quoted

From: Elijah Newren <redacted>

"zdiff3" is identical to ordinary diff3 except that it allows compaction
of common lines on the two sides of history at the beginning or end of
the conflict hunk.

That was not the main reason behind zdiff3.

The whole point of zdiff3 was to have something closer to the "merge"
style, even if not technically correct.

Your proposal is better than diff3 in that respect, but worse than Uwe's
zdiff3.

If you have this:

  l  b  r
  =  =  =
  A  A  A

  B     b
  C     C
  D     D
  E     E
  F     F
  I     i

merge will output this:

  A

  <<<<<<< l
  B
  =======
  b
  >>>>>>> r
  C
  D
  E
  F
  <<<<<<< l
  I
  =======
  i
  >>>>>>> r

This is simple, and useful.

diff3 will output this:

  A
  <<<<<<< l

  B
  C
  D
  E
  F
  I
  ||||||| b
  =======

  b
  C
  D
  E
  F
  i
  >>>>>>> r

Not very friendly.

For me it's friendly enough. One key-press in Emacs and I get:

--- upper/xx.txt
+++ lower/xx.txt

@@ -1,7 +1,7 @@
 
-B
+b
 C
 D
 E
 F
-I
+i

In a separate window, that is roughly what you've get in the "merge"
output in the first place, but even more compact.

My point is that once Git provides enough context, a good interactive
tool will do the rest just fine, beneficial to the end-user.

-- Sergey Organov