Thread (92 messages) 92 messages, 9 authors, 2021-12-01

Re: [PATCH v2 1/7] reset: behave correctly with sparse-checkout

From: Elijah Newren <hidden>
Date: 2021-10-06 01:46:58

Hi!

It appears Junio has already commented on this patch and in more
detail, but since I already typed up some comments I'll send them
along in case they are useful.

On Tue, Oct 5, 2021 at 6:20 AM Kevin Willford via GitGitGadget
[off-list ref] wrote:
From: Kevin Willford <redacted>

When using the sparse checkout feature, 'git reset' will add entries to
the index that will have the skip-worktree bit off but will leave the
working directory empty.
Yes, that seems like a problem.
File data is lost because the index version of
the files has been changed but there is nothing that is in the working
directory. This will cause the next 'git status' call to show either
deleted for files modified or deleting or nothing for files added. The
added files should be shown as untracked and modified files should be
shown as modified.
Why is the solution to add the files to the working tree rather than
to make sure the files have the skip-worktree bit set?  That's not at
all what I would have expected.
To fix this when the reset is running if there is not a file in the
working directory and if it will be missing with the new index entry or
was not missing in the previous version, we create the previous index
version of the file in the working directory so that status will report
correctly and the files will be availble for the user to deal with.
s/availble/available/
quoted hunk ↗ jump to hunk
This fixes a documented failure from t1092 that was created in 19a0acc
(t1092: test interesting sparse-checkout scenarios, 2021-01-23).

Signed-off-by: Kevin Willford <redacted>
Signed-off-by: Derrick Stolee <redacted>
Signed-off-by: Victoria Dye <redacted>
---
 builtin/reset.c                          | 24 ++++++++--
 t/t1092-sparse-checkout-compatibility.sh |  4 +-
 t/t7114-reset-sparse-checkout.sh         | 61 ++++++++++++++++++++++++
 3 files changed, 83 insertions(+), 6 deletions(-)
 create mode 100755 t/t7114-reset-sparse-checkout.sh
diff --git a/builtin/reset.c b/builtin/reset.c
index 51c9e2f43ff..3b75d3b2f20 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -25,6 +25,8 @@
 #include "cache-tree.h"
 #include "submodule.h"
 #include "submodule-config.h"
+#include "dir.h"
+#include "entry.h"

 #define REFRESH_INDEX_DELAY_WARNING_IN_MS (2 * 1000)
@@ -130,11 +132,27 @@ static void update_index_from_diff(struct diff_queue_struct *q,
        int intent_to_add = *(int *)data;

        for (i = 0; i < q->nr; i++) {
+               int pos;
                struct diff_filespec *one = q->queue[i]->one;
-               int is_missing = !(one->mode && !is_null_oid(&one->oid));
+               struct diff_filespec *two = q->queue[i]->two;
+               int is_in_reset_tree = one->mode && !is_null_oid(&one->oid);
Isn't !is_null_oid(&one->oid) redundant to checking one->mode?  When
does the diff machinery ever give you a non-zero mode with a null oid?

Also, is_in_reset_tree == !is_missing; I'll note that below.
                struct cache_entry *ce;

+               /*
+                * If the file being reset has `skip-worktree` enabled, we need
+                * to check it out to prevent the file from being hard reset.
I don't understand this comment.  If the file wasn't originally in the
index (is_missing), and is being added to it, and is correctly marked
as skip_worktree, and the file isn't in the working tree, then it
sounds like everything is already in a good state.  Files outside the
sparse checkout are meant to have the skip_worktree bit set and be
missing from the working tree.

Also, I don't know what you mean by 'hard reset' here.
+                */
+               pos = cache_name_pos(two->path, strlen(two->path));
+               if (pos >= 0 && ce_skip_worktree(active_cache[pos])) {
+                       struct checkout state = CHECKOUT_INIT;
+                       state.force = 1;
+                       state.refresh_cache = 1;
+                       state.istate = &the_index;
+
+                       checkout_entry(active_cache[pos], &state, NULL, NULL);
Does this introduce an error in the opposite direction from the one
stated in the commit message?  Namely we have two things that should
be in sync: the skip_worktree flag stating whether the file should be
present in the working directory (skip_worktree), and the question of
whether the file is actually in the working directory.  In the commit
message, you pointed out a case where the y were out of sync one way:
the skip_worktree flag was not set but the file was missing.  Here you
say the skip_worktree flag is set, but you add it to the working tree
anyway.

Or am I misunderstanding the code?
+               }
+
[I did some slight editing to the diff to make the next two parts
appear next to each other]
-               if (is_missing && !intent_to_add) {
+               if (!is_in_reset_tree && !intent_to_add) {
I thought this was some subtle bugfix or something, and spent a while
trying to figure it out, before realizing that is_in_reset_tree was
simply defined as !is_missing (for some reason I was assuming it was
dealing with two->mode while is_missing was looking at one->mode).  So
this is a simple variable renaming, which I think is probably good,
but I'd prefer if this was separated into a different patch to make it
easier to review.
quoted hunk ↗ jump to hunk
                        remove_file_from_cache(one->path);
                        continue;
                }
@@ -144,7 +162,7 @@ static void update_index_from_diff(struct diff_queue_struct *q,
                if (!ce)
                        die(_("make_cache_entry failed for path '%s'"),
                            one->path);
-               if (is_missing) {
+               if (!is_in_reset_tree) {
same note as above; the variable rename is good, but should be a separate patch.
quoted hunk ↗ jump to hunk
                        ce->ce_flags |= CE_INTENT_TO_ADD;
                        set_object_name_for_intent_to_add_entry(ce);
                }
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 886e78715fe..c5977152661 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -459,9 +459,7 @@ test_expect_failure 'blame with pathspec outside sparse definition' '
        test_all_match git blame deep/deeper2/deepest/a
 '

-# NEEDSWORK: a sparse-checkout behaves differently from a full checkout
-# in this scenario, but it shouldn't.
-test_expect_failure 'checkout and reset (mixed)' '
+test_expect_success 'checkout and reset (mixed)' '
        init_repos &&

        test_all_match git checkout -b reset-test update-deep &&
diff --git a/t/t7114-reset-sparse-checkout.sh b/t/t7114-reset-sparse-checkout.sh
new file mode 100755
index 00000000000..a8029707fb1
--- /dev/null
+++ b/t/t7114-reset-sparse-checkout.sh
@@ -0,0 +1,61 @@
+#!/bin/sh
+
+test_description='reset when using a sparse-checkout'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+       test_tick &&
+       echo "checkout file" >c &&
+       echo "modify file" >m &&
+       echo "delete file" >d &&
+       git add . &&
+       git commit -m "initial commit" &&
+       echo "added file" >a &&
+       echo "modification of a file" >m &&
+       git rm d &&
+       git add . &&
+       git commit -m "second commit" &&
+       git checkout -b endCommit
+'
+
+test_expect_success 'reset when there is a sparse-checkout' '
+       echo "/c" >.git/info/sparse-checkout &&
+       test_config core.sparsecheckout true &&
+       git checkout -B resetBranch &&
+       test_path_is_missing m &&
+       test_path_is_missing a &&
+       test_path_is_missing d &&
+       git reset HEAD~1 &&
+       echo "checkout file" >expect &&
+       test_cmp expect c &&
+       echo "added file" >expect &&
+       test_cmp expect a &&
+       echo "modification of a file" >expect &&
+       test_cmp expect m &&
+       test_path_is_missing d
+'
+
+test_expect_success 'reset after deleting file without skip-worktree bit' '
+       git checkout -f endCommit &&
+       git clean -xdf &&
+       cat >.git/info/sparse-checkout <<-\EOF &&
+       /c
+       /m
+       EOF
+       test_config core.sparsecheckout true &&
+       git checkout -B resetAfterDelete &&
+       test_path_is_file m &&
+       test_path_is_missing a &&
+       test_path_is_missing d &&
+       rm -f m &&
+       git reset HEAD~1 &&
+       echo "checkout file" >expect &&
+       test_cmp expect c &&
+       echo "added file" >expect &&
+       test_cmp expect a &&
+       test_path_is_missing m &&
+       test_path_is_missing d
+'
+
+test_done
--
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