Re: [PATCH v3 04/11] unpack-trees: introduce preserve_ignored to unpack_trees_options

On Wed, Sep 29 2021, Elijah Newren wrote:

On Wed, Sep 29, 2021 at 2:27 AM Ævar Arnfjörð Bjarmason
[off-list ref] wrote:

quoted

On Mon, Sep 27 2021, Elijah Newren via GitGitGadget wrote:

quoted

From: Elijah Newren <redacted>

Currently, every caller of unpack_trees() that wants to ensure ignored
files are overwritten by default needs to:
   * allocate unpack_trees_options.dir
   * flip the DIR_SHOW_IGNORED flag in unpack_trees_options.dir->flags
   * call setup_standard_excludes
AND then after the call to unpack_trees() needs to
   * call dir_clear()
   * deallocate unpack_trees_options.dir
That's a fair amount of boilerplate, and every caller uses identical
code.  Make this easier by instead introducing a new boolean value where
the default value (0) does what we want so that new callers of
unpack_trees() automatically get the appropriate behavior.  And move all
the handling of unpack_trees_options.dir into unpack_trees() itself.

While preserve_ignored = 0 is the behavior we feel is the appropriate
default, we defer fixing commands to use the appropriate default until a
later commit.  So, this commit introduces several locations where we
manually set preserve_ignored=1.  This makes it clear where code paths
were previously preserving ignored files when they should not have been;
a future commit will flip these to instead use a value of 0 to get the
behavior we want.

Signed-off-by: Elijah Newren <redacted>
---
 builtin/am.c        |  3 +++
 builtin/checkout.c  | 11 ++---------
 builtin/clone.c     |  2 ++
 builtin/merge.c     |  2 ++
 builtin/read-tree.c | 13 +++----------
 builtin/reset.c     |  2 ++
 builtin/stash.c     |  3 +++
 merge-ort.c         |  8 +-------
 merge-recursive.c   |  8 +-------
 merge.c             |  8 +-------
 reset.c             |  2 ++
 sequencer.c         |  2 ++
 unpack-trees.c      | 10 ++++++++++
 unpack-trees.h      |  1 +
 14 files changed, 35 insertions(+), 40 deletions(-)

diff --git a/builtin/am.c b/builtin/am.c
index e4a0ff9cd7c..1ee70692bc3 100644
--- a/builtin/am.c
+++ b/builtin/am.c

@@ -1918,6 +1918,9 @@ static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
      opts.update = 1;
      opts.merge = 1;
      opts.reset = reset;
+     if (!reset)
+             /* FIXME: Default should be to remove ignored files */
+             opts.preserve_ignored = 1;
      opts.fn = twoway_merge;
      init_tree_desc(&t[0], head->buffer, head->size);
      init_tree_desc(&t[1], remote->buffer, remote->size);

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 5335435d616..5e7957dd068 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c

@@ -648,6 +648,7 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o,
      opts.skip_unmerged = !worktree;
      opts.reset = 1;
      opts.merge = 1;
+     opts.preserve_ignored = 0;
      opts.fn = oneway_merge;
      opts.verbose_update = o->show_progress;
      opts.src_index = &the_index;

@@ -746,11 +747,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
                                     new_branch_info->commit ?
                                     &new_branch_info->commit->object.oid :
                                     &new_branch_info->oid, NULL);
-             if (opts->overwrite_ignore) {
-                     topts.dir = xcalloc(1, sizeof(*topts.dir));
-                     topts.dir->flags |= DIR_SHOW_IGNORED;
-                     setup_standard_excludes(topts.dir);
-             }
+             topts.preserve_ignored = !opts->overwrite_ignore;
              tree = parse_tree_indirect(old_branch_info->commit ?
                                         &old_branch_info->commit->object.oid :
                                         the_hash_algo->empty_tree);

@@ -760,10 +757,6 @@ static int merge_working_tree(const struct checkout_opts *opts,
              init_tree_desc(&trees[1], tree->buffer, tree->size);

              ret = unpack_trees(2, trees, &topts);
-             if (topts.dir) {
-                     dir_clear(topts.dir);
-                     FREE_AND_NULL(topts.dir);
-             }
              clear_unpack_trees_porcelain(&topts);
              if (ret == -1) {
                      /*

diff --git a/builtin/clone.c b/builtin/clone.c
index ff1d3d447a3..be1c3840d62 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c

@@ -687,6 +687,8 @@ static int checkout(int submodule_progress)
      opts.update = 1;
      opts.merge = 1;
      opts.clone = 1;
+     /* FIXME: Default should be to remove ignored files */
+     opts.preserve_ignored = 1;
      opts.fn = oneway_merge;
      opts.verbose_update = (option_verbosity >= 0);
      opts.src_index = &the_index;

diff --git a/builtin/merge.c b/builtin/merge.c
index 3fbdacc7db4..1e5fff095fc 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c

@@ -680,6 +680,8 @@ static int read_tree_trivial(struct object_id *common, struct object_id *head,
      opts.verbose_update = 1;
      opts.trivial_merges_only = 1;
      opts.merge = 1;
+     /* FIXME: Default should be to remove ignored files */
+     opts.preserve_ignored = 1;
      trees[nr_trees] = parse_tree_indirect(common);
      if (!trees[nr_trees++])
              return -1;

diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index 73cb957a69b..443d206eca6 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c

@@ -201,11 +201,9 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
      if ((opts.update || opts.index_only) && !opts.merge)
              die("%s is meaningless without -m, --reset, or --prefix",
                  opts.update ? "-u" : "-i");
-     if (opts.update && !opts.reset) {
-             CALLOC_ARRAY(opts.dir, 1);
-             opts.dir->flags |= DIR_SHOW_IGNORED;
-             setup_standard_excludes(opts.dir);
-     }
+     if (opts.update && !opts.reset)
+             opts.preserve_ignored = 0;
+     /* otherwise, opts.preserve_ignored is irrelevant */
      if (opts.merge && !opts.index_only)
              setup_work_tree();

@@ -245,11 +243,6 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
      if (unpack_trees(nr_trees, t, &opts))
              return 128;

-     if (opts.dir) {
-             dir_clear(opts.dir);
-             FREE_AND_NULL(opts.dir);
-     }
-
      if (opts.debug_unpack || opts.dry_run)
              return 0; /* do not write the index out */

diff --git a/builtin/reset.c b/builtin/reset.c
index 51c9e2f43ff..7f38656f018 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c

@@ -67,6 +67,8 @@ static int reset_index(const char *ref, const struct object_id *oid, int reset_t
      case KEEP:
      case MERGE:
              opts.update = 1;
+             /* FIXME: Default should be to remove ignored files */
+             opts.preserve_ignored = 1;
              break;
      case HARD:
              opts.update = 1;

diff --git a/builtin/stash.c b/builtin/stash.c
index 8f42360ca91..88287b890d5 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c

@@ -258,6 +258,9 @@ static int reset_tree(struct object_id *i_tree, int update, int reset)
      opts.merge = 1;
      opts.reset = reset;
      opts.update = update;
+     if (update && !reset)
+             /* FIXME: Default should be to remove ignored files */
+             opts.preserve_ignored = 1;
      opts.fn = oneway_merge;

      if (unpack_trees(nr_trees, t, &opts))

diff --git a/merge-ort.c b/merge-ort.c
index 35aa979c3a4..0d64ec716bd 100644
--- a/merge-ort.c
+++ b/merge-ort.c

@@ -4045,11 +4045,7 @@ static int checkout(struct merge_options *opt,
      unpack_opts.quiet = 0; /* FIXME: sequencer might want quiet? */
      unpack_opts.verbose_update = (opt->verbosity > 2);
      unpack_opts.fn = twoway_merge;
-     if (1/* FIXME: opts->overwrite_ignore*/) {
-             CALLOC_ARRAY(unpack_opts.dir, 1);
-             unpack_opts.dir->flags |= DIR_SHOW_IGNORED;
-             setup_standard_excludes(unpack_opts.dir);
-     }
+     unpack_opts.preserve_ignored = 0; /* FIXME: !opts->overwrite_ignore*/
      parse_tree(prev);
      init_tree_desc(&trees[0], prev->buffer, prev->size);
      parse_tree(next);

@@ -4057,8 +4053,6 @@ static int checkout(struct merge_options *opt,

      ret = unpack_trees(2, trees, &unpack_opts);
      clear_unpack_trees_porcelain(&unpack_opts);
-     dir_clear(unpack_opts.dir);
-     FREE_AND_NULL(unpack_opts.dir);
      return ret;
 }

diff --git a/merge-recursive.c b/merge-recursive.c
index 233d9f686ad..2be3f5d4044 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c

@@ -411,9 +411,7 @@ static int unpack_trees_start(struct merge_options *opt,
      else {
              opt->priv->unpack_opts.update = 1;
              /* FIXME: should only do this if !overwrite_ignore */
-             CALLOC_ARRAY(opt->priv->unpack_opts.dir, 1);
-             opt->priv->unpack_opts.dir->flags |= DIR_SHOW_IGNORED;
-             setup_standard_excludes(opt->priv->unpack_opts.dir);
+             opt->priv->unpack_opts.preserve_ignored = 0;
      }
      opt->priv->unpack_opts.merge = 1;
      opt->priv->unpack_opts.head_idx = 2;

@@ -428,10 +426,6 @@ static int unpack_trees_start(struct merge_options *opt,
      init_tree_desc_from_tree(t+2, merge);

      rc = unpack_trees(3, t, &opt->priv->unpack_opts);
-     if (opt->priv->unpack_opts.dir) {
-             dir_clear(opt->priv->unpack_opts.dir);
-             FREE_AND_NULL(opt->priv->unpack_opts.dir);
-     }
      cache_tree_free(&opt->repo->index->cache_tree);

      /*

diff --git a/merge.c b/merge.c
index 6e736881d90..2382ff66d35 100644
--- a/merge.c
+++ b/merge.c

@@ -53,7 +53,6 @@ int checkout_fast_forward(struct repository *r,
      struct unpack_trees_options opts;
      struct tree_desc t[MAX_UNPACK_TREES];
      int i, nr_trees = 0;
-     struct dir_struct dir = DIR_INIT;
      struct lock_file lock_file = LOCK_INIT;

      refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);

@@ -80,11 +79,7 @@ int checkout_fast_forward(struct repository *r,
      }

      memset(&opts, 0, sizeof(opts));
-     if (overwrite_ignore) {
-             dir.flags |= DIR_SHOW_IGNORED;
-             setup_standard_excludes(&dir);
-             opts.dir = &dir;
-     }
+     opts.preserve_ignored = !overwrite_ignore;

      opts.head_idx = 1;
      opts.src_index = r->index;

@@ -101,7 +96,6 @@ int checkout_fast_forward(struct repository *r,
              clear_unpack_trees_porcelain(&opts);
              return -1;
      }
-     dir_clear(&dir);
      clear_unpack_trees_porcelain(&opts);

      if (write_locked_index(r->index, &lock_file, COMMIT_LOCK))

diff --git a/reset.c b/reset.c
index 79310ae071b..41b3e2d88de 100644
--- a/reset.c
+++ b/reset.c

@@ -56,6 +56,8 @@ int reset_head(struct repository *r, struct object_id *oid, const char *action,
      unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
      unpack_tree_opts.update = 1;
      unpack_tree_opts.merge = 1;
+     /* FIXME: Default should be to remove ignored files */
+     unpack_tree_opts.preserve_ignored = 1;
      init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
      if (!detach_head)
              unpack_tree_opts.reset = 1;

diff --git a/sequencer.c b/sequencer.c
index 614d56f5e21..098566c68d9 100644
--- a/sequencer.c
+++ b/sequencer.c

@@ -3699,6 +3699,8 @@ static int do_reset(struct repository *r,
      unpack_tree_opts.fn = oneway_merge;
      unpack_tree_opts.merge = 1;
      unpack_tree_opts.update = 1;
+     /* FIXME: Default should be to remove ignored files */
+     unpack_tree_opts.preserve_ignored = 1;
      init_checkout_metadata(&unpack_tree_opts.meta, name, &oid, NULL);

      if (repo_read_index_unmerged(r)) {

diff --git a/unpack-trees.c b/unpack-trees.c
index 8ea0a542da8..1e4eae1dc7d 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c

@@ -1707,6 +1707,12 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
              ensure_full_index(o->dst_index);
      }

+     if (!o->preserve_ignored) {
+             CALLOC_ARRAY(o->dir, 1);
+             o->dir->flags |= DIR_SHOW_IGNORED;
+             setup_standard_excludes(o->dir);
+     }
+
      if (!core_apply_sparse_checkout || !o->update)
              o->skip_sparse_checkout = 1;
      if (!o->skip_sparse_checkout && !o->pl) {

@@ -1868,6 +1874,10 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 done:
      if (free_pattern_list)
              clear_pattern_list(&pl);
+     if (o->dir) {
+             dir_clear(o->dir);
+             FREE_AND_NULL(o->dir);
+     }
      trace2_region_leave("unpack_trees", "unpack_trees", the_repository);
      trace_performance_leave("unpack_trees");
      return ret;

diff --git a/unpack-trees.h b/unpack-trees.h
index 2d88b19dca7..f98cfd49d7b 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h

@@ -49,6 +49,7 @@ struct unpack_trees_options {
      unsigned int reset,
                   merge,
                   update,
+                  preserve_ignored,
                   clone,
                   index_only,
                   nontrivial_merge,

I think getting rid of the boilerplate makes sense, but it doesn't sound
from the commit message like you've considered just making that "struct
dir*" member a "struct dir" instead.

That simplifies things a lot, i.e. we can just DIR_INIT it, and don't
need every caller to malloc/free it.

See the next patch in the series.  :-)

Ah!

quoted

Sometimes a pointer makes sense, but in this case the "struct
unpack_trees_options" can just own it.

I did make it internal to unpack_trees_options in the next patch, but
kept it as a pointer just because that let me know whether it was used
or not.  I guess I could have added a boolean as well.  But I don't
actually allocate anything, because it's either a NULL pointer, or a
pointer to something on the stack.  So, I do get to just use DIR_INIT.

I think I'm probably missing something. I just made it allocated on the
stack by the caller using "struct unpack_trees_options", but then you
end up having a dir* in the struct, but that's only filled in as a
pointer to the stack variable? Maybe there's some subtlety I'm missing
here...