Re: [PATCH 7/7] xdiff: make diff3 the default conflictStyle

Sergey Organov wrote:

Junio C Hamano [off-list ref] writes:

quoted

I notice that "git merge --help" tells what each part separated by
conflict markers mean in both output styles, but does not make a
specific recommendation as to which one to use in what situation,
and it might benefit a few additional sentences to help readers
based on what you said, i.e. the "RCS merge" style that hides the
original is succinct and easier to work with when you are familiar
with what both sides did, while a more verbose "diff3" style helps
when you are unfamiliar with what one side (or both sides) did.

I don't get it. Once you have diff3 output, and you want something
simpler, you just kill the inner section, right? RCS merge output style
is simply inferior.

The issue here is not a mere inner section, it's a nested inner section
due to a recursive merge.

Personally I've never encountered these in real life, but you can
trigger them with the following synthetic example, and the output with
diff3 is:

--- a/content
+++ b/content

@@@ -1,1 -1,1 +1,13 @@@
++<<<<<<< HEAD
 +D
++||||||| merged common ancestors
++<<<<<<<<< Temporary merge branch 1
++B
++||||||||| 2c9519d
++1
++=========
++A
++>>>>>>>>> Temporary merge branch 2
++=======
+ C
++>>>>>>> C

While with merge is:

--- a/content
+++ b/content

@@@ -1,1 -1,1 +1,5 @@@
++<<<<<<< HEAD
 +D
++=======
+ C
++>>>>>>> C

I don't see why diff3 triggers the output of this temporary merge, that
is a bug in my book.

I would expect the output to simply be:

--- a/content
+++ b/content

@@@ -1,1 -1,1 +1,13 @@@
++<<<<<<< HEAD
 +D
++||||||| 2c9519d
++1
++=======
+ C
++>>>>>>> C

Cheers.

  git init repo &&
  cd repo &&

  echo 1 > content &&
  git add content &&
  git commit -m 1 content &&

  git checkout -b A master &&
  echo A > content &&
  git commit -m A content &&

  git checkout -b B master &&
  echo B > content &&
  git commit -m B content &&

  git checkout -b C A &&
  git rev-parse B >.git/MERGE_HEAD &&
  echo C > content &&
  git commit -m C -a &&

  git checkout -b D A &&
  git rev-parse B >.git/MERGE_HEAD &&
  echo D > content &&
  git commit -m D -a &&

  git -c merge.conflictstyle=diff3 merge -m final C &&
  cat content

-- 
Felipe Contreras