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Re: [RFC/PATCH] Add multiple workdir support to branch/checkout

From
Jay Soffian <jaysoffian@gmail.com>
Date
Oct 5, 2011, 15:24 UTC
Message-ID
<1317828285-66581-1-git-send-email-jaysoffian@gmail.com>
In-Reply-To
<7vmxdg9j3r.fsf@alter.siamese.dyndns.org>
On Wed, Oct 5, 2011 at 12:07 AM, Junio C Hamano <gitster@pobox.com> wrote:
Show 29 quoted lines
> Jay Soffian <jaysoffian@gmail.com> writes:
>> @@ -734,6 +758,9 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
>>               parse_commit(new->commit);
>>       }
>>
>> +     if (opts->record_checkouts)
>> +             check_if_checked_out(opts, new->name);
>
> The close brace we can see in the context closes "if (!new->name) {", so
> this codepath is very well prepared to be called with new->name == NULL.
>
> Is check_if_checked_out() prepared to be called with name == NULL and do
> the right thing?
>
>> @@ -743,6 +770,14 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
>>
>>       update_refs_for_switch(opts, &old, new);
>>
>> +     if (opts->record_checkouts) {
>> +             const char *work_tree = get_git_work_tree();
>> +             struct branch *branch = branch_get(old.name);
>> +             if (branch->work_tree && !strcmp(branch->work_tree, work_tree))
>> +                     record_checkout(old.name, "");
>> +             record_checkout(new->name, work_tree);
>> +     }
>> +
>
> Likewise for new->name, but also old.name which is only set when old.path
> is set and begins with "refs/heads/" and otherwise NULL.

I was more looking for feedback on the idea than the implementation, but here's a better implementation. Still an RFC so no tests yet.

-- >8 --
Subject: [RFC/PATCH] Teach branch/checkout about workdirs

When using 'git new-workdir', there is no safety mechanism to prevent the same branch from being checked out twice, nor to prevent a checked out branch from being deleted.

Teach 'checkout' to record the workdir path using 'branch.<name>.checkout' when switching branches. We can then easily check if a branch is already checked out in another workdir before switching to that branch. Add a similar check before deleting a branch.

Allow 'checkout -f' to force the checkout and issue a warning instead of an error.

Guard this behavior behind 'core.recordCheckouts', which we will teach 'git new-workdir' to set in a followup commit.

Note: when switching away from a branch, we set 'branch.<name>.checkout'
to the empty string, instead of deleting it entirely, since git_config()
otherwise leaves behind an empty section which it does not re-use.
Signed-off-by: Jay Soffian <jaysoffian@gmail.com>
---
 builtin/branch.c   |   10 ++++++++++
 builtin/checkout.c |   45 +++++++++++++++++++++++++++++++++++++++++++++
 remote.c           |    4 ++++
 remote.h           |    1 +
 4 files changed, 60 insertions(+), 0 deletions(-)
diff --git a/builtin/branch.c b/builtin/branch.c
index f49596f826..6ce1a5b133 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -182,6 +182,16 @@ static int delete_branches(int argc, const char **argv, int force, int kinds)
 			ret = 1;
 			continue;
 		}
+		if (kinds == REF_LOCAL_BRANCH) {
+			struct branch *branch = branch_get(bname.buf);
+			if (branch->work_tree && strlen(branch->work_tree)) {
+				error(_("Cannot delete the branch '%s' "
+					"which is currently checked out in '%s'"),
+				      bname.buf, branch->work_tree);
+				ret = 1;
+				continue;
+			}
+		}
 
 		free(name);
 
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 5e356a6c61..b3c658ffd4 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -33,6 +33,7 @@ struct checkout_opts {
 	int force_detach;
 	int writeout_stage;
 	int writeout_error;
+	int record_checkouts;
 
 	/* not set by parse_options */
 	int branch_exists;
@@ -508,6 +509,20 @@ static void detach_advice(const char *old_path, const char *new_name)
 	fprintf(stderr, fmt, new_name);
 }
 
+static void record_checkout(const char *name, const char *new_work_tree)
+{
+	struct strbuf key = STRBUF_INIT;
+	strbuf_addf(&key, "branch.%s.checkout", name);
+	if (new_work_tree) { /* reserve name */
+		git_config_set(key.buf, new_work_tree);
+	} else { /* release name if we reserved it */
+		struct branch *branch = branch_get(name);
+		if (!strcmp(branch->work_tree, get_git_work_tree()))
+			git_config_set(key.buf, "");
+	}
+	strbuf_release(&key);
+}
+
 static void update_refs_for_switch(struct checkout_opts *opts,
 				   struct branch_info *old,
 				   struct branch_info *new)
@@ -556,6 +571,8 @@ static void update_refs_for_switch(struct checkout_opts *opts,
 				detach_advice(old->path, new->name);
 			describe_detached_head(_("HEAD is now at"), new->commit);
 		}
+		if (opts->record_checkouts && old->name)
+			record_checkout(old->name, NULL);
 	} else if (new->path) {	/* Switch branches. */
 		create_symref("HEAD", new->path, msg.buf);
 		if (!opts->quiet) {
@@ -580,6 +597,11 @@ static void update_refs_for_switch(struct checkout_opts *opts,
 			if (!file_exists(ref_file) && file_exists(log_file))
 				remove_path(log_file);
 		}
+		if (opts->record_checkouts) {
+			if (old->name)
+				record_checkout(old->name, NULL);
+			record_checkout(new->name, get_git_work_tree());
+		}
 	}
 	remove_branch_state();
 	strbuf_release(&msg);
@@ -709,6 +731,23 @@ static void orphaned_commit_warning(struct commit *commit)
 	for_each_ref(clear_commit_marks_from_one_ref, NULL);
 }
 
+static void check_if_checked_out(struct checkout_opts *opts, const char *name)
+{
+	struct branch *branch;
+	if (!opts->record_checkouts)
+		return;
+	branch = branch_get(name);
+	if (branch->work_tree && strlen(branch->work_tree) &&
+	    strcmp(branch->work_tree, get_git_work_tree())) {
+		if (opts->force)
+			warning(_("branch '%s' is currently checked out"
+				  " in '%s'"), name, branch->work_tree);
+		else
+			die(_("branch '%s' is currently checked out"
+			      " in '%s'"), name, branch->work_tree);
+	}
+}
+
 static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 {
 	int ret = 0;
@@ -732,6 +771,8 @@ static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
 		if (!new->commit)
 			die(_("You are on a branch yet to be born"));
 		parse_commit(new->commit);
+	} else if (opts->record_checkouts) {
+		check_if_checked_out(opts, new->name);
 	}
 
 	ret = merge_working_tree(opts, &old, new);
@@ -756,6 +797,10 @@ static int git_checkout_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.recordcheckouts")) {
+		struct checkout_opts *opts = cb;
+		opts->record_checkouts = git_config_bool(var, value);
+	}
 	if (!prefixcmp(var, "submodule."))
 		return parse_submodule_config_option(var, value);
 
diff --git a/remote.c b/remote.c
index b8ecfa5d95..2bc063dae8 100644
--- a/remote.c
+++ b/remote.c
@@ -364,6 +364,10 @@ static int handle_config(const char *key, const char *value, void *cb)
 			if (!value)
 				return config_error_nonbool(key);
 			add_merge(branch, xstrdup(value));
+		} else if (!strcmp(subkey, ".checkout")) {
+			if (!value)
+				return config_error_nonbool(key);
+			branch->work_tree = xstrdup(value);
 		}
 		return 0;
 	}
diff --git a/remote.h b/remote.h
index 9a30a9dba6..4103ec7e31 100644
--- a/remote.h
+++ b/remote.h
@@ -126,6 +126,7 @@ int remote_find_tracking(struct remote *remote, struct refspec *refspec);
 struct branch {
 	const char *name;
 	const char *refname;
+	const char *work_tree;
 
 	const char *remote_name;
 	struct remote *remote;

-- 
1.7.7.4.g39e02c
Previous: Junio C HamanoNext: Jay Soffian
Message 33 of 35 in “Add multiple workdir support to branch/checkout”
  1. Add multiple workdir support to branch/checkoutJay Soffian, Oct 5, 2011
  2. Jay SoffianOct 5, 2011
  3. Nguyen Thai Ngoc DuyOct 5, 2011
  4. Jay SoffianOct 5, 2011
  5. Junio C HamanoOct 5, 2011
  6. Jay SoffianOct 5, 2011
  7. Junio C HamanoOct 5, 2011
  8. Jay SoffianOct 5, 2011
  9. Andreas KreyOct 5, 2011
  10. Jay SoffianOct 5, 2011
  11. Jonathan NiederOct 5, 2011
  12. Jay SoffianOct 5, 2011
  13. Jonathan NiederOct 5, 2011
  14. Junio C HamanoOct 5, 2011
  15. Jay SoffianOct 5, 2011
  16. Jay SoffianOct 5, 2011
  17. Nguyen Thai Ngoc DuyOct 5, 2011
  18. Junio C HamanoOct 5, 2011
  19. Nguyen Thai Ngoc DuyOct 5, 2011
  20. Junio C HamanoOct 5, 2011
  21. Jay SoffianOct 6, 2011
  22. Junio C HamanoOct 6, 2011
  23. Jay SoffianOct 6, 2011
  24. Junio C HamanoOct 6, 2011
  25. Jay SoffianOct 6, 2011
  26. Junio C HamanoOct 6, 2011
  27. Jay SoffianOct 6, 2011
  28. Nguyen Thai Ngoc DuyOct 6, 2011
  29. Bernhard R. LinkOct 6, 2011
  30. Jeff KingOct 6, 2011
  31. Nguyen Thai Ngoc DuyOct 5, 2011
  32. Junio C HamanoOct 5, 2011
  33. Jay SoffianOct 5, 2011
  34. Jay SoffianOct 5, 2011
  35. Julián LanderrecheOct 8, 2011

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