diff --git a/core/ssb.js b/core/ssb.js
index f6b6b639..c40272d9 100644
--- a/core/ssb.js
+++ b/core/ssb.js
@@ -219,7 +219,9 @@ function ebtReplicateSendClock(request, have) {
 	}
 
 	var to_send = {}
-	for (let id of ids) {
+	var offset = Math.floor(Math.random() * ids.length);
+	for (var i = 0; i < ids.length; i++) {
+		var id = ids[(i + offset) % ids.length];
 		if (last_sent[id] === undefined || message[id] > last_sent[id]) {
 			last_sent[id] = to_send[id] = message[id] === -1 ? -1 : message[id] << 1;
 		}
diff --git a/src/main.c b/src/main.c
index a5235d12..f045e0fb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -569,20 +569,35 @@ static int _tf_command_check(const char* file, int argc, char* argv[])
 	int extra_count = 0;
 	const char *err = NULL;
 	XOPT_PARSE(file, XOPT_CTX_KEEPFIRST | XOPT_CTX_STRICT, options, &args, argc, (const char**)argv, &extra_count, &extras, &err, stderr, "post [options]", "options:", NULL, 15);
-	if (extras)
-	{
-		free((void*)extras);
-	}
 	if (err)
 	{
+		if (extras)
+		{
+			free((void*)extras);
+		}
 		fprintf(stderr, "Error: %s\n", err);
 		return 2;
 	}
 
+	bool result = true;
 	sqlite3* db = NULL;
 	sqlite3_open("db.sqlite", &db);
-	bool result = tf_ssb_db_check(db);
+	if (extra_count)
+	{
+		for (int i = 0; i < extra_count; i++)
+		{
+			result = result && tf_ssb_db_check(db, extras[i]);
+		}
+	}
+	else
+	{
+		result = tf_ssb_db_check(db, NULL);
+	}
 	sqlite3_close(db);
+	if (extras)
+	{
+		free((void*)extras);
+	}
 	return result ? EXIT_SUCCESS : EXIT_FAILURE;
 
 xopt_help:
diff --git a/src/ssb.c b/src/ssb.c
index d5d03565..9f9b48d8 100644
--- a/src/ssb.c
+++ b/src/ssb.c
@@ -512,6 +512,25 @@ static const uint8_t* _utf8_to_cp(const uint8_t* ch, uint32_t* out_cp)
 	return ch + actual_len;
 }
 
+static uint32_t _cp_to_utf16(uint32_t cp, uint16_t* out_h, uint16_t* out_l)
+{
+	if (cp < 0x10000)
+	{
+		*out_h = 0;
+		*out_l = cp & 0xffff;
+		return cp;
+	}
+	else
+	{
+		uint32_t t = cp - 0x10000;
+		uint32_t h = ((t << 12) >> 22) + 0xd800;
+		uint32_t l = ((t << 22) >> 22) + 0xdc00;
+		*out_h = h & 0xffff;
+		*out_l = l & 0xffff;
+		return (h << 16) | (l & 0xffff);
+	}
+}
+
 void tf_ssb_calculate_message_id(JSContext* context, JSValue message, char* out_id, size_t out_id_size)
 {
 	JSValue idval = JS_JSONStringify(context, message, JS_NULL, JS_NewInt32(context, 2));
@@ -525,7 +544,17 @@ void tf_ssb_calculate_message_id(JSContext* context, JSValue message, char* out_
 	{
 		uint32_t cp = 0;
 		p = _utf8_to_cp(p, &cp);
-		*write_pos++ = (cp & 0xff);
+		uint16_t h = 0;
+		uint16_t l = 0;
+		_cp_to_utf16(cp, &h, &l);
+		if (h)
+		{
+			*write_pos++ = h & 0xff;
+		}
+		if (l)
+		{
+			*write_pos++ = l & 0xff;
+		}
 	}
 	size_t latin1_len = write_pos - (uint8_t*)latin1;
 	*write_pos++ = '\0';
diff --git a/src/ssb.db.c b/src/ssb.db.c
index 2e58919c..d77aa387 100644
--- a/src/ssb.db.c
+++ b/src/ssb.db.c
@@ -545,14 +545,21 @@ bool _tf_ssb_update_message_id(sqlite3* db, const char* old_id, const char* new_
 	return success;
 }
 
-bool tf_ssb_db_check(sqlite3* db)
+bool tf_ssb_db_check(sqlite3* db, const char* check_author)
 {
 	JSRuntime* runtime = JS_NewRuntime();
 	JSContext* context = JS_NewContext(runtime);
 
 	sqlite3_stmt* statement = NULL;
-	if (sqlite3_prepare(db, "SELECT id, previous, author, sequence, timestamp, hash, content, signature, sequence_before_author FROM messages ORDER BY author, sequence", -1, &statement, NULL) == SQLITE_OK)
+	int result = check_author ?
+		sqlite3_prepare(db, "SELECT id, previous, author, sequence, timestamp, hash, content, signature, sequence_before_author FROM messages WHERE author = ? ORDER BY author, sequence", -1, &statement, NULL) :
+		sqlite3_prepare(db, "SELECT id, previous, author, sequence, timestamp, hash, content, signature, sequence_before_author FROM messages ORDER BY author, sequence", -1, &statement, NULL);
+	if (result == SQLITE_OK)
 	{
+		if (check_author)
+		{
+			sqlite3_bind_text(statement, 1, check_author, -1, NULL);
+		}
 		char previous_id[k_id_base64_len];
 		while (sqlite3_step(statement) == SQLITE_ROW)
 		{
diff --git a/src/ssb.db.h b/src/ssb.db.h
index 1e6f3145..20f8c6ed 100644
--- a/src/ssb.db.h
+++ b/src/ssb.db.h
@@ -16,4 +16,4 @@ bool tf_ssb_db_get_latest_message_by_author(tf_ssb_t* ssb, const char* author, i
 void tf_ssb_db_visit_query(tf_ssb_t* ssb, const char* query, const JSValue binds, void (*callback)(JSValue row, void* user_data), void* user_data);
 
 typedef struct sqlite3 sqlite3;
-bool tf_ssb_db_check(sqlite3* db);
+bool tf_ssb_db_check(sqlite3* db, const char* author);