# [PATCH] revision: fix --left/right-only use with unrelated histories 9 messages from 2025-03-30 to 2025-04-11. Participants: Matt Hunter, Johannes Sixt, Phillip Wood, Junio C Hamano, phillip.wood123@gmail.com. Thread: https://gitlist.dev/t/63215 ## Matt Hunter, 2025-03-30 05:49 Subject: [PATCH] revision: fix --left/right-only use with unrelated histories Message-ID: <20250330055809.1019090-1-m@lfurio.us> URL: https://gitlist.dev/e/20250330055809.1019090-1-m%40lfurio.us ``` This is a similar fix as 023756f4eb (revision walker: --cherry-pick is a limited operation), but for the --left-only and --right-only options. When computing a symmetric difference between two unrelated histories, no suitable merge base exists, and so no boundary commit is flagged as UNINTERESTING. Previously, we relied on the presence of such boundary to trigger limiting and thus consideration of either "revs->left_only" or "revs->right_only". A number of other entries in the option parser have started including overrides for "revs->limited = 1". Do the same for these options. Signed-off-by: Matt Hunter --- Patch applies to the current maint branch (git v2.49.0). I made a best guess at what the most logical home for this test case should be, so please let me know if somewhere else is preferred. All tests pass when this is cherry-picked to seen. There is only a minor conflict, as a few different tests have appeared in this same spot. revision.c | 2 ++ t/t6000-rev-list-misc.sh | 12 ++++++++++++ 2 files changed, 14 insertions(+) diff --git a/revision.c b/revision.c index c4390f0938..e045445bc3 100644 --- a/revision.c +++ b/revision.c @@ -2488,10 +2488,12 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg die(_("options '%s' and '%s' cannot be used together"), "--left-only", "--right-only/--cherry"); revs->left_only = 1; + revs->limited = 1; } else if (!strcmp(arg, "--right-only")) { if (revs->left_only) die(_("options '%s' and '%s' cannot be used together"), "--right-only", "--left-only"); revs->right_only = 1; + revs->limited = 1; } else if (!strcmp(arg, "--cherry")) { if (revs->left_only) die(_("options '%s' and '%s' cannot be used together"), "--cherry", "--left-only"); diff --git a/t/t6000-rev-list-misc.sh b/t/t6000-rev-list-misc.sh index 6289a2e8b0..58f1f746e0 100755 --- a/t/t6000-rev-list-misc.sh +++ b/t/t6000-rev-list-misc.sh @@ -182,4 +182,16 @@ test_expect_success 'rev-list --unpacked' ' test_cmp expect actual ' +test_expect_success 'rev-list one-sided unrelated symmetric diff' ' + test_tick && + git commit --allow-empty -m xyz && + git branch cmp && + git rebase --force-rebase --root && + + git rev-list --left-only HEAD...cmp >head && + git rev-list --right-only HEAD...cmp >cmp && + + test $(comm -12 <(sort head) <(sort cmp) | wc -l) = "0" +' + test_done base-commit: 683c54c999c301c2cd6f715c411407c413b1d84e -- 2.49.0 ``` ## Johannes Sixt, 2025-03-30 08:31 Subject: Re: [PATCH] revision: fix --left/right-only use with unrelated histories Message-ID: <644ce9b5-755c-4faf-aaf8-b0383e12ff64@kdbg.org> URL: https://gitlist.dev/e/644ce9b5-755c-4faf-aaf8-b0383e12ff64%40kdbg.org In-Reply-To: <20250330055809.1019090-1-m@lfurio.us> ``` Am 30.03.25 um 07:49 schrieb Matt Hunter: > + test $(comm -12 <(sort head) <(sort cmp) | wc -l) = "0" Process substitution does not work on Windows. Please use temporary files. -- Hannes ``` ## Phillip Wood, 2025-03-30 10:11 Subject: Re: [PATCH] revision: fix --left/right-only use with unrelated histories Message-ID: URL: https://gitlist.dev/e/f8a7d089-3150-4212-8ad0-c9bbb3858776%40gmail.com In-Reply-To: <20250330055809.1019090-1-m@lfurio.us> ``` Hi Matt On 30/03/2025 06:49, Matt Hunter wrote: > +test_expect_success 'rev-list one-sided unrelated symmetric diff' ' > + test_tick && > + git commit --allow-empty -m xyz && > + git branch cmp && > + git rebase --force-rebase --root && > + > + git rev-list --left-only HEAD...cmp >head && > + git rev-list --right-only HEAD...cmp >cmp && > + > + test $(comm -12 <(sort head) <(sort cmp) | wc -l) = "0" Thank you for adding a test. We have a helper function test_line_count which provides a helpful debugging message if the comparison fails. Using that and avoiding process substitutions we'd write sort head >sorted_head && sort cmp >sorted_cmp && comm -12 sorted_head sorted_cmp >actual && test_line_count = 0 actual Thanks Phillip > + > test_done > > base-commit: 683c54c999c301c2cd6f715c411407c413b1d84e ``` ## Matt Hunter, 2025-03-30 10:54 Subject: Re: [PATCH] revision: fix --left/right-only use with unrelated histories Message-ID: URL: https://gitlist.dev/e/D8TJMUMOGLBC.3FR8DHTTUN4M9%40lfurio.us In-Reply-To: ``` On Sun Mar 30, 2025 at 6:11 AM EDT, Phillip Wood wrote: > Thank you for adding a test. We have a helper function test_line_count > which provides a helpful debugging message if the comparison fails. > Using that and avoiding process substitutions we'd write > > sort head >sorted_head && > sort cmp >sorted_cmp && > comm -12 sorted_head sorted_cmp >actual && > test_line_count = 0 actual Thanks for that helper tip. I was just about to send a v2 when your message came in, so I'm getting that incorporated now. By the way, I had originally wanted to write test assertions that checked the actual number of commit ids returned from each of the two calls to rev-list - something like: git rev-list --X-only HEAD...cmp >file && test_line_count = N file But since I'm not very familiar with this test harness yet, I couldn't actually figure the correct value for N. It's not 1 (the commit made in my test body), and it's not 2 (that commit, plus the one from the setup case at the top of the file). Any appropriate higher value wasn't obvious. So I switched to what you saw in my v1. Maybe this "no commit ids in common" test is actually the stronger assertion? ``` ## Matt Hunter, 2025-03-30 11:24 Subject: [PATCH v2] revision: fix --left/right-only use with unrelated histories Message-ID: <20250330112850.2477673-1-m@lfurio.us> URL: https://gitlist.dev/e/20250330112850.2477673-1-m%40lfurio.us In-Reply-To: <20250330055809.1019090-1-m@lfurio.us> ``` This is a similar fix as 023756f4eb (revision walker: --cherry-pick is a limited operation), but for the --left-only and --right-only options. When computing a symmetric difference between two unrelated histories, no suitable merge base exists, and so no boundary commit is flagged as UNINTERESTING. Previously, we relied on the presence of such boundary to trigger limiting and thus consideration of either "revs->left_only" or "revs->right_only". A number of other entries in the option parser have started including overrides for "revs->limited = 1". Do the same for these options. Signed-off-by: Matt Hunter --- Range-diff against v1: 1: 1982f14d70 ! 1: 4f5b264b26 revision: fix --left/right-only use with unrelated histories @@ t/t6000-rev-list-misc.sh: test_expect_success 'rev-list --unpacked' ' + git rev-list --left-only HEAD...cmp >head && + git rev-list --right-only HEAD...cmp >cmp && + -+ test $(comm -12 <(sort head) <(sort cmp) | wc -l) = "0" ++ sort head >head.sorted && ++ sort cmp >cmp.sorted && ++ comm -12 head.sorted cmp.sorted >actual && ++ test_line_count = 0 actual +' + test_done base-commit: 683c54c999c301c2cd6f715c411407c413b1d84e revision.c | 2 ++ t/t6000-rev-list-misc.sh | 15 +++++++++++++++ 2 files changed, 17 insertions(+) diff --git a/revision.c b/revision.c index c4390f0938..e045445bc3 100644 --- a/revision.c +++ b/revision.c @@ -2488,10 +2488,12 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg die(_("options '%s' and '%s' cannot be used together"), "--left-only", "--right-only/--cherry"); revs->left_only = 1; + revs->limited = 1; } else if (!strcmp(arg, "--right-only")) { if (revs->left_only) die(_("options '%s' and '%s' cannot be used together"), "--right-only", "--left-only"); revs->right_only = 1; + revs->limited = 1; } else if (!strcmp(arg, "--cherry")) { if (revs->left_only) die(_("options '%s' and '%s' cannot be used together"), "--cherry", "--left-only"); diff --git a/t/t6000-rev-list-misc.sh b/t/t6000-rev-list-misc.sh index 6289a2e8b0..d338f7ecb4 100755 --- a/t/t6000-rev-list-misc.sh +++ b/t/t6000-rev-list-misc.sh @@ -182,4 +182,19 @@ test_expect_success 'rev-list --unpacked' ' test_cmp expect actual ' +test_expect_success 'rev-list one-sided unrelated symmetric diff' ' + test_tick && + git commit --allow-empty -m xyz && + git branch cmp && + git rebase --force-rebase --root && + + git rev-list --left-only HEAD...cmp >head && + git rev-list --right-only HEAD...cmp >cmp && + + sort head >head.sorted && + sort cmp >cmp.sorted && + comm -12 head.sorted cmp.sorted >actual && + test_line_count = 0 actual +' + test_done -- 2.49.0 ``` ## Junio C Hamano, 2025-04-01 09:56 Subject: Re: [PATCH] revision: fix --left/right-only use with unrelated histories Message-ID: URL: https://gitlist.dev/e/xmqqwmc49pcl.fsf%40gitster.g In-Reply-To: <644ce9b5-755c-4faf-aaf8-b0383e12ff64@kdbg.org> ``` Johannes Sixt writes: > Am 30.03.25 um 07:49 schrieb Matt Hunter: >> + test $(comm -12 <(sort head) <(sort cmp) | wc -l) = "0" > > Process substitution does not work on Windows. Please use temporary files. Also it is not portable across POSIX compilant shells (IIRC it is a bash-ism). ``` ## phillip.wood123@gmail.com, 2025-04-02 13:12 Subject: Re: [PATCH] revision: fix --left/right-only use with unrelated histories Message-ID: <63e79534-db09-444f-8e82-8e01d914182d@gmail.com> URL: https://gitlist.dev/e/63e79534-db09-444f-8e82-8e01d914182d%40gmail.com In-Reply-To: ``` Hi Matt On 30/03/2025 11:54, Matt Hunter wrote: > On Sun Mar 30, 2025 at 6:11 AM EDT, Phillip Wood wrote: >> Thank you for adding a test. We have a helper function test_line_count >> which provides a helpful debugging message if the comparison fails. >> Using that and avoiding process substitutions we'd write >> >> sort head >sorted_head && >> sort cmp >sorted_cmp && >> comm -12 sorted_head sorted_cmp >actual && >> test_line_count = 0 actual > Thanks for that helper tip. I was just about to send a v2 when your > message came in, so I'm getting that incorporated now. > > By the way, I had originally wanted to write test assertions that > checked the actual number of commit ids returned from each of the two > calls to rev-list - something like: > > git rev-list --X-only HEAD...cmp >file && > test_line_count = N file > > But since I'm not very familiar with this test harness yet, I couldn't > actually figure the correct value for N. It's not 1 (the commit made in > my test body), and it's not 2 (that commit, plus the one from the setup > case at the top of the file). Any appropriate higher value wasn't > obvious. Each test in a given file runs in the same repository (this is a performance optimization) so the number of commits will depend on what the previous tests have done. Usually there is a setup test at the start of the file which creates some commits with tags. Individual tests can then use those tags to establish a known state. Best Wishes Phillip > So I switched to what you saw in my v1. Maybe this "no commit ids in > common" test is actually the stronger assertion? ``` ## Matt Hunter, 2025-04-04 05:13 Subject: Re: [PATCH] revision: fix --left/right-only use with unrelated histories Message-ID: URL: https://gitlist.dev/e/D8XLIW3UYCGC.1S3K2HXJ2R8BL%40lfurio.us In-Reply-To: <63e79534-db09-444f-8e82-8e01d914182d@gmail.com> ``` On Wed Apr 2, 2025 at 9:12 AM EDT, phillip.wood123 wrote: > Each test in a given file runs in the same repository (this is a > performance optimization) so the number of commits will depend on what > the previous tests have done. Usually there is a setup test at the start > of the file which creates some commits with tags. Individual tests can > then use those tags to establish a known state. Ok - that makes sense. And that being the case, I think I stand by the test in v2 of my patch. Thanks ``` ## Junio C Hamano, 2025-04-11 14:41 Subject: Re: [PATCH v2] revision: fix --left/right-only use with unrelated histories Message-ID: URL: https://gitlist.dev/e/xmqqecxyoj4a.fsf%40gitster.g In-Reply-To: <20250330112850.2477673-1-m@lfurio.us> ``` Matt Hunter writes: > This is a similar fix as 023756f4eb (revision walker: --cherry-pick is a > limited operation), but for the --left-only and --right-only options. > > When computing a symmetric difference between two unrelated histories, > no suitable merge base exists, and so no boundary commit is flagged as > UNINTERESTING. Previously, we relied on the presence of such boundary > to trigger limiting and thus consideration of either "revs->left_only" > or "revs->right_only". > > A number of other entries in the option parser have started including > overrides for "revs->limited = 1". Do the same for these options. > > Signed-off-by: Matt Hunter > --- Thanks. As far as I can see, the whole patch looks sensible, including its rewritten tests. Let me mark the topic for 'next'. Thanks, all. > Range-diff against v1: > 1: 1982f14d70 ! 1: 4f5b264b26 revision: fix --left/right-only use with unrelated histories > @@ t/t6000-rev-list-misc.sh: test_expect_success 'rev-list --unpacked' ' > + git rev-list --left-only HEAD...cmp >head && > + git rev-list --right-only HEAD...cmp >cmp && > + > -+ test $(comm -12 <(sort head) <(sort cmp) | wc -l) = "0" > ++ sort head >head.sorted && > ++ sort cmp >cmp.sorted && > ++ comm -12 head.sorted cmp.sorted >actual && > ++ test_line_count = 0 actual > +' > + > test_done > > base-commit: 683c54c999c301c2cd6f715c411407c413b1d84e > > revision.c | 2 ++ > t/t6000-rev-list-misc.sh | 15 +++++++++++++++ > 2 files changed, 17 insertions(+) > > diff --git a/revision.c b/revision.c > index c4390f0938..e045445bc3 100644 > --- a/revision.c > +++ b/revision.c > @@ -2488,10 +2488,12 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg > die(_("options '%s' and '%s' cannot be used together"), > "--left-only", "--right-only/--cherry"); > revs->left_only = 1; > + revs->limited = 1; > } else if (!strcmp(arg, "--right-only")) { > if (revs->left_only) > die(_("options '%s' and '%s' cannot be used together"), "--right-only", "--left-only"); > revs->right_only = 1; > + revs->limited = 1; > } else if (!strcmp(arg, "--cherry")) { > if (revs->left_only) > die(_("options '%s' and '%s' cannot be used together"), "--cherry", "--left-only"); > diff --git a/t/t6000-rev-list-misc.sh b/t/t6000-rev-list-misc.sh > index 6289a2e8b0..d338f7ecb4 100755 > --- a/t/t6000-rev-list-misc.sh > +++ b/t/t6000-rev-list-misc.sh > @@ -182,4 +182,19 @@ test_expect_success 'rev-list --unpacked' ' > test_cmp expect actual > ' > > +test_expect_success 'rev-list one-sided unrelated symmetric diff' ' > + test_tick && > + git commit --allow-empty -m xyz && > + git branch cmp && > + git rebase --force-rebase --root && > + > + git rev-list --left-only HEAD...cmp >head && > + git rev-list --right-only HEAD...cmp >cmp && > + > + sort head >head.sorted && > + sort cmp >cmp.sorted && > + comm -12 head.sorted cmp.sorted >actual && > + test_line_count = 0 actual > +' > + > test_done ```