* [PATCH 1/2] merge-base: fix duplicates and not best ancestors in output @ 2013-12-28 10:22 Василий Макаров 2013-12-30 19:01 ` Junio C Hamano 0 siblings, 1 reply; 4+ messages in thread From: Василий Макаров @ 2013-12-28 10:22 UTC (permalink / raw) To: git; +Cc: jrnieder Hi there! First of all: I'm new to mailing-lists, sorry if I'm doing it wrong. I've found a bug in git merge-base, causing it to show not best common ancestors and duplicates under some circumstances (example is given in attached test case). Problem cause is algorithm used in get_octopus_merge_bases(), it iteratively concatenates merge bases, and don't care if there are duplicates or decsendants/ancestors in result. What I suggest as a solution is to simply reduce bases list after get_octopus_merge_bases(). Here is the fix: --- builtin/merge-base.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/builtin/merge-base.c b/builtin/merge-base.c index e88eb93..d6ad330 100644 --- a/builtin/merge-base.c +++ b/builtin/merge-base.c @@ -44,19 +44,19 @@ static struct commit *get_commit_reference(const char *arg) return r; } -static int handle_octopus(int count, const char **args, int reduce, int show_all) +static int handle_octopus(int count, const char **args, int reduce_only, int show_all) { struct commit_list *revs = NULL; struct commit_list *result; int i; - if (reduce) + if (reduce_only) show_all = 1; for (i = count - 1; i >= 0; i--) commit_list_insert(get_commit_reference(args[i]), &revs); - result = reduce ? reduce_heads(revs) : get_octopus_merge_bases(revs); + result = reduce_heads(reduce_only ? revs : get_octopus_merge_bases(revs)); if (!result) return 1; -- 1.8.3.1 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] merge-base: fix duplicates and not best ancestors in output 2013-12-28 10:22 [PATCH 1/2] merge-base: fix duplicates and not best ancestors in output Василий Макаров @ 2013-12-30 19:01 ` Junio C Hamano 2013-12-30 20:06 ` Junio C Hamano 0 siblings, 1 reply; 4+ messages in thread From: Junio C Hamano @ 2013-12-30 19:01 UTC (permalink / raw) To: Василий Макаров Cc: git, jrnieder Василий Макаров <einmalfel@gmail•com> writes: > Hi there! > First of all: I'm new to mailing-lists, sorry if I'm doing it wrong. > > I've found a bug in git merge-base, causing it to show not best common > ancestors and duplicates under some circumstances (example is given in > attached test case). Attached??? > Problem cause is algorithm used in get_octopus_merge_bases(), it > iteratively concatenates merge bases, and don't care if there are > duplicates or decsendants/ancestors in result. > What I suggest as a solution is to simply reduce bases list after > get_octopus_merge_bases(). I do not offhand remember if it was deliberate that we do not dedup the result from the underlying get_octopus_merge_bases() (the most likely reason for not deduping is because the caller is expected to do that if it wants to). Whether it is an improvement to force deduping here or it is an regression to do so, I think we should split that helper function handle_octopus(). It does two totally unrelated things (one is only to list independent heads without showing merge bases, the other is to show one or more merge bases across all the heads given). Perhaps if we split the "independent" codepath introduced by a1e0ad78 (merge-base --independent to print reduced parent list in a merge, 2010-08-17) into its own helper function, like this, it would make it clear what is going on. Thanks. builtin/merge-base.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/builtin/merge-base.c b/builtin/merge-base.c index e88eb93..a00e8f5 100644 --- a/builtin/merge-base.c +++ b/builtin/merge-base.c @@ -44,19 +44,36 @@ static struct commit *get_commit_reference(const char *arg) return r; } -static int handle_octopus(int count, const char **args, int reduce, int show_all) +static int handle_independent(int count, const char **args) { struct commit_list *revs = NULL; struct commit_list *result; int i; - if (reduce) - show_all = 1; + for (i = count - 1; i >= 0; i--) + commit_list_insert(get_commit_reference(args[i]), &revs); + + result = reduce_heads(revs); + if (!result) + return 1; + + while (result) { + printf("%s\n", sha1_to_hex(result->item->object.sha1)); + result = result->next; + } + return 0; +} + +static int handle_octopus(int count, const char **args, int show_all) +{ + struct commit_list *revs = NULL; + struct commit_list *result; + int i; for (i = count - 1; i >= 0; i--) commit_list_insert(get_commit_reference(args[i]), &revs); - result = reduce ? reduce_heads(revs) : get_octopus_merge_bases(revs); + result = get_octopus_merge_bases(revs); if (!result) return 1; @@ -114,8 +131,10 @@ int cmd_merge_base(int argc, const char **argv, const char *prefix) if (reduce && (show_all || octopus)) die("--independent cannot be used with other options"); - if (octopus || reduce) - return handle_octopus(argc, argv, reduce, show_all); + if (octopus) + return handle_octopus(argc, argv, show_all); + else if (reduce) + return handle_independent(argc, argv); rev = xmalloc(argc * sizeof(*rev)); while (argc-- > 0) ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] merge-base: fix duplicates and not best ancestors in output 2013-12-30 19:01 ` Junio C Hamano @ 2013-12-30 20:06 ` Junio C Hamano 2013-12-31 11:15 ` Василий Макаров 0 siblings, 1 reply; 4+ messages in thread From: Junio C Hamano @ 2013-12-30 20:06 UTC (permalink / raw) To: Василий Макаров Cc: git, jrnieder Junio C Hamano <gitster@pobox•com> writes: > I do not offhand remember if it was deliberate that we do not dedup > the result from the underlying get_octopus_merge_bases() (the most > likely reason for not deduping is because the caller is expected to > do that if it wants to). > > Whether it is an improvement to force deduping here or it is an > regression to do so, I think we should split that helper function > handle_octopus(). It does two totally unrelated things (one is only > to list independent heads without showing merge bases, the other is > to show one or more merge bases across all the heads given). > Perhaps if we split the "independent" codepath introduced by > a1e0ad78 (merge-base --independent to print reduced parent list in a > merge, 2010-08-17) into its own helper function, like this, it would > make it clear what is going on. And assuming that deduping is the right thing to do here, here is a follow-up on top of the spliting patch. -- >8 -- Subject: [PATCH] merge-base --octopus: reduce the result from get_octopus_merge_bases() Scripts that use "merge-base --octopus" could do the reducing themselves, but most of them are expected to want to get the reduced results without having to do any work themselves. Tests are taken from a message by Василий Макаров <einmalfel@gmail•com> Signed-off-by: Junio C Hamano <gitster@pobox•com> --- We might want to vet the existing callers of the underlying get_octopus_merge_bases() and find out if _all_ of them are doing anything extra (like deduping) because the machinery can return duplicate results. And if that is the case, then we may want to move the dedupling down the callchain instead of having it here. builtin/merge-base.c | 2 +- t/t6010-merge-base.sh | 39 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 1 deletion(-) diff --git a/builtin/merge-base.c b/builtin/merge-base.c index daa96c7..87f4dbc 100644 --- a/builtin/merge-base.c +++ b/builtin/merge-base.c @@ -73,7 +73,7 @@ static int handle_octopus(int count, const char **args, int show_all) for (i = count - 1; i >= 0; i--) commit_list_insert(get_commit_reference(args[i]), &revs); - result = get_octopus_merge_bases(revs); + result = reduce_heads(get_octopus_merge_bases(revs)); if (!result) return 1; diff --git a/t/t6010-merge-base.sh b/t/t6010-merge-base.sh index f80bba8..abb5728 100755 --- a/t/t6010-merge-base.sh +++ b/t/t6010-merge-base.sh @@ -230,4 +230,43 @@ test_expect_success 'criss-cross merge-base for octopus-step' ' test_cmp expected.sorted actual.sorted ' +test_expect_success 'merge-base --octopus --all for complex tree' ' + # Best common ancestor for JE, JAA and JDD is JC + # JE + # / | + # / | + # / | + # JAA / | + # |\ / | + # | \ | JDD | + # | \ |/ | | + # | JC JD | + # | | /| | + # | |/ | | + # JA | | | + # |\ /| | | + # X JB | X X + # \ \ | / / + # \__\|/___/ + # J + test_commit J && + test_commit JB && + git reset --hard J && + test_commit JC && + git reset --hard J && + test_commit JTEMP1 && + test_merge JA JB && + test_merge JAA JC && + git reset --hard J && + test_commit JTEMP2 && + test_merge JD JB && + test_merge JDD JC && + git reset --hard J && + test_commit JTEMP3 && + test_merge JE JC && + git rev-parse JC >expected && + git merge-base --all --octopus JAA JDD JE >actual && + test_cmp expected actual +' + test_done -- 1.8.5.2-311-g6427a96 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] merge-base: fix duplicates and not best ancestors in output 2013-12-30 20:06 ` Junio C Hamano @ 2013-12-31 11:15 ` Василий Макаров 0 siblings, 0 replies; 4+ messages in thread From: Василий Макаров @ 2013-12-31 11:15 UTC (permalink / raw) To: git; +Cc: Jonathan Nieder Hello, Junio! >> Hi there! >> First of all: I'm new to mailing-lists, sorry if I'm doing it wrong. >> >> I've found a bug in git merge-base, causing it to show not best common >> ancestors and duplicates under some circumstances (example is given in >> attached test case). > >Attached??? Sorry about this. I expected my first message to be sent back to me by git@vger•kernel.org. As I understand I should have replied to this message with second patch (test). But I did not received first message back, so I just sent second one to git@vger•kernel.org. What am I doing wrong? > I think we should split that helper function > handle_octopus(). It does two totally unrelated things Agree! I have not done this in original patch because I wanted it to be a minimal change. > And assuming that deduping is the right thing to do here, here is a > follow-up on top of the spliting patch. > > Scripts that use "merge-base --octopus" could do the reducing > themselves, but most of them are expected to want to get the reduced > results without having to do any work themselves. Not sure what scripts you are talking about. Man git merge-base says: "--octopus Compute the best common ancestors of all supplied commits" Without deduping this option doesn't always work, so it is a right thing to do here. I've also tested changes you've sent, they are OK. Happy new year! 2013/12/31 Junio C Hamano <gitster@pobox•com>: > Junio C Hamano <gitster@pobox•com> writes: > >> I do not offhand remember if it was deliberate that we do not dedup >> the result from the underlying get_octopus_merge_bases() (the most >> likely reason for not deduping is because the caller is expected to >> do that if it wants to). >> >> Whether it is an improvement to force deduping here or it is an >> regression to do so, I think we should split that helper function >> handle_octopus(). It does two totally unrelated things (one is only >> to list independent heads without showing merge bases, the other is >> to show one or more merge bases across all the heads given). >> Perhaps if we split the "independent" codepath introduced by >> a1e0ad78 (merge-base --independent to print reduced parent list in a >> merge, 2010-08-17) into its own helper function, like this, it would >> make it clear what is going on. > > And assuming that deduping is the right thing to do here, here is a > follow-up on top of the spliting patch. > > -- >8 -- > Subject: [PATCH] merge-base --octopus: reduce the result from get_octopus_merge_bases() > > Scripts that use "merge-base --octopus" could do the reducing > themselves, but most of them are expected to want to get the reduced > results without having to do any work themselves. > > Tests are taken from a message by Василий Макаров > <einmalfel@gmail•com> > > Signed-off-by: Junio C Hamano <gitster@pobox•com> > --- > > We might want to vet the existing callers of the underlying > get_octopus_merge_bases() and find out if _all_ of them are doing > anything extra (like deduping) because the machinery can return > duplicate results. And if that is the case, then we may want to > move the dedupling down the callchain instead of having it here. > > builtin/merge-base.c | 2 +- > t/t6010-merge-base.sh | 39 +++++++++++++++++++++++++++++++++++++++ > 2 files changed, 40 insertions(+), 1 deletion(-) > > diff --git a/builtin/merge-base.c b/builtin/merge-base.c > index daa96c7..87f4dbc 100644 > --- a/builtin/merge-base.c > +++ b/builtin/merge-base.c > @@ -73,7 +73,7 @@ static int handle_octopus(int count, const char **args, int show_all) > for (i = count - 1; i >= 0; i--) > commit_list_insert(get_commit_reference(args[i]), &revs); > > - result = get_octopus_merge_bases(revs); > + result = reduce_heads(get_octopus_merge_bases(revs)); > > if (!result) > return 1; > diff --git a/t/t6010-merge-base.sh b/t/t6010-merge-base.sh > index f80bba8..abb5728 100755 > --- a/t/t6010-merge-base.sh > +++ b/t/t6010-merge-base.sh > @@ -230,4 +230,43 @@ test_expect_success 'criss-cross merge-base for octopus-step' ' > test_cmp expected.sorted actual.sorted > ' > > +test_expect_success 'merge-base --octopus --all for complex tree' ' > + # Best common ancestor for JE, JAA and JDD is JC > + # JE > + # / | > + # / | > + # / | > + # JAA / | > + # |\ / | > + # | \ | JDD | > + # | \ |/ | | > + # | JC JD | > + # | | /| | > + # | |/ | | > + # JA | | | > + # |\ /| | | > + # X JB | X X > + # \ \ | / / > + # \__\|/___/ > + # J > + test_commit J && > + test_commit JB && > + git reset --hard J && > + test_commit JC && > + git reset --hard J && > + test_commit JTEMP1 && > + test_merge JA JB && > + test_merge JAA JC && > + git reset --hard J && > + test_commit JTEMP2 && > + test_merge JD JB && > + test_merge JDD JC && > + git reset --hard J && > + test_commit JTEMP3 && > + test_merge JE JC && > + git rev-parse JC >expected && > + git merge-base --all --octopus JAA JDD JE >actual && > + test_cmp expected actual > +' > + > test_done > -- > 1.8.5.2-311-g6427a96 > ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-12-31 11:16 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-12-28 10:22 [PATCH 1/2] merge-base: fix duplicates and not best ancestors in output Василий Макаров 2013-12-30 19:01 ` Junio C Hamano 2013-12-30 20:06 ` Junio C Hamano 2013-12-31 11:15 ` Василий Макаров
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