notes: correct documentation of DWIMery for notes references

expand_notes_ref is used by --ref from git-notes(1) and --notes from the
git log to find the full refname of a notes reference. Previously the
documentation of these options was not clear about what sorts of
expansions would be performed. Fix the documentation to clearly and
accurately describe the behavior of the expansions.

Add a test for this expansion when using git notes get-ref in order to
prevent future patches from changing this behavior.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-notes.txt

@@ -162,7 +162,9 @@ OPTIONS
 --ref <ref>::
 	Manipulate the notes tree in <ref>.  This overrides
 	'GIT_NOTES_REF' and the "core.notesRef" configuration.  The ref
-	is taken to be in `refs/notes/` if it is not qualified.
+	specifies the full refname when it begins with `refs/notes/`; when it
+	begins with `notes/`, `refs/` and otherwise `refs/notes/` is prefixed
+	to form a full name of the ref.
 
 --ignore-missing::
 	Do not consider it an error to request removing notes from an

Documentation/pretty-options.txt

@@ -55,8 +55,9 @@ By default, the notes shown are from the notes refs listed in the
 environment overrides). See linkgit:git-config[1] for more details.
 +
 With an optional '<ref>' argument, show this notes ref instead of the
-default notes ref(s). The ref is taken to be in `refs/notes/` if it
-is not qualified.
+default notes ref(s). The ref specifies the full refname when it begins
+with `refs/notes/`; when it begins with `notes/`, `refs/` and otherwise
+`refs/notes/` is prefixed to form a full name of the ref.
 +
 Multiple --notes options can be combined to control which notes are
 being displayed. Examples: "--notes=foo" will show only notes from

t/t3301-notes.sh

@@ -1122,6 +1122,12 @@ test_expect_success 'git notes copy diagnoses too many or too few parameters' '
 	test_must_fail git notes copy one two three
 '
 
+test_expect_success 'git notes get-ref expands refs/heads/master to refs/notes/refs/heads/master' '
+	test_unconfig core.notesRef &&
+	sane_unset GIT_NOTES_REF &&
+	test "$(git notes --ref=refs/heads/master get-ref)" = "refs/notes/refs/heads/master"
+'
+
 test_expect_success 'git notes get-ref (no overrides)' '
 	test_unconfig core.notesRef &&
 	sane_unset GIT_NOTES_REF &&