From f54ca6ae72e32e34f2042a93f92949e3ded11a36 Mon Sep 17 00:00:00 2001
From: Jacob Keller <jacob.keller@gmail.com>
Date: Tue, 27 Aug 2024 14:27:17 -0700
Subject: [PATCH] check-mailmap: add options for additional mailmap sources

The git check-mailmap command reads the mailmap from either the default
.mailmap location and then from the mailmap.blob and mailmap.file
configurations.

A following change to git send-email will want to support new
configuration options based on the configured identity. The
identity-based configuration and options only make sense in the context
of git send-email.

Expose the read_mailmap_file and read_mailmap_blob functions from
mailmap.c.  Teach git check-mailmap the --mailmap-file and
--mailmap-blob options which load the additional mailmap sources.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-check-mailmap.txt | 10 ++++++++++
 builtin/check-mailmap.c             |  7 +++++++
 mailmap.c                           |  9 +++------
 mailmap.h                           |  7 +++++++
 4 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/Documentation/git-check-mailmap.txt b/Documentation/git-check-mailmap.txt
index 7747e38e25..966c91c46a 100644
--- a/Documentation/git-check-mailmap.txt
+++ b/Documentation/git-check-mailmap.txt
@@ -27,6 +27,16 @@ OPTIONS
 	Read contacts, one per line, from the standard input after exhausting
 	contacts provided on the command-line.
 
+--mailmap-file=<file>::
+	In addition to any configured mailmap files, read the specified
+	mailmap file. Entries in this file take precedence over entries in
+	either the default mailmap file or any configured mailmap file.
+
+--mailmap-blob=<blob>::
+	Like `--mailmap-file`, but consider the value as a reference to a
+	blob in the repository. If both `--mailmap-file` and
+	`--mailmap-blob` are specified, entries in `--mailmap-file` will
+	take precedence.
 
 OUTPUT
 ------
diff --git a/builtin/check-mailmap.c b/builtin/check-mailmap.c
index 6b7fb53494..2334b57222 100644
--- a/builtin/check-mailmap.c
+++ b/builtin/check-mailmap.c
@@ -9,6 +9,7 @@
 #include "write-or-die.h"
 
 static int use_stdin;
+static const char *mailmap_file, *mailmap_blob;
 static const char * const check_mailmap_usage[] = {
 N_("git check-mailmap [<options>] <contact>..."),
 NULL
@@ -16,6 +17,8 @@ NULL
 
 static const struct option check_mailmap_options[] = {
 	OPT_BOOL(0, "stdin", &use_stdin, N_("also read contacts from stdin")),
+	OPT_FILENAME(0, "mailmap-file", &mailmap_file, N_("read additional mailmap entries from file")),
+	OPT_STRING(0, "mailmap-blob", &mailmap_blob, N_("blob"), N_("read additional mailmap entries from blob")),
 	OPT_END()
 };
 
@@ -56,6 +59,10 @@ int cmd_check_mailmap(int argc, const char **argv, const char *prefix)
 		die(_("no contacts specified"));
 
 	read_mailmap(&mailmap);
+	if (mailmap_blob)
+		read_mailmap_blob(&mailmap, mailmap_blob);
+	if (mailmap_file)
+		read_mailmap_file(&mailmap, mailmap_file, 0);
 
 	for (i = 0; i < argc; ++i)
 		check_mailmap(&mailmap, argv[i]);
diff --git a/mailmap.c b/mailmap.c
index 2d0212f444..4212e553e7 100644
--- a/mailmap.c
+++ b/mailmap.c
@@ -142,11 +142,8 @@ static void read_mailmap_line(struct string_list *map, char *buffer)
 		add_mapping(map, name1, email1, name2, email2);
 }
 
-/* Flags for read_mailmap_file() */
-#define MAILMAP_NOFOLLOW (1<<0)
-
-static int read_mailmap_file(struct string_list *map, const char *filename,
-			     unsigned flags)
+int read_mailmap_file(struct string_list *map, const char *filename,
+		      unsigned flags)
 {
 	char buffer[1024];
 	FILE *f;
@@ -186,7 +183,7 @@ static void read_mailmap_string(struct string_list *map, char *buf)
 	}
 }
 
-static int read_mailmap_blob(struct string_list *map, const char *name)
+int read_mailmap_blob(struct string_list *map, const char *name)
 {
 	struct object_id oid;
 	char *buf;
diff --git a/mailmap.h b/mailmap.h
index cbda9bc5e0..908365e1bf 100644
--- a/mailmap.h
+++ b/mailmap.h
@@ -6,6 +6,13 @@ struct string_list;
 extern char *git_mailmap_file;
 extern char *git_mailmap_blob;
 
+/* Flags for read_mailmap_file() */
+#define MAILMAP_NOFOLLOW (1<<0)
+
+int read_mailmap_file(struct string_list *map, const char *filename,
+		      unsigned flags);
+int read_mailmap_blob(struct string_list *map, const char *name);
+
 int read_mailmap(struct string_list *map);
 void clear_mailmap(struct string_list *map);