checkout --conflict=diff3: add a label for ancestor

git checkout --conflict=diff3 can be used to present conflicts hunks
including text from the common ancestor:

	<<<<<<< ours
	ourside
	|||||||
	original
	=======
	theirside
	>>>>>>> theirs

The added information is helpful for resolving a merge by hand, and
merge tools can usually understand it without trouble because it looks
like output from ‘diff3 -m’.

diff3 includes a label for the merge base on the ||||||| line, and it
seems some tools (for example, Emacs 22’s smerge-mode) cannot parse
conflict hunks without such a label.  Humans could use help in
interpreting the output, too.  So change the marker for the start of the
text from the common ancestor to include the label “base”.

git rerere’s conflict identifiers are not affected: to parse conflict
hunks, rerere looks for whitespace after the ||||||| marker rather
than a newline, and to compute preimage ids, rerere has its own code
for creating conflict hunks.  No other code in git tries to parse
conflict hunks.

Requested-by: Stefan Monnier <monnier@iro.umontreal.ca>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index d67f809a9ca150e9ca523013725044f3ef7ef8db..d652b4c95f9d6059998c1837dd661bb8194e2c56 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -149,7 +149,7 @@ static int checkout_merged(int pos, struct checkout *state)
        read_mmblob(&ours, active_cache[pos+1]->sha1);
        read_mmblob(&theirs, active_cache[pos+2]->sha1);
 
-       status = ll_merge(&result_buf, path, &ancestor, NULL,
+       status = ll_merge(&result_buf, path, &ancestor, "base",
                          &ours, "ours", &theirs, "theirs", 0);
        free(ancestor.ptr);
        free(ours.ptr);

diff --git a/t/t7201-co.sh b/t/t7201-co.sh
index 01175f74d2df7b2d4732b63cd1b7df477917ea7e..f3f0c4cfdc9298188834444b0b3391fbc5e549a1 100755 (executable)
--- a/t/t7201-co.sh
+++ b/t/t7201-co.sh
@@ -538,7 +538,7 @@ test_expect_success 'checkout with --merge, in diff3 -m style' '
        (
                echo "<<<<<<< ours"
                echo ourside
-               echo "|||||||"
+               echo "||||||| base"
                echo original
                echo "======="
                echo theirside
@@ -582,7 +582,7 @@ test_expect_success 'checkout --conflict=diff3' '
        (
                echo "<<<<<<< ours"
                echo ourside
-               echo "|||||||"
+               echo "||||||| base"
                echo original
                echo "======="
                echo theirside