Derrick Stolee via GitGitGadget wrote:
> From: Derrick Stolee <derrickstolee@xxxxxxxxxx>
>
> The 'read_replace_objects' constant is initialized by git_default_config
> (if core.useReplaceRefs is disabled) and within setup_git_env (if
> GIT_NO_REPLACE_OBJECTS) is set. To ensure that this variable cannot be
> set accidentally in other places, wrap it in a replace_refs_enabled()
> method.
>
> This allows us to remove the global from being recognized outside of
> replace-objects.c.
>
> Further, a future change will help prevent the variable from being read
> before it is initialized. Centralizing its access is an important first
> step.
>
> Signed-off-by: Derrick Stolee <derrickstolee@xxxxxxxxxx>
> ---
> commit-graph.c | 4 +---
> environment.c | 1 -
> log-tree.c | 2 +-
> replace-object.c | 7 +++++++
> replace-object.h | 15 ++++++++++++++-
> 5 files changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/commit-graph.c b/commit-graph.c
> index 43558b4d9b0..95873317bf7 100644
> --- a/commit-graph.c
> +++ b/commit-graph.c
> @@ -203,14 +203,12 @@ static struct commit_graph *alloc_commit_graph(void)
> return g;
> }
>
> -extern int read_replace_refs;
> -
> static int commit_graph_compatible(struct repository *r)
> {
> if (!r->gitdir)
> return 0;
>
> - if (read_replace_refs) {
> + if (replace_refs_enabled(r)) {
> prepare_replace_object(r);
> if (hashmap_get_size(&r->objects->replace_map->map))
> return 0;
This and the other 'read_replace_refs' -> 'replace_refs_enabled()'
replacements all look good. Although we're not using the 'struct repository'
argument yet, I see that it'll be used in patch 3 - adding the (unused) arg
here helps avoid the extra churn there.
> diff --git a/replace-object.c b/replace-object.c
> index ceec81c940c..cf91c3ba456 100644
> --- a/replace-object.c
> +++ b/replace-object.c
> @@ -85,7 +85,14 @@ const struct object_id *do_lookup_replace_object(struct repository *r,
> die(_("replace depth too high for object %s"), oid_to_hex(oid));
> }
>
> +static int read_replace_refs = 1;
> +
> void disable_replace_refs(void)
> {
> read_replace_refs = 0;
> }
> +
> +int replace_refs_enabled(struct repository *r)
> +{
> + return read_replace_refs;
> +}
> diff --git a/replace-object.h b/replace-object.h
> index 7786d4152b0..b141075023e 100644
> --- a/replace-object.h
> +++ b/replace-object.h
> @@ -27,6 +27,19 @@ void prepare_replace_object(struct repository *r);
> const struct object_id *do_lookup_replace_object(struct repository *r,
> const struct object_id *oid);
>
> +
> +/*
> + * Some commands disable replace-refs unconditionally, and otherwise each
> + * repository could alter the core.useReplaceRefs config value.
> + *
> + * Return 1 if and only if all of the following are true:
> + *
> + * a. disable_replace_refs() has not been called.
> + * b. GIT_NO_REPLACE_OBJECTS is unset or zero.
> + * c. the given repository does not have core.useReplaceRefs=false.
> + */
> +int replace_refs_enabled(struct repository *r);
Since the purpose of this function is to access global state, would
'environment.[c|h]' be a more appropriate place for it (and
'disable_replace_refs()', for that matter)? There's also some precedent;
'set_shared_repository()' and 'get_shared_repository()' have a very similar
design to what you've added here.
