Adds git history squash <revision-range> to fold a range of commits.
Changes in v5:
* The range walk now uses --ancestry-path, so only commits descended from
the base are folded; a single revision such as HEAD or HEAD~1 is now
rejected as "not a <base>..<tip> range" rather than treated as a squash
down to the root.
* This adopts the --ancestry-path suggestion; the multi-base rejection is
unchanged, so a side branch that forked before the base and merged in is
still refused.
* Added tests covering more merge topologies: two interior merges, a nested
merge, an octopus merge, an octopus arm forked before the base, a merge
among the descendants replayed above the range, and a ref pointing at an
interior merge commit.
Changes in v4:
* git history squash now detects when another ref points at a commit inside
the range being folded and refuses, with an advice.historyUpdateRefs hint
to use --update-refs=head.
* A merge inside the range is folded fine as long as the range has a single
base; a range with merge commit at the tip or base also folds correctly.
Only a range with more than one base is rejected.
Changes in v3:
* Moved the feature out of git rebase and into a new git history squash
<revision-range> subcommand, per the list discussion. git rebase --squash
is dropped.
* Takes an arbitrary range (git history squash @~3.., git history squash
@~5..@~2), folding it into the oldest commit and replaying any
descendants on top.
* Implemented as a single tree operation rather than picking each commit,
so there are no repeated conflict stops (addresses Phillip's efficiency
point).
* A merge inside the range is folded fine, only a range with more than one
base is rejected.
* --reedit-message seeds the editor with every folded-in message, not just
the oldest.
Harald Nordgren (4):
history: extract helper for a commit's parent tree
history: give commit_tree_ext a message template
history: add squash subcommand to fold a range
history: re-edit a squash with every message
Documentation/config/advice.adoc | 4 +
Documentation/git-history.adoc | 26 ++
advice.c | 1 +
advice.h | 1 +
builtin/history.c | 341 ++++++++++++++++++---
t/meson.build | 1 +
t/t3455-history-squash.sh | 497 +++++++++++++++++++++++++++++++
7 files changed, 833 insertions(+), 38 deletions(-)
create mode 100755 t/t3455-history-squash.sh
base-commit: 26d8d94e94df5535eecd036f16627493506a0614
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2337%2FHaraldNordgren%2Frebase-fixup-fold-v5
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2337/HaraldNordgren/rebase-fixup-fold-v5
Pull-Request: https://github.com/git/git/pull/2337
Range-diff vs v4:
1: fc2801c0b1 = 1: 0f1ae9b05a history: extract helper for a commit's parent tree
2: ee591e83b4 = 2: a97ffab1e6 history: give commit_tree_ext a message template
3: 80bfea642e ! 3: 04e18ef979 history: add squash subcommand to fold a range
@@ builtin/history.c: out:
+ struct rev_info revs;
+ struct commit *commit, *base = NULL, *oldest = NULL, *tip = NULL;
+ struct strvec args = STRVEC_INIT;
++ size_t i;
+ int ret;
+
+ repo_init_revisions(repo, &revs, NULL);
@@ builtin/history.c: out:
+ strvec_push(&args, "--reverse");
+ strvec_push(&args, "--topo-order");
+ strvec_push(&args, "--boundary");
++ strvec_push(&args, "--ancestry-path");
+ strvec_push(&args, range);
+ setup_revisions_from_strvec(&args, &revs, NULL);
+ if (args.nr != 1) {
@@ builtin/history.c: out:
+ goto out;
+ }
+
++ /*
++ * A squash needs a base to reparent onto, so the argument has to
++ * exclude something, as in "<base>..<tip>". A single revision has no
++ * such bottom commit and cannot be squashed.
++ */
++ for (i = 0; i < revs.cmdline.nr; i++)
++ if (revs.cmdline.rev[i].flags & UNINTERESTING)
++ break;
++ if (i == revs.cmdline.nr) {
++ ret = error(_("'%s' is not a '<base>..<tip>' range"), range);
++ goto out;
++ }
++
+ if (prepare_revision_walk(&revs) < 0) {
+ ret = error(_("error preparing revisions"));
+ goto out;
@@ builtin/history.c: out:
+ goto out;
+ }
+
-+ if (!base) {
-+ ret = error(_("cannot squash the root commit"));
-+ goto out;
-+ }
++ if (!base)
++ BUG("a non-empty range must have a boundary commit");
+
+ *base_out = base;
+ *oldest_out = oldest;
@@ t/t3455-history-squash.sh (new)
+ test_grep "the range .* is empty" err
+'
+
-+test_expect_success 'errors when the range includes the root commit' '
++test_expect_success 'errors on a single revision that is not a range' '
+ test_must_fail git history squash HEAD 2>err &&
-+ test_grep "cannot squash the root commit" err
++ test_grep "is not a .*range" err &&
++ test_must_fail git history squash HEAD~1 2>err &&
++ test_grep "is not a .*range" err
+'
+
+test_expect_success 'squashes a range into a single commit without changing the tree' '
@@ t/t3455-history-squash.sh (new)
+ test_path_is_file inner
+'
+
++test_expect_success 'folds a merge of a branch that forked at the base' '
++ git reset --hard start &&
++ git checkout -b base-fork-side &&
++ test_commit --no-tag base-fork-side side x &&
++ git checkout - &&
++ test_commit --no-tag base-fork-main file b &&
++ git merge --no-ff -m "merge base-fork-side" base-fork-side &&
++ git branch -D base-fork-side &&
++ test_commit --no-tag base-fork-tail file c &&
++ tip_tree=$(git rev-parse HEAD^{tree}) &&
++
++ git history squash start.. &&
++
++ git rev-list --count start..HEAD >count &&
++ echo 1 >expect &&
++ test_cmp expect count &&
++ test_cmp_rev start HEAD^ &&
++ test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
++ test_path_is_file side
++'
++
+test_expect_success 'folds a range whose tip is a merge commit' '
+ git reset --hard start &&
+ test_commit --no-tag tipmerge-base file b &&
@@ t/t3455-history-squash.sh (new)
+ test_cmp_rev "$merged" HEAD
+'
+
++test_expect_success 'folds a range with two interior merges' '
++ git reset --hard start &&
++ test_commit --no-tag two-merge-a file a1 &&
++ git checkout -b two-merge-s1 &&
++ test_commit --no-tag two-merge-s1 s1 x &&
++ git checkout - &&
++ git merge --no-ff -m "merge s1" two-merge-s1 &&
++ test_commit --no-tag two-merge-b file b1 &&
++ git checkout -b two-merge-s2 &&
++ test_commit --no-tag two-merge-s2 s2 y &&
++ git checkout - &&
++ git merge --no-ff -m "merge s2" two-merge-s2 &&
++ git branch -D two-merge-s1 two-merge-s2 &&
++ tip_tree=$(git rev-parse HEAD^{tree}) &&
++
++ git history squash start.. &&
++
++ git rev-list --count start..HEAD >count &&
++ echo 1 >expect &&
++ test_cmp expect count &&
++ test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
++ test_path_is_file s1 &&
++ test_path_is_file s2
++'
++
++test_expect_success 'folds a range with a nested merge' '
++ git reset --hard start &&
++ main=$(git symbolic-ref --short HEAD) &&
++ git checkout -b nested-outer &&
++ test_commit --no-tag nested-outer outer x &&
++ git checkout -b nested-inner &&
++ test_commit --no-tag nested-inner inner y &&
++ git checkout nested-outer &&
++ git merge --no-ff -m "merge inner" nested-inner &&
++ git checkout "$main" &&
++ test_commit --no-tag nested-main file b1 &&
++ git merge --no-ff -m "merge outer" nested-outer &&
++ git branch -D nested-outer nested-inner &&
++ tip_tree=$(git rev-parse HEAD^{tree}) &&
++
++ git history squash start.. &&
++
++ git rev-list --count start..HEAD >count &&
++ echo 1 >expect &&
++ test_cmp expect count &&
++ test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
++ test_path_is_file outer &&
++ test_path_is_file inner
++'
++
++test_expect_success 'folds a range with an octopus merge' '
++ git reset --hard start &&
++ main=$(git symbolic-ref --short HEAD) &&
++ test_commit --no-tag octo-base file a1 &&
++ git checkout -b octo-1 &&
++ test_commit --no-tag octo-1 o1 x &&
++ git checkout "$main" &&
++ git checkout -b octo-2 &&
++ test_commit --no-tag octo-2 o2 y &&
++ git checkout "$main" &&
++ git merge --no-ff -m octopus octo-1 octo-2 &&
++ git branch -D octo-1 octo-2 &&
++ tip_tree=$(git rev-parse HEAD^{tree}) &&
++
++ git history squash start.. &&
++
++ git rev-list --count start..HEAD >count &&
++ echo 1 >expect &&
++ test_cmp expect count &&
++ test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
++ test_path_is_file o1 &&
++ test_path_is_file o2
++'
++
++test_expect_success 'refuses an octopus merge with an arm forked before the base' '
++ git reset --hard start &&
++ main=$(git symbolic-ref --short HEAD) &&
++ git checkout -b octo-pre &&
++ test_commit octo-pre-side pside x &&
++ git checkout "$main" &&
++ test_commit octo-pre-main file b1 &&
++ octo_base=$(git rev-parse HEAD) &&
++ git checkout -b octo-within &&
++ test_commit --no-tag octo-within wside y &&
++ git checkout "$main" &&
++ git merge --no-ff -m octopus octo-pre octo-within &&
++ merged=$(git rev-parse HEAD) &&
++ git branch -D octo-pre octo-within &&
++
++ test_must_fail git history squash "$octo_base.." 2>err &&
++ test_grep "more than one base" err &&
++ test_cmp_rev "$merged" HEAD
++'
++
++test_expect_success 'refuses when a descendant above the range is a merge' '
++ git reset --hard start &&
++ main=$(git symbolic-ref --short HEAD) &&
++ test_commit --no-tag desc-base file b &&
++ git tag desc-tip &&
++ git checkout -b desc-above &&
++ test_commit --no-tag desc-above above x &&
++ git checkout "$main" &&
++ test_commit --no-tag desc-main file c &&
++ git merge --no-ff -m "merge desc-above" desc-above &&
++ git branch -D desc-above &&
++ head_before=$(git rev-parse HEAD) &&
++
++ test_must_fail git history squash start..desc-tip 2>err &&
++ test_grep "merge commits is not supported" err &&
++ test_cmp_rev "$head_before" HEAD
++'
++
++test_expect_success 'refuses to fold a range a ref points into at a merge' '
++ git reset --hard start &&
++ main=$(git symbolic-ref --short HEAD) &&
++ test_commit --no-tag refmerge-base file b &&
++ git checkout -b refmerge-side &&
++ test_commit --no-tag refmerge-side side x &&
++ git checkout "$main" &&
++ test_commit --no-tag refmerge-main file c &&
++ git merge --no-ff -m "interior merge" refmerge-side &&
++ git branch -D refmerge-side &&
++ git branch at-merge HEAD &&
++ test_commit --no-tag refmerge-tail file d &&
++ head_before=$(git rev-parse HEAD) &&
++
++ test_must_fail git history squash start.. 2>err &&
++ test_grep "at-merge" err &&
++ test_grep "points into the squashed range" err &&
++ test_cmp_rev "$head_before" HEAD &&
++
++ git branch -D at-merge
++'
++
+test_done
4: 85c7817d7e = 4: a758e1f084 history: re-edit a squash with every messageHarald Nordgren via GitGitGadget <gitgitgadget@gmail.com>