rerere fails to record resolution if file doesn't exist in merge base

rerere fails to record resolution if file doesn't exist in merge base

[Uwe Kleine-König]

Hello,

Some time ago, I sent a test for that[1], but the patch doesn't apply
anymore.

Anyhow, the failure still exists, even though the original report was
sent when rerere was still a perl script ...

	zeisberg@cassiopeia:/tmp/rerere$ git init
	Initialized empty Git repository in .git/
	zeisberg@cassiopeia:/tmp/rerere$ mkdir .git/rerere
	zeisberg@cassiopeia:/tmp/rerere$ echo just something to commit > file
	zeisberg@cassiopeia:/tmp/rerere$ git add file
	zeisberg@cassiopeia:/tmp/rerere$ git commit -m 1
	Created initial commit 51384cb: 1
	 1 files changed, 1 insertions(+), 0 deletions(-)
	 create mode 100644 file
	zeisberg@cassiopeia:/tmp/rerere$ git branch b
	zeisberg@cassiopeia:/tmp/rerere$ echo lala > lolo
	zeisberg@cassiopeia:/tmp/rerere$ git add lolo
	zeisberg@cassiopeia:/tmp/rerere$ git commit -m 2
	Created commit 98b91cc: 2
	 1 files changed, 1 insertions(+), 0 deletions(-)
	 create mode 100644 lolo
	zeisberg@cassiopeia:/tmp/rerere$ git checkout b
	Switched to branch "b"
	zeisberg@cassiopeia:/tmp/rerere$ echo lali > lolo
	zeisberg@cassiopeia:/tmp/rerere$ git add lolo
	zeisberg@cassiopeia:/tmp/rerere$ git commit -m 2a
	Created commit bb900f3: 2a
	 1 files changed, 1 insertions(+), 0 deletions(-)
	 create mode 100644 lolo
	zeisberg@cassiopeia:/tmp/rerere$ git pull . master
	Auto-merged lolo
	CONFLICT (add/add): Merge conflict in lolo
	Automatic merge failed; fix conflicts and then commit the result.
	zeisberg@cassiopeia:/tmp/rerere$ perl -n -i -e "print if /^l/" lolo
	zeisberg@cassiopeia:/tmp/rerere$ cat lolo
	lali
	lala
	zeisberg@cassiopeia:/tmp/rerere$ git rerere
	zeisberg@cassiopeia:/tmp/rerere$ 

In my eyes the last command should have recorded the resolution for
lolo, shouldn't it?

Best regards
Uwe

[1] http://article.gmane.org/gmane.comp.version-control.git/19267

-- 
Uwe Kleine-König

http://www.google.com/search?q=1+stone%3D

Re: rerere fails to record resolution if file doesn't exist in merge base

[Junio C Hamano]

Uwe Kleine-König  <ukleinek@informatik.uni-freiburg.de> writes:

> Anyhow, the failure still exists, even though the original report was
> sent when rerere was still a perl script ...
>
> 	zeisberg@cassiopeia:/tmp/rerere$ git init
> 	Initialized empty Git repository in .git/
> 	zeisberg@cassiopeia:/tmp/rerere$ mkdir .git/rerere

This should be creating .git/rr-cache, but what you said in your
message is correct regardless.

> In my eyes the last command should have recorded the resolution for
> lolo, shouldn't it?

I think two-file merge (ancestor did not have it, and you and he
added the path differently) is rare enough that it was dropped
outside of the radar.  A fix would probably be a trivial change
to builtin-rerere.c::find_conflict(), I think.  While it would
still be sane to insist that we do not do rerere for symlinks,
and require to have stages #2 and #3, we should be able to drop
the requirement to have stage #1.  rerere does not use
information from there anyway.

Not even compile tested, but something like this should do.

 builtin-rerere.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/builtin-rerere.c b/builtin-rerere.c
index c25b3d5..6ffc43d 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -168,19 +168,16 @@ static int find_conflict(struct path_list *conflict)
 	int i;
 	if (read_cache() < 0)
 		return error("Could not read index");
-	for (i = 0; i + 2 < active_nr; i++) {
-		struct cache_entry *e1 = active_cache[i];
-		struct cache_entry *e2 = active_cache[i+1];
-		struct cache_entry *e3 = active_cache[i+2];
-		if (ce_stage(e1) == 1 &&
-		    ce_stage(e2) == 2 &&
+	for (i = 0; i+1 < active_nr; i++) {
+		struct cache_entry *e2 = active_cache[i];
+		struct cache_entry *e3 = active_cache[i+1];
+		if (ce_stage(e2) == 2 &&
 		    ce_stage(e3) == 3 &&
-		    ce_same_name(e1, e2) && ce_same_name(e1, e3) &&
-		    S_ISREG(ntohl(e1->ce_mode)) &&
+		    ce_same_name(e2, e3) &&
 		    S_ISREG(ntohl(e2->ce_mode)) &&
 		    S_ISREG(ntohl(e3->ce_mode))) {
-			path_list_insert((const char *)e1->name, conflict);
-			i += 2;
+			path_list_insert((const char *)e2->name, conflict);
+			i++; /* skip over both #2 and #3 */
 		}
 	}
 	return 0;

Re: rerere fails to record resolution if file doesn't exist in merge base

[Uwe Kleine-König]

Hello Junio,

Junio C Hamano wrote:
> Uwe Kleine-König  <ukleinek@informatik.uni-freiburg.de> writes:
> 
> > Anyhow, the failure still exists, even though the original report was
> > sent when rerere was still a perl script ...
> >
> > 	zeisberg@cassiopeia:/tmp/rerere$ git init
> > 	Initialized empty Git repository in .git/
> > 	zeisberg@cassiopeia:/tmp/rerere$ mkdir .git/rerere
> 
> This should be creating .git/rr-cache, but what you said in your
> message is correct regardless.
You're right.  copy-n-paste error.
 
> > In my eyes the last command should have recorded the resolution for
> > lolo, shouldn't it?
> 
> I think two-file merge (ancestor did not have it, and you and he
> added the path differently) is rare enough that it was dropped
> outside of the radar.  A fix would probably be a trivial change
> to builtin-rerere.c::find_conflict(), I think.  While it would
> still be sane to insist that we do not do rerere for symlinks,
> and require to have stages #2 and #3, we should be able to drop
> the requirement to have stage #1.  rerere does not use
> information from there anyway.
> 
> Not even compile tested, but something like this should do.
It compiles, but seems not to work.  I will try to make up a test.

Best regards
Uwe

-- 
Uwe Kleine-König

http://www.google.com/search?q=5+choose+3

Re: rerere fails to record resolution if file doesn't exist in merge base

[Johannes Schindelin]

Hi,

On Mon, 9 Jul 2007, Uwe Kleine-K?nig wrote:

> Junio C Hamano wrote:
>
> > Not even compile tested, but something like this should do.
> It compiles, but seems not to work.  I will try to make up a test.

I compiled it, and it works as expected.  For safety, git-rerere leaves 
the index unmerged, so that you can verify that you wanted this 
resolution.

Will resubmit with a test case.

Ciao,
Dscho

[PATCH] rerere: record resolution even if file is not in merge base

[Johannes Schindelin]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 3676 bytes --]


Two-file merges were rare enough that they were dropped outside of the 
radar.  This fix is a trivial change to builtin-rerere.c::find_conflict().  
It is still sane to insist that we do not do rerere for symlinks, and 
require to have stages #2 and #3, but we can drop the requirement to have 
stage #1. rerere does not use information from there anyway.

This fix is from Junio, together with two tests to verify that it works
as expected.

Noticed by Uwe Kleine-König.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---

	Heh, this time I steal your patch and take all the credit ;-)

 builtin-rerere.c  |   17 +++++++----------
 t/t4200-rerere.sh |   44 +++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 46 insertions(+), 15 deletions(-)

diff --git a/builtin-rerere.c b/builtin-rerere.c
index c25b3d5..6ffc43d 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -168,19 +168,16 @@ static int find_conflict(struct path_list *conflict)
 	int i;
 	if (read_cache() < 0)
 		return error("Could not read index");
-	for (i = 0; i + 2 < active_nr; i++) {
-		struct cache_entry *e1 = active_cache[i];
-		struct cache_entry *e2 = active_cache[i+1];
-		struct cache_entry *e3 = active_cache[i+2];
-		if (ce_stage(e1) == 1 &&
-		    ce_stage(e2) == 2 &&
+	for (i = 0; i+1 < active_nr; i++) {
+		struct cache_entry *e2 = active_cache[i];
+		struct cache_entry *e3 = active_cache[i+1];
+		if (ce_stage(e2) == 2 &&
 		    ce_stage(e3) == 3 &&
-		    ce_same_name(e1, e2) && ce_same_name(e1, e3) &&
-		    S_ISREG(ntohl(e1->ce_mode)) &&
+		    ce_same_name(e2, e3) &&
 		    S_ISREG(ntohl(e2->ce_mode)) &&
 		    S_ISREG(ntohl(e3->ce_mode))) {
-			path_list_insert((const char *)e1->name, conflict);
-			i += 2;
+			path_list_insert((const char *)e2->name, conflict);
+			i++; /* skip over both #2 and #3 */
 		}
 	}
 	return 0;
diff --git a/t/t4200-rerere.sh b/t/t4200-rerere.sh
index 6f55ba0..cfcdb69 100755
--- a/t/t4200-rerere.sh
+++ b/t/t4200-rerere.sh
@@ -116,11 +116,12 @@ test_expect_success 'commit succeeds' \
 
 test_expect_success 'recorded postimage' "test -f $rr/postimage"
 
-git checkout -b third master
-git show second^:a1 | sed 's/To die: t/To die! T/' > a1
-git commit -q -a -m third
-
-test_expect_failure 'another conflicting merge' 'git pull . first'
+test_expect_success 'another conflicting merge' '
+	git checkout -b third master &&
+	git show second^:a1 | sed "s/To die: t/To die! T/" > a1 &&
+	git commit -q -a -m third &&
+	! git pull . first
+'
 
 git show first:a1 | sed 's/To die: t/To die! T/' > expect
 test_expect_success 'rerere kicked in' "! grep ======= a1"
@@ -164,4 +165,37 @@ test_expect_success 'garbage collection (part2)' 'git rerere gc'
 test_expect_success 'old records rest in peace' \
 	"test ! -f $rr/preimage && test ! -f $rr2/preimage"
 
+test_expect_success 'file2 added differently in two branches' '
+	git reset --hard &&
+	git checkout -b fourth &&
+	echo Hallo > file2 &&
+	git add file2 &&
+	git commit -m version1 &&
+	git checkout third &&
+	echo Bello > file2 &&
+	git add file2 &&
+	git commit -m version2 &&
+	! git merge fourth &&
+	sha1=$(sed -e "s/	.*//" .git/rr-cache/MERGE_RR) &&
+	rr=.git/rr-cache/$sha1 &&
+	echo Cello > file2 &&
+	git add file2 &&
+	git commit -m resolution
+'
+
+test_expect_success 'resolution was recorded properly' '
+	git reset --hard HEAD~2 &&
+	git checkout -b fifth &&
+	echo Hallo > file3 &&
+	git add file3 &&
+	git commit -m version1 &&
+	git checkout third &&
+	echo Bello > file3 &&
+	git add file3 &&
+	git commit -m version2 &&
+	! git merge fifth &&
+	git diff-files -q &&
+	test Cello = "$(cat file3)"
+'
+
 test_done
-- 
1.5.3.rc0.2769.gd9be2

Re: [PATCH] rerere: record resolution even if file is not in merge base

[Uwe Kleine-König]

Hello Johannes, hello Junio,

Johannes Schindelin wrote:
> Two-file merges were rare enough that they were dropped outside of the 
> radar.  This fix is a trivial change to builtin-rerere.c::find_conflict().  
> It is still sane to insist that we do not do rerere for symlinks, and 
> require to have stages #2 and #3, but we can drop the requirement to have 
> stage #1. rerere does not use information from there anyway.
> 
> This fix is from Junio, together with two tests to verify that it works
> as expected.
> 
> Noticed by Uwe Kleine-König.
when I tested Junio's patch and wrote that it doesn't work, I was wrong.
I just recompiled git-rerere and called that instead of the installed
version.  The problem there was, that merge didn't called the updated.

So:

Acked-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>

-- 
Uwe Kleine-König

http://www.google.com/search?q=1+hertz+in+sec**-1