create_tmp_packfile(): a helper function

Factor out a small logic out of the private write_pack_file() function
in builtin/pack-objects.c

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/pack-objects.c

@@ -584,16 +584,10 @@ static void write_pack_file(void)
 		unsigned char sha1[20];
 		char *pack_tmp_name = NULL;
 
-		if (pack_to_stdout) {
+		if (pack_to_stdout)
 			f = sha1fd_throughput(1, "<stdout>", progress_state);
-		} else {
-			char tmpname[PATH_MAX];
-			int fd;
-			fd = odb_mkstemp(tmpname, sizeof(tmpname),
-					 "pack/tmp_pack_XXXXXX");
-			pack_tmp_name = xstrdup(tmpname);
-			f = sha1fd(fd, pack_tmp_name);
-		}
+		else
+			f = create_tmp_packfile(&pack_tmp_name);
 
 		offset = write_pack_header(f, nr_remaining);
 		if (!offset)

pack-write.c

@@ -328,3 +328,13 @@ int encode_in_pack_object_header(enum object_type type, uintmax_t size, unsigned
 	*hdr = c;
 	return n;
 }
+
+struct sha1file *create_tmp_packfile(char **pack_tmp_name)
+{
+	char tmpname[PATH_MAX];
+	int fd;
+
+	fd = odb_mkstemp(tmpname, sizeof(tmpname), "pack/tmp_pack_XXXXXX");
+	*pack_tmp_name = xstrdup(tmpname);
+	return sha1fd(fd, *pack_tmp_name);
+}

pack.h

@@ -84,4 +84,7 @@ extern int encode_in_pack_object_header(enum object_type, uintmax_t, unsigned ch
 #define PH_ERROR_PACK_SIGNATURE	(-2)
 #define PH_ERROR_PROTOCOL	(-3)
 extern int read_pack_header(int fd, struct pack_header *);
+
+extern struct sha1file *create_tmp_packfile(char **pack_tmp_name);
+
 #endif