diff mbox series

[v4,2/5] worktree: create init_worktree_config()

Message ID d262a76b448a495f00f460e9ed9439a74946de49.1643136134.git.gitgitgadget@gmail.com (mailing list archive)
State New, archived
Headers show
Series Sparse checkout: fix bug with worktree of bare repo | expand

Commit Message

Derrick Stolee Jan. 25, 2022, 6:42 p.m. UTC
From: Derrick Stolee <dstolee@microsoft.com>

Upgrading a repository to use extensions.worktreeConfig is non-trivial.
There are several steps involved, including moving some config settings
from the common config file to the main worktree's config.worktree file.
The previous change updated the documentation with all of these details.

Commands such as 'git sparse-checkout set' upgrade the repository to use
extensions.worktreeConfig without following these steps, causing some
user pain in some special cases.

Create a helper method, init_worktree_config(), that will be used in a
later change to fix this behavior within 'git sparse-checkout set'. The
method is carefully documented in worktree.h.

Note that we do _not_ upgrade the repository format version to 1 during
this process. The worktree config extension must be considered by Git
and third-party tools even if core.repositoryFormatVersion is 0 for
historical reasons documented in 11664196ac ("Revert
"check_repository_format_gently(): refuse extensions for old
repositories"", 2020-07-15). This is a special case for this extension,
and newer extensions (such as extensions.objectFormat) still need to
upgrade the repository format version.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 worktree.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 worktree.h | 19 +++++++++++++++
 2 files changed, 89 insertions(+)

Comments

Elijah Newren Jan. 27, 2022, 7:01 a.m. UTC | #1
On Tue, Jan 25, 2022 at 10:42 AM Derrick Stolee via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: Derrick Stolee <dstolee@microsoft.com>
>
> Upgrading a repository to use extensions.worktreeConfig is non-trivial.
> There are several steps involved, including moving some config settings
> from the common config file to the main worktree's config.worktree file.
> The previous change updated the documentation with all of these details.
>
> Commands such as 'git sparse-checkout set' upgrade the repository to use
> extensions.worktreeConfig without following these steps, causing some
> user pain in some special cases.
>
> Create a helper method, init_worktree_config(), that will be used in a
> later change to fix this behavior within 'git sparse-checkout set'. The
> method is carefully documented in worktree.h.

I was curious why you were only fixing `set` and not `init`, but I
looked ahead and it appears you are fixing both, since both use
set_config().  And I can see leaving out the mention of `init` since
it's deprecated.  Anyway, it's all good here, I'm basically just
thinking out loud...

> Note that we do _not_ upgrade the repository format version to 1 during
> this process. The worktree config extension must be considered by Git
> and third-party tools even if core.repositoryFormatVersion is 0 for
> historical reasons documented in 11664196ac ("Revert
> "check_repository_format_gently(): refuse extensions for old
> repositories"", 2020-07-15). This is a special case for this extension,
> and newer extensions (such as extensions.objectFormat) still need to
> upgrade the repository format version.
>
> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
> ---
>  worktree.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  worktree.h | 19 +++++++++++++++
>  2 files changed, 89 insertions(+)
>
> diff --git a/worktree.c b/worktree.c
> index 6f598dcfcdf..dc4ead4c8fb 100644
> --- a/worktree.c
> +++ b/worktree.c
> @@ -5,6 +5,7 @@
>  #include "worktree.h"
>  #include "dir.h"
>  #include "wt-status.h"
> +#include "config.h"
>
>  void free_worktrees(struct worktree **worktrees)
>  {
> @@ -826,3 +827,72 @@ int should_prune_worktree(const char *id, struct strbuf *reason, char **wtpath,
>         *wtpath = path;
>         return 0;
>  }
> +
> +static int move_config_setting(const char *key, const char *value,
> +                              const char *from_file, const char *to_file)
> +{
> +       if (git_config_set_in_file_gently(to_file, key, value))
> +               return error(_("unable to set %s in '%s'"), key, to_file);
> +       if (git_config_set_in_file_gently(from_file, key, NULL))
> +               return error(_("unable to unset %s in '%s'"), key, from_file);
> +       return 0;
> +}
> +
> +int init_worktree_config(struct repository *r)
> +{
> +       int res = 0;
> +       int bare = 0;
> +       struct config_set cs = { { 0 } };
> +       const char *core_worktree;
> +       char *common_config_file = xstrfmt("%s/config", r->commondir);
> +       char *main_worktree_file = xstrfmt("%s/config.worktree", r->commondir);
> +
> +       /*
> +        * If the extension is already enabled, then we can skip the
> +        * upgrade process.
> +        */
> +       if (repository_format_worktree_config)
> +               return 0;
> +       if ((res = git_config_set_gently("extensions.worktreeConfig", "true")))
> +               return error(_("failed to set extensions.worktreeConfig setting"));
> +
> +       git_configset_init(&cs);
> +       git_configset_add_file(&cs, common_config_file);
> +
> +       /*
> +        * If core.bare is true in the common config file, then we need to
> +        * move it to the base worktree's config file or it will break all
> +        * worktrees. If it is false, then leave it in place because it
> +        * _could_ be negating a global core.bare=true.
> +        */
> +       if (!git_configset_get_bool(&cs, "core.bare", &bare) && bare) {
> +               if ((res = move_config_setting("core.bare", "true",
> +                                              common_config_file,
> +                                              main_worktree_file)))
> +                       goto cleanup;
> +       }
> +       /*
> +        * If core.worktree is set, then the base worktree is located
> +        * somewhere different than the parent of the common Git dir.
> +        * Relocate that value to avoid breaking all worktrees with this
> +        * upgrade to worktree config.
> +        */
> +       if (!git_configset_get_string_tmp(&cs, "core.worktree", &core_worktree)) {
> +               if ((res = move_config_setting("core.worktree", core_worktree,
> +                                              common_config_file,
> +                                              main_worktree_file)))
> +                       goto cleanup;
> +       }
> +
> +       /*
> +        * Ensure that we use worktree config for the remaining lifetime
> +        * of the current process.
> +        */
> +       repository_format_worktree_config = 1;
> +
> +cleanup:
> +       git_configset_clear(&cs);
> +       free(common_config_file);
> +       free(main_worktree_file);
> +       return res;
> +}
> diff --git a/worktree.h b/worktree.h
> index 9e06fcbdf3d..5ea5fcc3647 100644
> --- a/worktree.h
> +++ b/worktree.h
> @@ -183,4 +183,23 @@ void strbuf_worktree_ref(const struct worktree *wt,
>                          struct strbuf *sb,
>                          const char *refname);
>
> +/**
> + * Enable worktree config for the first time. This will make the following
> + * adjustments:
> + *
> + * 1. Add extensions.worktreeConfig=true in the common config file.
> + *
> + * 2. If the common config file has a core.worktree value or core.bare is
> + *    set to true, then those values are moved to the main worktree's
> + *    config.worktree file.

This is a bit ambiguous.  If core.worktree is set and core.bare is
false, are both moved or only one?  I'm afraid folks won't understand
that it's just one from this description.


> + *
> + * If extensions.worktreeConfig is already true, then this method
> + * terminates early without any of the above steps. The existing config
> + * arrangement is assumed to be intentional.
> + *
> + * Returns 0 on success. Reports an error message and returns non-zero
> + * if any of these steps fail.
> + */
> +int init_worktree_config(struct repository *r);
> +
>  #endif
> --

Other than the ambiguity in worktree.h, this patch looks solid.
diff mbox series

Patch

diff --git a/worktree.c b/worktree.c
index 6f598dcfcdf..dc4ead4c8fb 100644
--- a/worktree.c
+++ b/worktree.c
@@ -5,6 +5,7 @@ 
 #include "worktree.h"
 #include "dir.h"
 #include "wt-status.h"
+#include "config.h"
 
 void free_worktrees(struct worktree **worktrees)
 {
@@ -826,3 +827,72 @@  int should_prune_worktree(const char *id, struct strbuf *reason, char **wtpath,
 	*wtpath = path;
 	return 0;
 }
+
+static int move_config_setting(const char *key, const char *value,
+			       const char *from_file, const char *to_file)
+{
+	if (git_config_set_in_file_gently(to_file, key, value))
+		return error(_("unable to set %s in '%s'"), key, to_file);
+	if (git_config_set_in_file_gently(from_file, key, NULL))
+		return error(_("unable to unset %s in '%s'"), key, from_file);
+	return 0;
+}
+
+int init_worktree_config(struct repository *r)
+{
+	int res = 0;
+	int bare = 0;
+	struct config_set cs = { { 0 } };
+	const char *core_worktree;
+	char *common_config_file = xstrfmt("%s/config", r->commondir);
+	char *main_worktree_file = xstrfmt("%s/config.worktree", r->commondir);
+
+	/*
+	 * If the extension is already enabled, then we can skip the
+	 * upgrade process.
+	 */
+	if (repository_format_worktree_config)
+		return 0;
+	if ((res = git_config_set_gently("extensions.worktreeConfig", "true")))
+		return error(_("failed to set extensions.worktreeConfig setting"));
+
+	git_configset_init(&cs);
+	git_configset_add_file(&cs, common_config_file);
+
+	/*
+	 * If core.bare is true in the common config file, then we need to
+	 * move it to the base worktree's config file or it will break all
+	 * worktrees. If it is false, then leave it in place because it
+	 * _could_ be negating a global core.bare=true.
+	 */
+	if (!git_configset_get_bool(&cs, "core.bare", &bare) && bare) {
+		if ((res = move_config_setting("core.bare", "true",
+					       common_config_file,
+					       main_worktree_file)))
+			goto cleanup;
+	}
+	/*
+	 * If core.worktree is set, then the base worktree is located
+	 * somewhere different than the parent of the common Git dir.
+	 * Relocate that value to avoid breaking all worktrees with this
+	 * upgrade to worktree config.
+	 */
+	if (!git_configset_get_string_tmp(&cs, "core.worktree", &core_worktree)) {
+		if ((res = move_config_setting("core.worktree", core_worktree,
+					       common_config_file,
+					       main_worktree_file)))
+			goto cleanup;
+	}
+
+	/*
+	 * Ensure that we use worktree config for the remaining lifetime
+	 * of the current process.
+	 */
+	repository_format_worktree_config = 1;
+
+cleanup:
+	git_configset_clear(&cs);
+	free(common_config_file);
+	free(main_worktree_file);
+	return res;
+}
diff --git a/worktree.h b/worktree.h
index 9e06fcbdf3d..5ea5fcc3647 100644
--- a/worktree.h
+++ b/worktree.h
@@ -183,4 +183,23 @@  void strbuf_worktree_ref(const struct worktree *wt,
 			 struct strbuf *sb,
 			 const char *refname);
 
+/**
+ * Enable worktree config for the first time. This will make the following
+ * adjustments:
+ *
+ * 1. Add extensions.worktreeConfig=true in the common config file.
+ *
+ * 2. If the common config file has a core.worktree value or core.bare is
+ *    set to true, then those values are moved to the main worktree's
+ *    config.worktree file.
+ *
+ * If extensions.worktreeConfig is already true, then this method
+ * terminates early without any of the above steps. The existing config
+ * arrangement is assumed to be intentional.
+ *
+ * Returns 0 on success. Reports an error message and returns non-zero
+ * if any of these steps fail.
+ */
+int init_worktree_config(struct repository *r);
+
 #endif