From: Teng Long <redacted>

When appending to a given notes object and the appended note is not
empty too, we will insert a blank line at first which separates the
existing note and the appended one, which as the separator.

Sometimes, we want to use a specified <text> as the separator. For
example, if we specify as:

    * --separator='------': we will insert "------\n" as the separator,
    because user do not provide the line break char at last, we will add
    the trailing '\n' compatibly.

    * --separator='------\n': we will insert as-is because it contains
    the line break at last.

    * --separator='': we specify an empty separator which means will
    append the message directly without inserting any separator at
    first.

    * not specified --separator option: will use '\n' as the separator
    when do appending and this is the default behavour.

Signed-off-by: Teng Long <redacted>
---
 Documentation/git-notes.txt | 18 +++++++++--
 builtin/notes.c             | 49 +++++++++++++++++++++++++++---
 t/t3301-notes.sh            | 59 +++++++++++++++++++++++++++++++++++++
 3 files changed, 120 insertions(+), 6 deletions(-)

diff --git a/Documentation/git-notes.txt b/Documentation/git-notes.txt
index efbc10f0f5..227fa88317 100644
--- a/Documentation/git-notes.txt
+++ b/Documentation/git-notes.txt

@@ -11,7 +11,7 @@ SYNOPSIS
 'git notes' [list [<object>]]
 'git notes' add [-f] [--allow-empty] [-F <file> | -m <msg> | (-c | -C) <object>] [<object>]
 'git notes' copy [-f] ( --stdin | <from-object> [<to-object>] )
-'git notes' append [--allow-empty] [-F <file> | -m <msg> | (-c | -C) <object>] [<object>]
+'git notes' append [--allow-empty] [--separator] [-F <file> | -m <msg> | (-c | -C) <object>] [<object>]
 'git notes' edit [--allow-empty] [<object>]
 'git notes' show [<object>]
 'git notes' merge [-v | -q] [-s <strategy> ] <notes-ref>

@@ -86,7 +86,11 @@ the command can read the input given to the `post-rewrite` hook.)
 
 append::
 	Append to the notes of an existing object (defaults to HEAD).
-	Creates a new notes object if needed.
+	Creates a new notes object if needed. If the note of the given
+	object and the note to be appended are not empty, a blank line
+	will be inserted between them as the separator ("blank line" is
+	the default behavior, `--separator` option supports to specify
+	a customized one).

 
 edit::
 	Edit the notes for a given object (defaults to HEAD).

@@ -159,6 +163,16 @@ OPTIONS
 	Allow an empty note object to be stored. The default behavior is
 	to automatically remove empty notes.
 
+--separator <text>::
+	Specify the <text> to be inserted between existing note and appended
+	message, the <text> acts as a separator.

+
 --ref <ref>::
 	Manipulate the notes tree in <ref>.  This overrides
 	`GIT_NOTES_REF` and the "core.notesRef" configuration.  The ref

diff --git a/builtin/notes.c b/builtin/notes.c
index f2efb3736c..6746ad3232 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c

@@ -24,6 +24,8 @@
 #include "notes-utils.h"
 #include "worktree.h"
 
+static char *separator = "\n";
+
 static const char * const git_notes_usage[] = {
 	N_("git notes [--ref <notes-ref>] [list [<object>]]"),
 	N_("git notes [--ref <notes-ref>] add [-f] [--allow-empty] [-m <msg> | -F <file> | (-c | -C) <object>] [<object>]"),

@@ -209,7 +211,7 @@ static void write_note_data(struct note_data *d, struct object_id *oid)
 	}
 }
 
-static int parse_msg_arg(const struct option *opt, const char *arg, int unset)
+static int parse_msg_arg_add(const struct option *opt, const char *arg, int unset)
 {
 	struct note_data *d = opt->value;
 

@@ -225,6 +227,43 @@ static int parse_msg_arg(const struct option *opt, const char *arg, int unset)
 	return 0;
 }
 
+static void insert_separator(struct strbuf *message)
+{
+	const char *insert;
+
+	if (!separator)
+		separator = "\n";
+	if (*separator == '\0')