Merge branch 'jc/orphan-unborn'

Doc updates to clarify what an "unborn branch" means.

* jc/orphan-unborn:
  orphan/unborn: fix use of 'orphan' in end-user facing messages
  orphan/unborn: add to the glossary and use them consistently

Documentation/config/advice.txt

@@ -140,6 +140,6 @@ advice.*::
 		Advice shown when a fast-forward is not possible.
 	worktreeAddOrphan::
 		Advice shown when a user tries to create a worktree from an
-		invalid reference, to instruct how to create a new orphan
+		invalid reference, to instruct how to create a new unborn
 		branch instead.
 --

Documentation/git-checkout.txt

@@ -217,7 +217,7 @@ variable.
 	below for details.
 
 --orphan <new-branch>::
-	Create a new 'orphan' branch, named `<new-branch>`, started from
+	Create a new unborn branch, named `<new-branch>`, started from
 	`<start-point>` and switch to it.  The first commit made on this
 	new branch will have no parents and it will be the root of a new
 	history totally disconnected from all the other branches and

Documentation/git-switch.txt

@@ -176,7 +176,7 @@ name, the guessing is aborted.  You can explicitly give a name with
 	`branch.autoSetupMerge` configuration variable is true.
 
 --orphan <new-branch>::
-	Create a new 'orphan' branch, named `<new-branch>`. All
+	Create a new unborn branch, named `<new-branch>`. All
 	tracked files are removed.
 
 --ignore-other-worktrees::

Documentation/git-worktree.txt

@@ -99,7 +99,7 @@ command will refuse to create the worktree (unless `--force` is used).
 If `<commit-ish>` is omitted, neither `--detach`, or `--orphan` is
 used, and there are no valid local branches (or remote branches if
 `--guess-remote` is specified) then, as a convenience, the new worktree is
-associated with a new orphan branch named `<branch>` (after
+associated with a new unborn branch named `<branch>` (after
 `$(basename <path>)` if neither `-b` or `-B` is used) as if `--orphan` was
 passed to the command. In the event the repository has a remote and
 `--guess-remote` is used, but no remote or local branches exist, then the
@@ -234,7 +234,7 @@ This can also be set up as the default behaviour by using the
 
 --orphan::
 	With `add`, make the new worktree and index empty, associating
-	the worktree with a new orphan/unborn branch named `<new-branch>`.
+	the worktree with a new unborn branch named `<new-branch>`.
 
 --porcelain::
 	With `list`, output in an easy-to-parse format for scripts.

Documentation/glossary-content.txt

@@ -314,6 +314,12 @@ This commit is referred to as a "merge commit", or sometimes just a
 [[def_octopus]]octopus::
 	To <<def_merge,merge>> more than two <<def_branch,branches>>.
 
+[[def_orphan]]orphan::
+	The act of getting on a <<def_branch,branch>> that does not
+	exist yet (i.e., an <<def_unborn,unborn>> branch).  After
+	such an operation, the commit first created becomes a commit
+	without a parent, starting a new history.
+
 [[def_origin]]origin::
 	The default upstream <<def_repository,repository>>. Most projects have
 	at least one upstream project which they track. By default
@@ -697,6 +703,18 @@ The most notable example is `HEAD`.
 	object,
 	etc.
 
+[[def_unborn]]unborn::
+	The <<def_HEAD,HEAD>> can point at a <<def_branch,branch>>
+	that does not yet exist and that does not have any commit on
+	it yet, and such a branch is called an unborn branch.  The
+	most typical way users encounter an unborn branch is by
+	creating a repository anew without cloning from elsewhere.
+	The HEAD would point at the 'main' (or 'master', depending
+	on your configuration) branch that is yet to be born.  Also
+	some operations can get you on an unborn branch with their
+	<<def_orphan,orphan>> option.
+
+
 [[def_unmerged_index]]unmerged index::
 	An <<def_index,index>> which contains unmerged
 	<<def_index_entry,index entries>>.

builtin/checkout.c

@@ -1650,7 +1650,7 @@ static struct option *add_common_switch_branch_options(
 			parse_opt_tracking_mode),
 		OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
 			   PARSE_OPT_NOCOMPLETE),
-		OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
+		OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unborn branch")),
 		OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
 			   N_("update ignored files (default)"),
 			   PARSE_OPT_NOCOMPLETE),

builtin/worktree.c

@@ -49,14 +49,14 @@
 	_("No possible source branch, inferring '--orphan'")
 
 #define WORKTREE_ADD_ORPHAN_WITH_DASH_B_HINT_TEXT \
-	_("If you meant to create a worktree containing a new orphan branch\n" \
+	_("If you meant to create a worktree containing a new unborn branch\n" \
 	"(branch with no commits) for this repository, you can do so\n" \
 	"using the --orphan flag:\n" \
 	"\n" \
 	"    git worktree add --orphan -b %s %s\n")
 
 #define WORKTREE_ADD_ORPHAN_NO_DASH_B_HINT_TEXT \
-	_("If you meant to create a worktree containing a new orphan branch\n" \
+	_("If you meant to create a worktree containing a new unborn branch\n" \
 	"(branch with no commits) for this repository, you can do so\n" \
 	"using the --orphan flag:\n" \
 	"\n" \
@@ -784,7 +784,7 @@ static int add(int ac, const char **av, const char *prefix)
 			   N_("create a new branch")),
 		OPT_STRING('B', NULL, &new_branch_force, N_("branch"),
 			   N_("create or reset a branch")),
-		OPT_BOOL(0, "orphan", &opts.orphan, N_("create unborn/orphaned branch")),
+		OPT_BOOL(0, "orphan", &opts.orphan, N_("create unborn branch")),
 		OPT_BOOL('d', "detach", &opts.detach, N_("detach HEAD at named commit")),
 		OPT_BOOL(0, "checkout", &opts.checkout, N_("populate the new working tree")),
 		OPT_BOOL(0, "lock", &keep_locked, N_("keep the new working tree locked")),

t/t2400-worktree-add.sh

@@ -437,7 +437,7 @@ test_wt_add_orphan_hint () {
 		git -C repo switch --orphan noref &&
 		test_must_fail git -C repo worktree add $opts foobar/ 2>actual &&
 		! grep "error: unknown switch" actual &&
-		grep "hint: If you meant to create a worktree containing a new orphan branch" actual &&
+		grep "hint: If you meant to create a worktree containing a new unborn branch" actual &&
 		if [ $use_branch -eq 1 ]
 		then
 			grep -E "^hint: +git worktree add --orphan -b [^ ]+ [^ ]+$" actual
@@ -458,7 +458,7 @@ test_expect_success "'worktree add' doesn't show orphan hint in bad/orphan HEAD
 	(cd repo && test_commit commit) &&
 	test_must_fail git -C repo worktree add --quiet foobar_branch foobar/ 2>actual &&
 	! grep "error: unknown switch" actual &&
-	! grep "hint: If you meant to create a worktree containing a new orphan branch" actual
+	! grep "hint: If you meant to create a worktree containing a new unborn branch" actual
 '
 
 test_expect_success 'local clone from linked checkout' '
@@ -731,7 +731,7 @@ test_expect_success 'git worktree --no-guess-remote option overrides config' '
 test_dwim_orphan () {
 	local info_text="No possible source branch, inferring '--orphan'" &&
 	local fetch_error_text="fatal: No local or remote refs exist despite at least one remote" &&
-	local orphan_hint="hint: If you meant to create a worktree containing a new orphan branch" &&
+	local orphan_hint="hint: If you meant to create a worktree containing a new unborn branch" &&
 	local invalid_ref_regex="^fatal: invalid reference: " &&
 	local bad_combo_regex="^fatal: options '[-a-z]*' and '[-a-z]*' cannot be used together" &&