make git worktree add dwim more

The previous rounds were at
https://public-inbox.org/git/[email protected]/,
https://public-inbox.org/git/[email protected]/,
https://public-inbox.org/git/[email protected]/,
https://public-inbox.org/git/[email protected]/ and
https://public-inbox.org/git/[email protected].

Thanks Junio for the review of the last round!

Changes since the last round:

- rephrased documentation and commit messaegs a bit use the
- established pattern and call git_config only once, instead of calling it multiple times.

Interdiff below:

index fd841886ef..89ad0faecf 100644
@@ -116,11 +116,11 @@ OPTIONS
 	in linkgit:git-read-tree[1].
 
 --[no-]guess-remote::
-	With `add`, instead of creating a new branch from HEAD when
-	`<commit-ish>` is not given, if there exists a tracking branch
-	in exactly one remote matching the basename of the path, base
-	the new branch on the remote-tracking branch, and mark the
-	remote-tracking branch as "upstream" from the new branch.
+	With `worktree add <path>`, withouth `<commit-ish>`, instead
+	of creating a new branch from HEAD, if there exists a tracking
+	branch in exactly one remote matching the basename of `<path>,
+	base the new branch on the remote-tracking branch, and mark
+	the remote-tracking branch as "upstream" from the new branch.
 +
 This can also be set up as the default behaviour by using the
 `worktree.guessRemote` config option.

index 426aea8761..002a569a11 100644
@@ -43,7 +43,7 @@ static int git_worktree_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	return 0;
+	return git_default_config(var, value, cb);
 }
 
 static int prune_worktree(const char *id, struct strbuf *reason)

@@ -371,8 +371,6 @@ static int add(int ac, const char **av, const char *prefix)
 		OPT_END()
 	};
 
-	git_config(git_worktree_config, NULL);
-
 	memset(&opts, 0, sizeof(opts));
 	opts.checkout = 1;
 	ac = parse_options(ac, av, prefix, options, worktree_usage, 0);

@@ -603,7 +601,7 @@ int cmd_worktree(int ac, const char **av, const char *prefix)
 		OPT_END()
 	};
 
-	git_config(git_default_config, NULL);
+	git_config(git_worktree_config, NULL);
 
 	if (ac < 2)
 		usage_with_options(worktree_usage, options);

Thomas Gummerer (6):
checkout: factor out functions to new lib file
worktree: add can be created from any commit-ish
worktree: add --[no-]track option to the add subcommand
worktree: make add <path> <branch> dwim
worktree: add --guess-remote flag to add subcommand add worktree.guessRemote config option

 Documentation/config.txt       |  10 ++++
 Documentation/git-worktree.txt |  44 ++++++++++----
 Makefile                       |   1 +
 builtin/checkout.c             |  41 +------------
 builtin/worktree.c             |  46 ++++++++++++++-
 checkout.c                     |  43 ++++++++++++++
 checkout.h                     |  13 +++++
 t/t2025-worktree-add.sh        | 130 +++++++++++++++++++++++++++++++++++++++++
 8 files changed, 277 insertions(+), 51 deletions(-)
 create mode 100644 checkout.c
 create mode 100644 checkout.h

2.15.0.426.gb06021eeb