cherry-pick: refuse cherry-pick sequence if index is dirty
PATCH 1/1 cherry-pick: refuse cherry-pick sequence if index is dirty
From: Tao Klerks <[email protected]>
Cherry-pick, like merge or rebase, refuses to run when there are changes in the index. However, if a cherry-pick sequence is requested, this refusal happens "too late": when the cherry-pick sequence has already started, and an "--abort" or "--quit" is needed to resume normal operation.
Normally, when an operation is "in-progress" and you want to go back to where you were before, "--abort" is the right thing to run. If you run "git cherry-pick --abort" in this specific situation, however, your staged changes are destroyed as part of the abort! Generally speaking, the abort process assumes any changes in the index are part of the operation to be aborted.
Add an earlier check in the cherry-pick sequence process to ensure that the index is clean, reusing the already-generalized method used for rebase. Also add a test.
---
cherry-pick: refuse cherry-pick sequence if index is dirty
I encountered this data-loss bug (performing normally-safe operations results in loss of local staged changes) while exploring largely-unrelated changes as per thread CAPMMpogFHnX2YPA4VmffmA0pku=43CQJ8iebCOkFm4ravBVTeg@mail.gmail.com on "git checkout --force", and on the possibility of supporting same-commit switch while preserving merge metadata.
I believe it is best handled as a standalone issue, it looks like a simple bugfix to me, hence this separate patch.
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1535%2FTaoK%2Ftao-cherry-pick-sequence-safety-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1535/TaoK/tao-cherry-pick-sequence-safety-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1535
builtin/revert.c | 2 +- sequencer.c | 14 +++++++++----- sequencer.h | 3 ++- t/t3510-cherry-pick-sequence.sh | 10 ++++++++++ 4 files changed, 22 insertions(+), 7 deletions(-)
builtin/revert.c +1 -1
@@ -224,7 +224,7 @@ static int run_sequencer(int argc, const char **argv, const char *prefix,return sequencer_rollback (the_repository, opts);if (cmd =='s' )return sequencer_skip (the_repository, opts); -return sequencer_pick_revisions (the_repository, opts); +return sequencer_pick_revisions (the_repository, opts, me); }int cmd_revert (int argc,const char **argv,const char *prefix)
sequencer.c +9 -5
@@ -3162,7 +3162,7 @@ static int walk_revs_populate_todo(struct todo_list *todo_list,return 0 ; } -static int create_seq_dir (struct repository *r) +static int create_seq_dir (struct repository *r,const char *requested_action) {enum replay_action action;const char *in_progress_error =NULL ;
@@ -3194,6 +3194,9 @@ static int create_seq_dir(struct repository *r) advise_skip ? "--skip | " : "");return -1 ; } +if (require_clean_work_tree (r, requested_action, +_ ("Please commit or stash them." ),1 ,1 )) +return -1 ;if (mkdir (git_path_seq_dir (),0777 ) <0 )return error_errno (_ ("could not create sequencer directory '%s'" ),git_path_seq_dir ());
@@ -5169,7 +5172,8 @@ static int single_pick(struct repository *r, }int sequencer_pick_revisions (struct repository *r, -struct replay_opts *opts) +struct replay_opts *opts, +const char *action) {struct todo_list todo_list =TODO_LIST_INIT ;struct object_id oid;
@@ -5223,12 +5227,12 @@ int sequencer_pick_revisions(struct repository *r,/* * Start a new cherry-pick/ revert sequence; but -* first, make sure that an existing one isn't in -* progress +* first, make sure that the index is clean and that +* an existing one isn't in progress. */ if (walk_revs_populate_todo (&todo_list, opts) || -create_seq_dir (r) <0 ) +create_seq_dir (r, action) <0 )return -1 ;if (repo_get_oid (r,"HEAD" , &oid) && (opts->action ==REPLAY_REVERT ))return error (_ ("can't revert as initial commit" ));
sequencer.h +2 -1
@@ -159,7 +159,8 @@ void todo_list_filter_update_refs(struct repository *r,/* Call this to setup defaults before parsing command line options */ void sequencer_init_config (struct replay_opts *opts);int sequencer_pick_revisions (struct repository *repo, -struct replay_opts *opts); +struct replay_opts *opts, +const char *action);int sequencer_continue (struct repository *repo,struct replay_opts *opts);int sequencer_rollback (struct repository *repo,struct replay_opts *opts);int sequencer_skip (struct repository *repo,struct replay_opts *opts);
t/t3510-cherry-pick-sequence.sh +10 -0
@@ -47,6 +47,16 @@ test_expect_success 'cherry-pick persists data on failure' ' test_path_is_file .git/sequencer/opts ' +test_expect_success 'cherry-pick sequence refuses to run on dirty index' ' + pristine_detach initial && + touch localindexchange && + git add localindexchange && + echo picking && + test_must_fail git cherry-pick initial..picked && + test_path_is_missing .git/sequencer && + test_must_fail git cherry-pick --abort +' + test_expect_success 'cherry-pick mid-cherry-pick-sequence' ' pristine_detach initial && test_must_fail git cherry-pick base..anotherpick &&
base-commit: 4a714b37029a4b63dbd22f7d7ed81f7a0d693680
Signature · 1 line
gitgitgadget
Quoted 16 lines · Tao Klerks via GitGitGadget
From: Tao Klerks <[email protected]>
Cherry-pick, like merge or rebase, refuses to run when there are changes in the index. However, if a cherry-pick sequence is requested, this refusal happens "too late": when the cherry-pick sequence has already started, and an "--abort" or "--quit" is needed to resume normal operation.
Normally, when an operation is "in-progress" and you want to go back to where you were before, "--abort" is the right thing to run. If you run "git cherry-pick --abort" in this specific situation, however, your staged changes are destroyed as part of the abort! Generally speaking, the abort process assumes any changes in the index are part of the operation to be aborted.
Quoted 6 lines
Add an earlier check in the cherry-pick sequence process to ensure that the index is clean, reusing the already-generalized method used for rebase. Also add a test.
Signed-off-by Tao Klerks <[email protected]>---
My apologies for the premature submission: I've now realized I used the wrong existing check. "git rebase" checks for a clean *worktree* (ignoring untracked files), and that is what I reused here. What git merge and git cherry-pick check for, and what I should have added a check for here, is a clean *index*.
The current implementation of this patch is far too restrictive. It doesn't break any tests (and maybe I should add one now that I know), but it's doing the wrong thing.
Tao
Quoted 3 lines · Tao Klerks
The current implementation of this patch is far too restrictive. It doesn't break any tests (and maybe I should add one now that I know), but it's doing the wrong thing.
I am ambivalent. What do we want to see in a multi-pick sequence that is different from rebase? A single-step cherry-pick can fail safely before it touches the index or the working tree files, but if two-step cherry-pick, whose first step succeeds, finds that it cannot safely carry out its second step without clobbering the local changes made to the working tree files, what should happen? Are we OK if we stopped in the state just after the first step has already been done?
My (tentative) answer to that question is "yes", but the recovery options of "cherry-pick" may want to work differently from what we have seen them traditionally do. Namely, the user accepts that the first step is already done, and stopping "cherry-pick", be it called "--abort" or something else, should just remove the sequencer state and behave as if the single-pick cherry-pick on the first step only has just finished and leave such a state in the index and the working tree. If that is what we are going to do, then it would make sense to adopt the same safety semantics we use for "git merge" and "git checkout" to ensure only that the index is clean, relying on the unpack-trees machinery that stops before clobbering a locally modified working tree files. But if we are to aim for "all-or-none" semantics people expect from aborting "git rebase", I suspect that it would be way too complicated to allow random changes in the working tree files that we may only discover to be problems after starting the sequence of replaying commits one-by-one, and "too restrictive" check may be justified. To put it differently, if it is too restrictive for multi-pick, then we would want to loosen it for "git rebase" as well, as the issues are likely to be the same.
Thanks.
Quoted 9 lines · Junio C Hamano
Quoted 3 lines · Tao Klerks
The current implementation of this patch is far too restrictive. It doesn't break any tests (and maybe I should add one now that I know), but it's doing the wrong thing.
I am ambivalent. What do we want to see in a multi-pick sequence that is different from rebase?
I would argue there are primarily three things that are different:
1. The checkout of the new base (and checkout of the original in an "--abort")
2. The support for and/or more-common expectation of "messing" with commits as you go, eg squash, edit
3. The (partial) support for rebasing/recreating merge commits
I'm not sure to what extent any of these justify having tighter restrictions on when we allow a rebase to start, though.
Quoted 7 lines
A single-step cherry-pick can fail
safely before it touches the index or the working tree files, but if two-step cherry-pick, whose first step succeeds, finds that it cannot safely carry out its second step without clobbering the local changes made to the working tree files, what should happen? Are we OK if we stopped in the state just after the first step has already been done?
This is the current behavior: it stops before the specific pick that is going to affect local unstaged changes, or if there are *any* staged changes (in which case it stops as it's about to do the first pick - the first time this check runs). The reasoning for this behavior, as I understand it, is that the "--abort" strategy, intending to "undo whatever I started doing here, including a conflict resolution", resets the index. So as long as there is nothing you want to keep in the index, and as long as we know that any previous picks haven't impacted any files with unstaged changes, we're good.
The bug that I want to fix is that we only end up checking whether there are changes in the index *after* we've already committed to resetting the index upon later "--abort". It's a kind of catch-22:
we've detected that aborting would destroy your work, so we leave you in a state where the most obvious thing to do is abort, so we destroy your work... Of course, if you understand what's going on you can choose to "--quit" and *not* lose your work... but this is completely antithetical to the general intent of "--abort".
There's another, smaller flaw here I think, common to Merge, Single-Cherry-Pick, and Sequence-Cherry-Pick, which is that *if* you start with unstaged changes, and you end up in a conflict resolution or "--no-commit" pause, and you then "git add" your unstaged changes during that pause/resolution, and you *then* later "--abort"... then your originally-unstaged changes are destroyed by the "--abort" - so it has *not* taken you back to where you were before the operation started. This is, to me as a user, non-obvious, and could potentially lead to data loss. The only way I see to fix that, is to have *all* of these operations refuse to operate on dirty worktrees altogether - like rebase already does.
I suspect this level of "strictness" would be welcome to newcomers, and less welcome to existing experienced users.
Quoted 9 lines
My (tentative) answer to that question is "yes", but the recovery options of "cherry-pick" may want to work differently from what we have seen them traditionally do. Namely, the user accepts that the first step is already done, and stopping "cherry-pick", be it called "--abort" or something else, should just remove the sequencer state and behave as if the single-pick cherry-pick on the first step only has just finished and leave such a state in the index and the working tree.
This behavior exists, and is called "--quit", right?
The semantics as I understand it are:
--quit: I know what I'm doing, just remove any "ongoing operation" metadata and let me work with the current index and worktree. --abort: This was a bad idea, please take me back to where I was before I started this operation (without losing any work I had ongoing, pls!)
Quoted 5 lines
If that is what we are going to do, then it would
make sense to adopt the same safety semantics we use for "git merge" and "git checkout" to ensure only that the index is clean, relying on the unpack-trees machinery that stops before clobbering a locally modified working tree files.
Yep
Quoted 6 lines
But if we are to aim for "all-or-none"
semantics people expect from aborting "git rebase", I suspect that it would be way too complicated to allow random changes in the working tree files that we may only discover to be problems after starting the sequence of replaying commits one-by-one, and "too restrictive" check may be justified.
I don't think I understand this argument. If we want to support both sets of semantics, then that's exactly what "--quit" and "--abort" achieve, right? (as long as we check for the dirty index *before* committing to destroying the index in case of "--abort")
Quoted 3 lines
To put it differently, if it
is too restrictive for multi-pick, then we would want to loosen it for "git rebase" as well, as the issues are likely to be the same.
My argument for only changing "sequence-cherry-pick" here, and having it (continue to) use the index-safety-only semantics of single-cherry-pick and merge, is that *this is not a change in cabability* - it is only a bugfix. Switching to the worktree-safety semantics of rebase would be a substantial change in behavior beyond the bugfix.
I, personally, would prefer to see the worktree-safety semantics of rebase be used in *all* these operations, so I could no longer shoot myself in the foot by starting a merge, accidentally staging some previously-unstaged changes during conflict resolution, and then losing those changes by "--abort"ing. But I expect that this kind of change would need to be behind a config option of some sort, trading off safety against low friction.
I could imagine a setting like "core.OperationWorktreeSafety", with settings "default" (current behavior - rebase disallows dirty worktrees, the others disallow dirty index), "strict" (all behave like current rebase) and "lax" (all behave like merge).
As discussed elsewhere, I would also like to (have an option to) treat untracked files as "worktree dirtiness"/unstaged changes in exactly the same way as changes to tracked files - but that's another topic :)
I'll prepare a v2 with index-safety-only for sequence-cherry-pick for now, please let me know if a (better-named) "core.OperationWorktreeSafety" option is something that you'd be interested in / that would make sense to you.
Thanks!
PATCH v2 1/1 cherry-pick: refuse cherry-pick sequence if index is dirty
In reply to Tao Klerks via GitGitGadgetFrom: Tao Klerks <[email protected]>
Cherry-pick, like merge or rebase, refuses to run when there are changes in the index. However, if a cherry-pick sequence is requested, this refusal happens "too late": when the cherry-pick sequence has already started, and an "--abort" or "--quit" is needed to resume normal operation.
Normally, when an operation is "in-progress" and you want to go back to where you were before, "--abort" is the right thing to run. If you run "git cherry-pick --abort" in this specific situation, however, your staged changes are destroyed as part of the abort! Generally speaking, the abort process assumes any changes in the index are part of the operation to be aborted.
Add an earlier check in the cherry-pick sequence process to ensure that the index is clean, introducing a new general "quit if index dirty" function derived from the existing worktree-level function used in rebase and pull. Also add a test.
---
cherry-pick: refuse cherry-pick sequence if index is dirty
V2: In the first version I had reused the require_clean_work_tree() function, which meant I accidentally tightened the requirements for sequence cherry-pick, from "no staged changes" to "no staged or uncommitted changes".
I've now introduced a new function require_clean_index() reusing the existing code.
In the thread, Junio suggested it might make sense to make the requirements for sequence-cherry-pick the same as rebase - either to tighten them as I accidentally did before, or relax rebase to match the existing behavior of merge and cherry-pick. I am not sure the right way to make such changes would be, I think it might warrant a new configuration option, but I definitely think it is beyond the scope of this simple bugfix.
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1535%2FTaoK%2Ftao-cherry-pick-sequence-safety-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1535/TaoK/tao-cherry-pick-sequence-safety-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/1535
Range-diff vs v1:
1: ed225309835 ! 1: be9a592a34a cherry-pick: refuse cherry-pick sequence if index is dirty
@@ Commit message
operation to be aborted.
Add an earlier check in the cherry-pick sequence process to ensure that
- the index is clean, reusing the already-generalized method used for
- rebase. Also add a test.
+ the index is clean, introducing a new general "quit if index dirty" function
+ derived from the existing worktree-level function used in rebase and pull.
+ Also add a test.
Signed-off-by: Tao Klerks <[email protected]>
- ## builtin/revert.c ##
-@@ builtin/revert.c: static int run_sequencer(int argc, const char **argv, const char *prefix,
- return sequencer_rollback(the_repository, opts);
- if (cmd == 's')
- return sequencer_skip(the_repository, opts);
-- return sequencer_pick_revisions(the_repository, opts);
-+ return sequencer_pick_revisions(the_repository, opts, me);
- }
-
- int cmd_revert(int argc, const char **argv, const char *prefix)
-
## sequencer.c ##
@@ sequencer.c: static int walk_revs_populate_todo(struct todo_list *todo_list,
return 0;
}
-static int create_seq_dir(struct repository *r)
-+static int create_seq_dir(struct repository *r, const char *requested_action)
++static const char *cherry_pick_action_name(enum replay_action action) {
++ switch (action) {
++ case REPLAY_REVERT:
++ return "revert";
++ break;
++ case REPLAY_PICK:
++ return "cherry-pick";
++ break;
++ default:
++ BUG("unexpected action in cherry_pick_action_name");
++ }
++}
++
++static int create_seq_dir(struct repository *r, enum replay_action requested_action)
{
- enum replay_action action;
+- enum replay_action action;
++ enum replay_action in_progress_action;
++ const char *in_progress_action_name = NULL;
const char *in_progress_error = NULL;
-@@ sequencer.c: static int create_seq_dir(struct repository *r)
+ const char *in_progress_advice = NULL;
++ const char *requested_action_name = NULL;
+ unsigned int advise_skip =
+ refs_ref_exists(get_main_ref_store(r), "REVERT_HEAD") ||
+ refs_ref_exists(get_main_ref_store(r), "CHERRY_PICK_HEAD");
+
+- if (!sequencer_get_last_command(r, &action)) {
+- switch (action) {
+- case REPLAY_REVERT:
+- in_progress_error = _("revert is already in progress");
+- in_progress_advice =
+- _("try \"git revert (--continue | %s--abort | --quit)\"");
+- break;
+- case REPLAY_PICK:
+- in_progress_error = _("cherry-pick is already in progress");
+- in_progress_advice =
+- _("try \"git cherry-pick (--continue | %s--abort | --quit)\"");
+- break;
+- default:
+- BUG("unexpected action in create_seq_dir");
+- }
++ if (!sequencer_get_last_command(r, &in_progress_action)) {
++ in_progress_action_name = cherry_pick_action_name(in_progress_action);
++ in_progress_error = _("%s is already in progress");
++ in_progress_advice =
++ _("try \"git %s (--continue | %s--abort | --quit)\"");
+ }
+ if (in_progress_error) {
+- error("%s", in_progress_error);
++ error(in_progress_error, in_progress_action_name);
+ if (advice_enabled(ADVICE_SEQUENCER_IN_USE))
+ advise(in_progress_advice,
++ in_progress_action_name,
advise_skip ? "--skip | " : "");
return -1;
}
-+ if (require_clean_work_tree(r, requested_action,
++ requested_action_name = cherry_pick_action_name(requested_action);
++ if (require_clean_index(r, requested_action_name,
+ _("Please commit or stash them."), 1, 1))
+ return -1;
if (mkdir(git_path_seq_dir(), 0777) < 0)
return error_errno(_("could not create sequencer directory '%s'"),
git_path_seq_dir());
-@@ sequencer.c: static int single_pick(struct repository *r,
- }
-
- int sequencer_pick_revisions(struct repository *r,
-- struct replay_opts *opts)
-+ struct replay_opts *opts,
-+ const char *action)
- {
- struct todo_list todo_list = TODO_LIST_INIT;
- struct object_id oid;
@@ sequencer.c: int sequencer_pick_revisions(struct repository *r,
/*
@@ sequencer.c: int sequencer_pick_revisions(struct repository *r,
+ * first, make sure that the index is clean and that
+ * an existing one isn't in progress.
*/
-
+-
if (walk_revs_populate_todo(&todo_list, opts) ||
- create_seq_dir(r) < 0)
-+ create_seq_dir(r, action) < 0)
++ create_seq_dir(r, opts->action) < 0)
return -1;
if (repo_get_oid(r, "HEAD", &oid) && (opts->action == REPLAY_REVERT))
return error(_("can't revert as initial commit"));
- ## sequencer.h ##
-@@ sequencer.h: void todo_list_filter_update_refs(struct repository *r,
- /* Call this to setup defaults before parsing command line options */
- void sequencer_init_config(struct replay_opts *opts);
- int sequencer_pick_revisions(struct repository *repo,
-- struct replay_opts *opts);
-+ struct replay_opts *opts,
-+ const char *action);
- int sequencer_continue(struct repository *repo, struct replay_opts *opts);
- int sequencer_rollback(struct repository *repo, struct replay_opts *opts);
- int sequencer_skip(struct repository *repo, struct replay_opts *opts);
-
## t/t3510-cherry-pick-sequence.sh ##
@@ t/t3510-cherry-pick-sequence.sh: test_expect_success 'cherry-pick persists data on failure' '
test_path_is_file .git/sequencer/opts
@@ t/t3510-cherry-pick-sequence.sh: test_expect_success 'cherry-pick persists data
test_expect_success 'cherry-pick mid-cherry-pick-sequence' '
pristine_detach initial &&
test_must_fail git cherry-pick base..anotherpick &&
+
+ ## wt-status.c ##
+@@ wt-status.c: int has_uncommitted_changes(struct repository *r,
+ return result;
+ }
+
+-/**
+- * If the work tree has unstaged or uncommitted changes, dies with the
+- * appropriate message.
+- */
+-int require_clean_work_tree(struct repository *r,
+- const char *action,
+- const char *hint,
+- int ignore_submodules,
+- int gently)
++static int require_clean_index_or_work_tree(struct repository *r,
++ const char *action,
++ const char *hint,
++ int ignore_submodules,
++ int check_index_only,
++ int gently)
+ {
+ struct lock_file lock_file = LOCK_INIT;
+ int err = 0, fd;
+@@ wt-status.c: int require_clean_work_tree(struct repository *r,
+ repo_update_index_if_able(r, &lock_file);
+ rollback_lock_file(&lock_file);
+
+- if (has_unstaged_changes(r, ignore_submodules)) {
+- /* TRANSLATORS: the action is e.g. "pull with rebase" */
+- error(_("cannot %s: You have unstaged changes."), _(action));
+- err = 1;
++ if (!check_index_only) {
++ if (has_unstaged_changes(r, ignore_submodules)) {
++ /* TRANSLATORS: the action is e.g. "pull with rebase" */
++ error(_("cannot %s: You have unstaged changes."), _(action));
++ err = 1;
++ }
+ }
+
+ if (has_uncommitted_changes(r, ignore_submodules)) {
+@@ wt-status.c: int require_clean_work_tree(struct repository *r,
+
+ return err;
+ }
++
++/**
++ * If the work tree has unstaged or uncommitted changes, dies with the
++ * appropriate message.
++ */
++int require_clean_work_tree(struct repository *r,
++ const char *action,
++ const char *hint,
++ int ignore_submodules,
++ int gently)
++{
++ return require_clean_index_or_work_tree(r,
++ action,
++ hint,
++ ignore_submodules,
++ 0,
++ gently);
++}
++
++/**
++ * If the work tree has uncommitted changes, dies with the appropriate
++ * message.
++ */
++int require_clean_index(struct repository *r,
++ const char *action,
++ const char *hint,
++ int ignore_submodules,
++ int gently)
++{
++ return require_clean_index_or_work_tree(r,
++ action,
++ hint,
++ ignore_submodules,
++ 1,
++ gently);
++}
+
+ ## wt-status.h ##
+@@ wt-status.h: int require_clean_work_tree(struct repository *repo,
+ const char *hint,
+ int ignore_submodules,
+ int gently);
++int require_clean_index(struct repository *repo,
++ const char *action,
++ const char *hint,
++ int ignore_submodules,
++ int gently);
+
+ #endif /* STATUS_H */sequencer.c | 53 ++++++++++++++++------------ t/t3510-cherry-pick-sequence.sh | 10 ++++++ wt-status.c | 61 ++++++++++++++++++++++++++------- wt-status.h | 5 +++ 4 files changed, 94 insertions(+), 35 deletions(-)
sequencer.c +31 -22
@@ -3162,38 +3162,48 @@ static int walk_revs_populate_todo(struct todo_list *todo_list,return 0 ; } -static int create_seq_dir (struct repository *r) +static const char *cherry_pick_action_name (enum replay_action action) { +switch (action) { +case REPLAY_REVERT : +return "revert" ; +break ; +case REPLAY_PICK : +return "cherry-pick" ; +break ; +default : +BUG ("unexpected action in cherry_pick_action_name" ); + } +} + +static int create_seq_dir (struct repository *r,enum replay_action requested_action) { -enum replay_action action; +enum replay_action in_progress_action; +const char *in_progress_action_name =NULL ;const char *in_progress_error =NULL ;const char *in_progress_advice =NULL ; +const char *requested_action_name =NULL ;unsigned int advise_skip =refs_ref_exists (get_main_ref_store (r),"REVERT_HEAD" ) ||refs_ref_exists (get_main_ref_store (r),"CHERRY_PICK_HEAD" ); -if (!sequencer_get_last_command (r, &action)) { -switch (action) { -case REPLAY_REVERT : - in_progress_error =_ ("revert is already in progress" ); - in_progress_advice = -_ ("try \"git revert (--continue | %s--abort | --quit)\"" ); -break ; -case REPLAY_PICK : - in_progress_error =_ ("cherry-pick is already in progress" ); - in_progress_advice = -_ ("try \"git cherry-pick (--continue | %s--abort | --quit)\"" ); -break ; -default : -BUG ("unexpected action in create_seq_dir" ); - } +if (!sequencer_get_last_command (r, &in_progress_action)) { + in_progress_action_name =cherry_pick_action_name (in_progress_action); + in_progress_error =_ ("%s is already in progress" ); + in_progress_advice = +_ ("try \"git %s (--continue | %s--abort | --quit)\"" ); }if (in_progress_error) { -error ("%s" , in_progress_error); +error (in_progress_error, in_progress_action_name);if (advice_enabled (ADVICE_SEQUENCER_IN_USE ))advise (in_progress_advice, + in_progress_action_name, advise_skip ?"--skip | " :"" );return -1 ; } + requested_action_name =cherry_pick_action_name (requested_action); +if (require_clean_index (r, requested_action_name, +_ ("Please commit or stash them." ),1 ,1 )) +return -1 ;if (mkdir (git_path_seq_dir (),0777 ) <0 )return error_errno (_ ("could not create sequencer directory '%s'" ),git_path_seq_dir ());
@@ -5223,12 +5233,11 @@ int sequencer_pick_revisions(struct repository *r,/* * Start a new cherry-pick/ revert sequence; but -* first, make sure that an existing one isn't in -* progress +* first, make sure that the index is clean and that +* an existing one isn't in progress. */ -if (walk_revs_populate_todo (&todo_list, opts) || -create_seq_dir (r) <0 ) +create_seq_dir (r, opts->action) <0 )return -1 ;if (repo_get_oid (r,"HEAD" , &oid) && (opts->action ==REPLAY_REVERT ))return error (_ ("can't revert as initial commit" ));
t/t3510-cherry-pick-sequence.sh +10 -0
@@ -47,6 +47,16 @@ test_expect_success 'cherry-pick persists data on failure' ' test_path_is_file .git/sequencer/opts ' +test_expect_success 'cherry-pick sequence refuses to run on dirty index' ' + pristine_detach initial && + touch localindexchange && + git add localindexchange && + echo picking && + test_must_fail git cherry-pick initial..picked && + test_path_is_missing .git/sequencer && + test_must_fail git cherry-pick --abort +' + test_expect_success 'cherry-pick mid-cherry-pick-sequence' ' pristine_detach initial && test_must_fail git cherry-pick base..anotherpick &&
wt-status.c +48 -13
76 lines not on this page · raw message
wt-status.h +5 -0
@@ -181,5 +181,10 @@ int require_clean_work_tree(struct repository *repo,const char *hint, int ignore_submodules, int gently); +int require_clean_index (struct repository *repo, +const char *action, +const char *hint, +int ignore_submodules, +int gently);#endif /* STATUS_H */
base-commit: 4a714b37029a4b63dbd22f7d7ed81f7a0d693680
Signature · 1 line
gitgitgadget
Quoted 28 lines · Tao Klerks
Quoted 9 lines · Junio C Hamano
Quoted 3 lines · Tao Klerks
The current implementation of this patch is far too restrictive. It doesn't break any tests (and maybe I should add one now that I know), but it's doing the wrong thing.
I am ambivalent. What do we want to see in a multi-pick sequence that is different from rebase?
I would argue there are primarily three things that are different:
1. The checkout of the new base (and checkout of the original in an "--abort")
2. The support for and/or more-common expectation of "messing" with commits as you go, eg squash, edit
3. The (partial) support for rebasing/recreating merge commitsI'm not sure to what extent any of these justify having tighter restrictions on when we allow a rebase to start, though.
Quoted 7 lines
A single-step cherry-pick can fail
safely before it touches the index or the working tree files, but if two-step cherry-pick, whose first step succeeds, finds that it cannot safely carry out its second step without clobbering the local changes made to the working tree files, what should happen? Are we OK if we stopped in the state just after the first step has already been done?
Quoted 9 lines
This is the current behavior: it stops before the specific pick that is going to affect local unstaged changes, or if there are *any* staged changes (in which case it stops as it's about to do the first pick - the first time this check runs). The reasoning for this behavior, as I understand it, is that the "--abort" strategy, intending to "undo whatever I started doing here, including a conflict resolution", resets the index. So as long as there is nothing you want to keep in the index, and as long as we know that any previous picks haven't impacted any files with unstaged changes, we're good.
"cherry-pick --abort" uses "reset --merge" so is slightly more complicated than just resetting the index.
Quoted 21 lines
The bug that I want to fix is that we only end up checking whether there are changes in the index *after* we've already committed to resetting the index upon later "--abort". It's a kind of catch-22:
we've detected that aborting would destroy your work, so we leave you in a state where the most obvious thing to do is abort, so we destroy your work... Of course, if you understand what's going on you can choose to "--quit" and *not* lose your work... but this is completely antithetical to the general intent of "--abort".There's another, smaller flaw here I think, common to Merge, Single-Cherry-Pick, and Sequence-Cherry-Pick, which is that *if* you start with unstaged changes, and you end up in a conflict resolution or "--no-commit" pause, and you then "git add" your unstaged changes during that pause/resolution, and you *then* later "--abort"... then your originally-unstaged changes are destroyed by the "--abort" - so it has *not* taken you back to where you were before the operation started. This is, to me as a user, non-obvious, and could potentially lead to data loss. The only way I see to fix that, is to have *all* of these operations refuse to operate on dirty worktrees altogether - like rebase already does.
Quoted 2 lines
I suspect this level of "strictness" would be welcome to newcomers, and less welcome to existing experienced users.
Indeed, being able to cherry-pick when the worktree is dirty is occasionally useful but it is confusing when "cherry-pick --abort" does not restore the pre-cherry-pick state (and as Junio says below it would be complicated to preserve the initial changes when aborting).
Quoted 10 lines
Quoted 8 lines
My (tentative) answer to that question is "yes", but the recovery options of "cherry-pick" may want to work differently from what we have seen them traditionally do. Namely, the user accepts that the first step is already done, and stopping "cherry-pick", be it called "--abort" or something else, should just remove the sequencer state and behave as if the single-pick cherry-pick on the first step only has just finished and leave such a state in the index and the working tree.
This behavior exists, and is called "--quit", right?
I think so though I'm not sure what what "--quit" does to CHERRY_PICK_HEAD.
Quoted 51 lines
The semantics as I understand it are:
--quit: I know what I'm doing, just remove any "ongoing operation" metadata and let me work with the current index and worktree. --abort: This was a bad idea, please take me back to where I was before I started this operation (without losing any work I had ongoing, pls!)Quoted 5 lines
If that is what we are going to do, then it would
make sense to adopt the same safety semantics we use for "git merge" and "git checkout" to ensure only that the index is clean, relying on the unpack-trees machinery that stops before clobbering a locally modified working tree files.Yep
Quoted 6 lines
But if we are to aim for "all-or-none"
semantics people expect from aborting "git rebase", I suspect that it would be way too complicated to allow random changes in the working tree files that we may only discover to be problems after starting the sequence of replaying commits one-by-one, and "too restrictive" check may be justified.I don't think I understand this argument. If we want to support both sets of semantics, then that's exactly what "--quit" and "--abort" achieve, right? (as long as we check for the dirty index *before* committing to destroying the index in case of "--abort")
Quoted 3 lines
To put it differently, if it
is too restrictive for multi-pick, then we would want to loosen it for "git rebase" as well, as the issues are likely to be the same.My argument for only changing "sequence-cherry-pick" here, and having it (continue to) use the index-safety-only semantics of single-cherry-pick and merge, is that *this is not a change in cabability* - it is only a bugfix. Switching to the worktree-safety semantics of rebase would be a substantial change in behavior beyond the bugfix.
I, personally, would prefer to see the worktree-safety semantics of rebase be used in *all* these operations, so I could no longer shoot myself in the foot by starting a merge, accidentally staging some previously-unstaged changes during conflict resolution, and then losing those changes by "--abort"ing. But I expect that this kind of change would need to be behind a config option of some sort, trading off safety against low friction.
I could imagine a setting like "core.OperationWorktreeSafety", with settings "default" (current behavior - rebase disallows dirty worktrees, the others disallow dirty index), "strict" (all behave like current rebase) and "lax" (all behave like merge).
Quoted 8 lines
As discussed elsewhere, I would also like to (have an option to) treat untracked files as "worktree dirtiness"/unstaged changes in exactly the same way as changes to tracked files - but that's another topic :)
I'll prepare a v2 with index-safety-only for sequence-cherry-pick for now, please let me know if a (better-named) "core.OperationWorktreeSafety" option is something that you'd be interested in / that would make sense to you.
I think it's worth considering a config option. One problem though is that if the user has to actively enable it to get greater safety it wont be much help to new users who don't know about it and if it is on by default we'll be breaking someone's existing workflow.
Best Wishes
Phillip
Quoted 1 line
Thanks!
Hi Tao
Quoted 15 lines · Tao Klerks via GitGitGadget
From: Tao Klerks <[email protected]>
Cherry-pick, like merge or rebase, refuses to run when there are changes in the index. However, if a cherry-pick sequence is requested, this refusal happens "too late": when the cherry-pick sequence has already started, and an "--abort" or "--quit" is needed to resume normal operation.
Normally, when an operation is "in-progress" and you want to go back to where you were before, "--abort" is the right thing to run. If you run "git cherry-pick --abort" in this specific situation, however, your staged changes are destroyed as part of the abort! Generally speaking, the abort process assumes any changes in the index are part of the operation to be aborted.
Quoted 4 lines
Add an earlier check in the cherry-pick sequence process to ensure that the index is clean, introducing a new general "quit if index dirty" function derived from the existing worktree-level function used in rebase and pull. Also add a test.
Thanks for working on this, I think it useful to have this added safety check.
Quoted 60 lines
sequencer.c | 53 ++++++++++++++++------------ t/t3510-cherry-pick-sequence.sh | 10 ++++++ wt-status.c | 61 ++++++++++++++++++++++++++------- wt-status.h | 5 +++ 4 files changed, 94 insertions(+), 35 deletions(-)sequencer.c +22
-17@@ -3162,38 +3162,48 @@ static int walk_revs_populate_todo(struct todo_list *todo_list,return 0 ; } -static int create_seq_dir (struct repository *r) +static const char *cherry_pick_action_name (enum replay_action action) { +switch (action) { +case REPLAY_REVERT : +return "revert" ; +break ; +case REPLAY_PICK : +return "cherry-pick" ; +break ; +default : +BUG ("unexpected action in cherry_pick_action_name" ); + } +} + +static int create_seq_dir (struct repository *r,enum replay_action requested_action) { -enum replay_action action; +enum replay_action in_progress_action; +const char *in_progress_action_name =NULL ;const char *in_progress_error =NULL ;const char *in_progress_advice =NULL ; +const char *requested_action_name =NULL ;unsigned int advise_skip =refs_ref_exists (get_main_ref_store (r),"REVERT_HEAD" ) ||refs_ref_exists (get_main_ref_store (r),"CHERRY_PICK_HEAD" ); -if (!sequencer_get_last_command (r, &action)) { -switch (action) { -case REPLAY_REVERT : - in_progress_error =_ ("revert is already in progress" ); - in_progress_advice = -_ ("try \"git revert (--continue | %s--abort | --quit)\"" ); -break ; -case REPLAY_PICK : - in_progress_error =_ ("cherry-pick is already in progress" ); - in_progress_advice = -_ ("try \"git cherry-pick (--continue | %s--abort | --quit)\"" ); -break ; -default : -BUG ("unexpected action in create_seq_dir" ); - } +if (!sequencer_get_last_command (r, &in_progress_action)) { + in_progress_action_name =cherry_pick_action_name (in_progress_action); + in_progress_error =_ ("%s is already in progress" ); + in_progress_advice = +_ ("try \"git %s (--continue | %s--abort | --quit)\"" );
sequencer.c static int walk_revs_populate_todo(struct todo_list *todo_list, · line 3202
Quoted 10 lines
sequencer.c +2
-1}if (in_progress_error) { -error ("%s" , in_progress_error); +error (in_progress_error, in_progress_action_name);if (advice_enabled (ADVICE_SEQUENCER_IN_USE ))advise (in_progress_advice, + in_progress_action_name, advise_skip ?"--skip | " :"" );return -1 ; }
I found the changes up to this point a bit confusing. Maybe I've missed something but I don't think they are really related to fixing the bug described in the commit message. As such they're a distraction from the "real" fix.
sequencer.c static int walk_revs_populate_todo(struct todo_list *todo_list, · line 3203
Quoted 1 line
sequencer.c +1
-0+ requested_action_name =cherry_pick_action_name (requested_action);
We already have the function action_name() so I don't think we need to add cherry_pick_action_name(). Also the name of the new function is confusing as it may return "revert".
sequencer.c static int walk_revs_populate_todo(struct todo_list *todo_list, · line 3205
Quoted 2 lines
sequencer.c +2
-0+if (require_clean_index (r, requested_action_name, +_ ("Please commit or stash them." ),1 ,1 ))
How does this interact with "--no-commit"? I think the check that you refer to in the commit message is in do_pick_commit() where we have
if (opts->no_commit) {
/*
* We do not intend to commit immediately. We just want to
* merge the differences in, so let's compute the tree
* that represents the "current" state for the merge machinery
* to work on.
*/
if (write_index_as_tree(&head, r->index, r->index_file, 0, NULL))
return error(_("your index file is unmerged."));
} else {
unborn = repo_get_oid(r, "HEAD", &head);
/* Do we want to generate a root commit? */
if (is_pick_or_similar(command) && opts->have_squash_onto &&
oideq(&head, &opts->squash_onto)) {
if (is_fixup(command))
return error(_("cannot fixup root commit"));
flags |= CREATE_ROOT_COMMIT;
unborn = 1;
} else if (unborn)
oidcpy(&head, the_hash_algo->empty_tree);
if (index_differs_from(r, unborn ? empty_tree_oid_hex() : "HEAD",
NULL, 0))
return error_dirty_index(r, opts);
}I think it would be simpler to reuse the existing check by extracting the "else" clause above into a separate function in sequencer.c and call it here guarded by "if (!opts->no_commit)" as well as in that "else" clause in do_pick_commit()
Best Wishes
Phillip
Quoted 141 lines
sequencer.c +4
-4+return -1 ;if (mkdir (git_path_seq_dir (),0777 ) <0 )return error_errno (_ ("could not create sequencer directory '%s'" ),git_path_seq_dir ());@@ -5223,12 +5233,11 @@ int sequencer_pick_revisions(struct repository *r,/* * Start a new cherry-pick/ revert sequence; but -* first, make sure that an existing one isn't in -* progress +* first, make sure that the index is clean and that +* an existing one isn't in progress. */ -if (walk_revs_populate_todo (&todo_list, opts) || -create_seq_dir (r) <0 ) +create_seq_dir (r, opts->action) <0 )return -1 ;if (repo_get_oid (r,"HEAD" , &oid) && (opts->action ==REPLAY_REVERT ))return error (_ ("can't revert as initial commit" ));t/t3510-cherry-pick-sequence.sh +10
-0@@ -47,6 +47,16 @@ test_expect_success 'cherry-pick persists data on failure' ' test_path_is_file .git/sequencer/opts ' +test_expect_success 'cherry-pick sequence refuses to run on dirty index' ' + pristine_detach initial && + touch localindexchange && + git add localindexchange && + echo picking && + test_must_fail git cherry-pick initial..picked && + test_path_is_missing .git/sequencer && + test_must_fail git cherry-pick --abort +' + test_expect_success 'cherry-pick mid-cherry-pick-sequence' ' pristine_detach initial && test_must_fail git cherry-pick base..anotherpick &&wt-status.c +48
-13@@ -2616,15 +2616,12 @@ int has_uncommitted_changes(struct repository *r,return result; } -/** -* If the work tree has unstaged or uncommitted changes, dies with the -* appropriate message. -*/ -int require_clean_work_tree (struct repository *r, -const char *action, -const char *hint, -int ignore_submodules, -int gently) +static int require_clean_index_or_work_tree (struct repository *r, +const char *action, +const char *hint, +int ignore_submodules, +int check_index_only, +int gently) {struct lock_file lock_file =LOCK_INIT ;int err =0 , fd;@@ -2635,10 +2632,12 @@ int require_clean_work_tree(struct repository *r,repo_update_index_if_able (r, &lock_file);rollback_lock_file (&lock_file); -if (has_unstaged_changes (r, ignore_submodules)) { -/* TRANSLATORS: the action is e.g. "pull with rebase" */ -error (_ ("cannot %s: You have unstaged changes." ),_ (action)); - err =1 ; +if (!check_index_only) { +if (has_unstaged_changes (r, ignore_submodules)) { +/* TRANSLATORS: the action is e.g. "pull with rebase" */ +error (_ ("cannot %s: You have unstaged changes." ),_ (action)); + err =1 ; + } }if (has_uncommitted_changes (r, ignore_submodules)) {@@ -2659,3 +2658,39 @@ int require_clean_work_tree(struct repository *r,return err; } + +/** +* If the work tree has unstaged or uncommitted changes, dies with the +* appropriate message. +*/ +int require_clean_work_tree (struct repository *r, +const char *action, +const char *hint, +int ignore_submodules, +int gently) +{ +return require_clean_index_or_work_tree (r, + action, + hint, + ignore_submodules, +0 , + gently); +} + +/** +* If the work tree has uncommitted changes, dies with the appropriate +* message. +*/ +int require_clean_index (struct repository *r, +const char *action, +const char *hint, +int ignore_submodules, +int gently) +{ +return require_clean_index_or_work_tree (r, + action, + hint, + ignore_submodules, +1 , + gently); +}wt-status.h +5
-0@@ -181,5 +181,10 @@ int require_clean_work_tree(struct repository *repo,const char *hint, int ignore_submodules, int gently); +int require_clean_index (struct repository *repo, +const char *action, +const char *hint, +int ignore_submodules, +int gently);#endif /* STATUS_H */ base-commit:
4a714b37029a4b63dbd22f7d7ed81f7a0d693680
Quoted 4 lines · Phillip Wood
Hi Tao
On 28/05/2023 10:08, Tao Klerks via GitGitGadget wrote:
Quoted 9 lines
Quoted 2 lines
From: Tao Klerks <[email protected]>
<SNIP>
I found the changes up to this point a bit confusing. Maybe I've missed something but I don't think they are really related to fixing the bug described in the commit message. As such they're a distraction from the "real" fix.
Understood, thanks - *if* I kept them, they should be in a separate "prep refactor" commit.
The reason I did all this was just that I needed to build a new message that displayed the correct cherry-pick action name - something that was, in the existing code, done by repeating the entire advice message. I didn't want to do the same, and if I was going add what I needed to construct the message more dynamically I figured I should update the existing repetition-based approach.
Quoted 5 lines
Quoted 2 lines
+
requested_action_name=cherry_pick_action_name(requested_action);We already have the function
action_name()so I don't think we need to addcherry_pick_action_name().
The reason I had added a new one was that action_name() also supported "REPLAY_INTERACTIVE_REBASE", which should not be an option in the codepath that I was refactoring. I wanted to retain the existing "defensiveness", but that clearly got in the way of both brevity and clarity.
Quoted 2 lines
Also the name of the new function is
confusing as it may return "revert".
Yeah, the name was supposed to reflect the context ("cherry-pick logic which also covers revert, as opposed to rebase which also uses sequencer but is a substantially separate flow"), rather than the output value.
Quoted 32 lines
sequencer.c static int walk_revs_populate_todo(struct todo_list *todo_list, · line 3205
Quoted 3 lines
sequencer.c +2
-0+if (require_clean_index (r, requested_action_name, +_ ("Please commit or stash them." ),1 ,1 ))How does this interact with "--no-commit"? I think the check that you refer to in the commit message is in
do_pick_commit()where we haveif (opts->no_commit) { /* * We do not intend to commit immediately. We just want to * merge the differences in, so let's compute the tree * that represents the "current" state for the merge machinery * to work on. */ if (write_index_as_tree(&head, r->index, r->index_file, 0, NULL)) return error(_("your index file is unmerged.")); } else { unborn = repo_get_oid(r, "HEAD", &head); /* Do we want to generate a root commit? */ if (is_pick_or_similar(command) && opts->have_squash_onto && oideq(&head, &opts->squash_onto)) { if (is_fixup(command)) return error(_("cannot fixup root commit")); flags |= CREATE_ROOT_COMMIT; unborn = 1; } else if (unborn) oidcpy(&head, the_hash_algo->empty_tree); if (index_differs_from(r, unborn ? empty_tree_oid_hex() : "HEAD", NULL, 0)) return error_dirty_index(r, opts); }
Quoted 4 lines
I think it would be simpler to reuse the existing check by extracting the "else" clause above into a separate function in
sequencer.cand call it here guarded by "if (!opts->no_commit)" as well as in that "else" clause indo_pick_commit()
That sounds very plausible.
I will (very belatedly) have a go, and submit another version sometime soon.
Thanks so much for taking the time to review, and my apologies for the months-later context revival!