git/t/t3425-rebase-topology-merges.sh

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#!/bin/sh
test_description='rebase topology tests with merges'
. ./test-lib.sh
. "$TEST_DIRECTORY"/lib-rebase.sh
test_revision_subjects () {
expected="$1"
shift
set -- $(git log --format=%s --no-walk=unsorted "$@")
test "$expected" = "$*"
}
# a---b-----------c
# \ \
# d-------e \
# \ \ \
# n---o---w---v
# \
# z
test_expect_success 'setup of non-linear-history' '
test_commit a &&
test_commit b &&
test_commit c &&
git checkout b &&
test_commit d &&
test_commit e &&
git checkout c &&
test_commit g &&
revert h g &&
git checkout d &&
cherry_pick gp g &&
test_commit i &&
git checkout b &&
test_commit f &&
git checkout d &&
test_commit n &&
test_commit o &&
test_merge w e &&
test_merge v c &&
git checkout o &&
test_commit z
'
test_run_rebase () {
result=$1
shift
test_expect_$result "rebase $* after merge from upstream" "
reset_rebase &&
git rebase $* e w &&
test_cmp_rev e HEAD~2 &&
test_linear_range 'n o' e..
"
}
rebase: rename the two primary rebase backends Two related changes, with separate rationale for each: Rename the 'interactive' backend to 'merge' because: * 'interactive' as a name caused confusion; this backend has been used for many kinds of non-interactive rebases, and will probably be used in the future for more non-interactive rebases than interactive ones given that we are making it the default. * 'interactive' is not the underlying strategy; merging is. * the directory where state is stored is not called .git/rebase-interactive but .git/rebase-merge. Rename the 'am' backend to 'apply' because: * Few users are familiar with git-am as a reference point. * Related to the above, the name 'am' makes sentences in the documentation harder for users to read and comprehend (they may read it as the verb from "I am"); avoiding this difficult places a large burden on anyone writing documentation about this backend to be very careful with quoting and sentence structure and often forces annoying redundancy to try to avoid such problems. * Users stumble over pronunciation ("am" as in "I am a person not a backend" or "am" as in "the first and thirteenth letters in the alphabet in order are "A-M"); this may drive confusion when one user tries to explain to another what they are doing. * While "am" is the tool driving this backend, the tool driving git-am is git-apply, and since we are driving towards lower-level tools for the naming of the merge backend we may as well do so here too. * The directory where state is stored has never been called .git/rebase-am, it was always called .git/rebase-apply. For all the reasons listed above: * Modify the documentation to refer to the backends with the new names * Provide a brief note in the documentation connecting the new names to the old names in case users run across the old names anywhere (e.g. in old release notes or older versions of the documentation) * Change the (new) --am command line flag to --apply * Rename some enums, variables, and functions to reinforce the new backend names for us as well. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-15 21:36:41 +00:00
test_run_rebase success --apply
test_run_rebase success -m
test_run_rebase success -i
test_run_rebase () {
result=$1
shift
expected=$1
shift
test_expect_$result "rebase $* of non-linear history is linearized in place" "
reset_rebase &&
git rebase $* d w &&
test_cmp_rev d HEAD~3 &&
test_linear_range "\'"$expected"\'" d..
"
}
rebase: rename the two primary rebase backends Two related changes, with separate rationale for each: Rename the 'interactive' backend to 'merge' because: * 'interactive' as a name caused confusion; this backend has been used for many kinds of non-interactive rebases, and will probably be used in the future for more non-interactive rebases than interactive ones given that we are making it the default. * 'interactive' is not the underlying strategy; merging is. * the directory where state is stored is not called .git/rebase-interactive but .git/rebase-merge. Rename the 'am' backend to 'apply' because: * Few users are familiar with git-am as a reference point. * Related to the above, the name 'am' makes sentences in the documentation harder for users to read and comprehend (they may read it as the verb from "I am"); avoiding this difficult places a large burden on anyone writing documentation about this backend to be very careful with quoting and sentence structure and often forces annoying redundancy to try to avoid such problems. * Users stumble over pronunciation ("am" as in "I am a person not a backend" or "am" as in "the first and thirteenth letters in the alphabet in order are "A-M"); this may drive confusion when one user tries to explain to another what they are doing. * While "am" is the tool driving this backend, the tool driving git-am is git-apply, and since we are driving towards lower-level tools for the naming of the merge backend we may as well do so here too. * The directory where state is stored has never been called .git/rebase-am, it was always called .git/rebase-apply. For all the reasons listed above: * Modify the documentation to refer to the backends with the new names * Provide a brief note in the documentation connecting the new names to the old names in case users run across the old names anywhere (e.g. in old release notes or older versions of the documentation) * Change the (new) --am command line flag to --apply * Rename some enums, variables, and functions to reinforce the new backend names for us as well. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-15 21:36:41 +00:00
test_run_rebase success 'n o e' --apply
rebase: define linearization ordering and enforce it Ever since commit 3f213981e44a ("add tests for rebasing merged history", 2013-06-06), t3425 has had tests which included the rebasing of merged history and whose order of applied commits was checked. Unfortunately, the tests expected different behavior depending on which backend was in use. Implementing these checks was the following four lines (including the TODO message) which were repeated verbatim three times in t3425: #TODO: make order consistent across all flavors of rebase test_run_rebase success 'e n o' '' test_run_rebase success 'e n o' -m test_run_rebase success 'n o e' -i As part of the effort to reduce differences between the rebase backends so that users get more uniform behavior, let's define the correct behavior and modify the different backends so they all get the right answer. It turns out that the difference in behavior here is entirely due to topological sorting; since some backends require topological sorting (particularly when --rebase-merges is specified), require it for all modes. Modify the am and merge backends to implement this. Performance Considerations: I was unable to measure any appreciable performance difference with this change. Trying to control the run-to-run variation was difficult; I eventually found a headless beefy box that I could ssh into, which seemed to help. Using git.git, I ran the following testcase: $ git reset --hard v2.20.0-rc1~2 $ time git rebase --quiet v2.20.0-rc0~16 I first ran once to warm any disk caches, then ran five subsequent runs and recorded the times of those five. I observed the following results for the average time: Before this change: "real" timing: 1.340s (standard deviation: 0.040s) "user" timing: 1.050s (standard deviation: 0.041s) "sys" timing: 0.270s (standard deviation: 0.011s) After this change: "real" timing: 1.327s (standard deviation: 0.065s) "user" timing: 1.031s (standard deviation: 0.061s) "sys" timing: 0.280s (standard deviation: 0.014s) Measurements aside, I would expect the timing for walking revisions to be dwarfed by the work involved in creating and applying patches, so this isn't too surprising. Further, while somewhat counter-intuitive, it is possible that turning on topological sorting is actually a performance improvement: by way of comparison, turning on --topo-order made fast-export faster (see https://public-inbox.org/git/20090211135640.GA19600@coredump.intra.peff.net/). Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-11 16:11:38 +00:00
test_run_rebase success 'n o e' -m
test_run_rebase success 'n o e' -i
test_run_rebase () {
result=$1
shift
expected=$1
shift
test_expect_$result "rebase $* of non-linear history is linearized upstream" "
reset_rebase &&
git rebase $* c w &&
test_cmp_rev c HEAD~4 &&
test_linear_range "\'"$expected"\'" c..
"
}
rebase: rename the two primary rebase backends Two related changes, with separate rationale for each: Rename the 'interactive' backend to 'merge' because: * 'interactive' as a name caused confusion; this backend has been used for many kinds of non-interactive rebases, and will probably be used in the future for more non-interactive rebases than interactive ones given that we are making it the default. * 'interactive' is not the underlying strategy; merging is. * the directory where state is stored is not called .git/rebase-interactive but .git/rebase-merge. Rename the 'am' backend to 'apply' because: * Few users are familiar with git-am as a reference point. * Related to the above, the name 'am' makes sentences in the documentation harder for users to read and comprehend (they may read it as the verb from "I am"); avoiding this difficult places a large burden on anyone writing documentation about this backend to be very careful with quoting and sentence structure and often forces annoying redundancy to try to avoid such problems. * Users stumble over pronunciation ("am" as in "I am a person not a backend" or "am" as in "the first and thirteenth letters in the alphabet in order are "A-M"); this may drive confusion when one user tries to explain to another what they are doing. * While "am" is the tool driving this backend, the tool driving git-am is git-apply, and since we are driving towards lower-level tools for the naming of the merge backend we may as well do so here too. * The directory where state is stored has never been called .git/rebase-am, it was always called .git/rebase-apply. For all the reasons listed above: * Modify the documentation to refer to the backends with the new names * Provide a brief note in the documentation connecting the new names to the old names in case users run across the old names anywhere (e.g. in old release notes or older versions of the documentation) * Change the (new) --am command line flag to --apply * Rename some enums, variables, and functions to reinforce the new backend names for us as well. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-15 21:36:41 +00:00
test_run_rebase success 'd n o e' --apply
rebase: define linearization ordering and enforce it Ever since commit 3f213981e44a ("add tests for rebasing merged history", 2013-06-06), t3425 has had tests which included the rebasing of merged history and whose order of applied commits was checked. Unfortunately, the tests expected different behavior depending on which backend was in use. Implementing these checks was the following four lines (including the TODO message) which were repeated verbatim three times in t3425: #TODO: make order consistent across all flavors of rebase test_run_rebase success 'e n o' '' test_run_rebase success 'e n o' -m test_run_rebase success 'n o e' -i As part of the effort to reduce differences between the rebase backends so that users get more uniform behavior, let's define the correct behavior and modify the different backends so they all get the right answer. It turns out that the difference in behavior here is entirely due to topological sorting; since some backends require topological sorting (particularly when --rebase-merges is specified), require it for all modes. Modify the am and merge backends to implement this. Performance Considerations: I was unable to measure any appreciable performance difference with this change. Trying to control the run-to-run variation was difficult; I eventually found a headless beefy box that I could ssh into, which seemed to help. Using git.git, I ran the following testcase: $ git reset --hard v2.20.0-rc1~2 $ time git rebase --quiet v2.20.0-rc0~16 I first ran once to warm any disk caches, then ran five subsequent runs and recorded the times of those five. I observed the following results for the average time: Before this change: "real" timing: 1.340s (standard deviation: 0.040s) "user" timing: 1.050s (standard deviation: 0.041s) "sys" timing: 0.270s (standard deviation: 0.011s) After this change: "real" timing: 1.327s (standard deviation: 0.065s) "user" timing: 1.031s (standard deviation: 0.061s) "sys" timing: 0.280s (standard deviation: 0.014s) Measurements aside, I would expect the timing for walking revisions to be dwarfed by the work involved in creating and applying patches, so this isn't too surprising. Further, while somewhat counter-intuitive, it is possible that turning on topological sorting is actually a performance improvement: by way of comparison, turning on --topo-order made fast-export faster (see https://public-inbox.org/git/20090211135640.GA19600@coredump.intra.peff.net/). Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-11 16:11:38 +00:00
test_run_rebase success 'd n o e' -m
test_run_rebase success 'd n o e' -i
test_run_rebase () {
result=$1
shift
expected=$1
shift
test_expect_$result "rebase $* of non-linear history with merges after upstream merge is linearized" "
reset_rebase &&
git rebase $* c v &&
test_cmp_rev c HEAD~4 &&
test_linear_range "\'"$expected"\'" c..
"
}
rebase: rename the two primary rebase backends Two related changes, with separate rationale for each: Rename the 'interactive' backend to 'merge' because: * 'interactive' as a name caused confusion; this backend has been used for many kinds of non-interactive rebases, and will probably be used in the future for more non-interactive rebases than interactive ones given that we are making it the default. * 'interactive' is not the underlying strategy; merging is. * the directory where state is stored is not called .git/rebase-interactive but .git/rebase-merge. Rename the 'am' backend to 'apply' because: * Few users are familiar with git-am as a reference point. * Related to the above, the name 'am' makes sentences in the documentation harder for users to read and comprehend (they may read it as the verb from "I am"); avoiding this difficult places a large burden on anyone writing documentation about this backend to be very careful with quoting and sentence structure and often forces annoying redundancy to try to avoid such problems. * Users stumble over pronunciation ("am" as in "I am a person not a backend" or "am" as in "the first and thirteenth letters in the alphabet in order are "A-M"); this may drive confusion when one user tries to explain to another what they are doing. * While "am" is the tool driving this backend, the tool driving git-am is git-apply, and since we are driving towards lower-level tools for the naming of the merge backend we may as well do so here too. * The directory where state is stored has never been called .git/rebase-am, it was always called .git/rebase-apply. For all the reasons listed above: * Modify the documentation to refer to the backends with the new names * Provide a brief note in the documentation connecting the new names to the old names in case users run across the old names anywhere (e.g. in old release notes or older versions of the documentation) * Change the (new) --am command line flag to --apply * Rename some enums, variables, and functions to reinforce the new backend names for us as well. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-15 21:36:41 +00:00
test_run_rebase success 'd n o e' --apply
rebase: define linearization ordering and enforce it Ever since commit 3f213981e44a ("add tests for rebasing merged history", 2013-06-06), t3425 has had tests which included the rebasing of merged history and whose order of applied commits was checked. Unfortunately, the tests expected different behavior depending on which backend was in use. Implementing these checks was the following four lines (including the TODO message) which were repeated verbatim three times in t3425: #TODO: make order consistent across all flavors of rebase test_run_rebase success 'e n o' '' test_run_rebase success 'e n o' -m test_run_rebase success 'n o e' -i As part of the effort to reduce differences between the rebase backends so that users get more uniform behavior, let's define the correct behavior and modify the different backends so they all get the right answer. It turns out that the difference in behavior here is entirely due to topological sorting; since some backends require topological sorting (particularly when --rebase-merges is specified), require it for all modes. Modify the am and merge backends to implement this. Performance Considerations: I was unable to measure any appreciable performance difference with this change. Trying to control the run-to-run variation was difficult; I eventually found a headless beefy box that I could ssh into, which seemed to help. Using git.git, I ran the following testcase: $ git reset --hard v2.20.0-rc1~2 $ time git rebase --quiet v2.20.0-rc0~16 I first ran once to warm any disk caches, then ran five subsequent runs and recorded the times of those five. I observed the following results for the average time: Before this change: "real" timing: 1.340s (standard deviation: 0.040s) "user" timing: 1.050s (standard deviation: 0.041s) "sys" timing: 0.270s (standard deviation: 0.011s) After this change: "real" timing: 1.327s (standard deviation: 0.065s) "user" timing: 1.031s (standard deviation: 0.061s) "sys" timing: 0.280s (standard deviation: 0.014s) Measurements aside, I would expect the timing for walking revisions to be dwarfed by the work involved in creating and applying patches, so this isn't too surprising. Further, while somewhat counter-intuitive, it is possible that turning on topological sorting is actually a performance improvement: by way of comparison, turning on --topo-order made fast-export faster (see https://public-inbox.org/git/20090211135640.GA19600@coredump.intra.peff.net/). Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-11 16:11:38 +00:00
test_run_rebase success 'd n o e' -m
test_run_rebase success 'd n o e' -i
if ! test_have_prereq REBASE_P; then
skip_all='skipping git rebase -p tests, as asked for'
test_done
fi
test_expect_success "rebase -p is no-op in non-linear history" "
reset_rebase &&
git rebase -p d w &&
test_cmp_rev w HEAD
"
test_expect_success "rebase -p is no-op when base inside second parent" "
reset_rebase &&
git rebase -p e w &&
test_cmp_rev w HEAD
"
test_expect_failure "rebase -p --root on non-linear history is a no-op" "
reset_rebase &&
git rebase -p --root w &&
test_cmp_rev w HEAD
"
test_expect_success "rebase -p re-creates merge from side branch" "
reset_rebase &&
git rebase -p z w &&
test_cmp_rev z HEAD^ &&
test_cmp_rev w^2 HEAD^2
"
test_expect_success "rebase -p re-creates internal merge" "
reset_rebase &&
git rebase -p c w &&
test_cmp_rev c HEAD~4 &&
test_cmp_rev HEAD^2^ HEAD~3 &&
test_revision_subjects 'd n e o w' HEAD~3 HEAD~2 HEAD^2 HEAD^ HEAD
"
test_expect_success "rebase -p can re-create two branches on onto" "
reset_rebase &&
git rebase -p --onto c d w &&
test_cmp_rev c HEAD~3 &&
test_cmp_rev c HEAD^2^ &&
test_revision_subjects 'n e o w' HEAD~2 HEAD^2 HEAD^ HEAD
"
# f
# /
# a---b---c---g---h
# \
# d---gp--i
# \ \
# e-------u
#
# gp = cherry-picked g
# h = reverted g
test_expect_success 'setup of non-linear-history for patch-equivalence tests' '
git checkout e &&
test_merge u i
'
test_expect_success "rebase -p re-creates history around dropped commit matching upstream" "
reset_rebase &&
git rebase -p h u &&
test_cmp_rev h HEAD~3 &&
test_cmp_rev HEAD^2^ HEAD~2 &&
test_revision_subjects 'd i e u' HEAD~2 HEAD^2 HEAD^ HEAD
"
test_expect_success "rebase -p --onto in merged history drops patches in upstream" "
reset_rebase &&
git rebase -p --onto f h u &&
test_cmp_rev f HEAD~3 &&
test_cmp_rev HEAD^2^ HEAD~2 &&
test_revision_subjects 'd i e u' HEAD~2 HEAD^2 HEAD^ HEAD
"
test_expect_success "rebase -p --onto in merged history does not drop patches in onto" "
reset_rebase &&
git rebase -p --onto h f u &&
test_cmp_rev h HEAD~3 &&
test_cmp_rev HEAD^2~2 HEAD~2 &&
test_revision_subjects 'd gp i e u' HEAD~2 HEAD^2^ HEAD^2 HEAD^ HEAD
"
# a---b---c---g---h
# \
# d---gp--s
# \ \ /
# \ X
# \ / \
# e---t
#
# gp = cherry-picked g
# h = reverted g
test_expect_success 'setup of non-linear-history for dropping whole side' '
git checkout gp &&
test_merge s e &&
git checkout e &&
test_merge t gp
'
test_expect_failure "rebase -p drops merge commit when entire first-parent side is dropped" "
reset_rebase &&
git rebase -p h s &&
test_cmp_rev h HEAD~2 &&
test_linear_range 'd e' h..
"
test_expect_success "rebase -p drops merge commit when entire second-parent side is dropped" "
reset_rebase &&
git rebase -p h t &&
test_cmp_rev h HEAD~2 &&
test_linear_range 'd e' h..
"
# a---b---c
# \
# d---e
# \ \
# n---r
# \
# o
#
# r = tree-same with n
test_expect_success 'setup of non-linear-history for empty commits' '
git checkout n &&
git merge --no-commit e &&
git reset n . &&
git commit -m r &&
git reset --hard &&
git clean -f &&
git tag r
'
test_expect_success "rebase -p re-creates empty internal merge commit" "
reset_rebase &&
git rebase -p c r &&
test_cmp_rev c HEAD~3 &&
test_cmp_rev HEAD^2^ HEAD~2 &&
test_revision_subjects 'd e n r' HEAD~2 HEAD^2 HEAD^ HEAD
"
test_expect_success "rebase -p re-creates empty merge commit" "
reset_rebase &&
git rebase -p o r &&
test_cmp_rev e HEAD^2 &&
test_cmp_rev o HEAD^ &&
test_revision_subjects 'r' HEAD
"
test_done