pop3-migration: Added pop3_migration_skip_size_check setting

If we know that we're not going to be able to match any messages by sizes,
we might as well not ask for the messages' sizes. This is useful at least
with Yahoo.

src/plugins/pop3-migration/pop3-migration-plugin.c

@@ -49,6 +49,7 @@ struct pop3_migration_mail_storage {
 	unsigned int all_mailboxes:1;
 	unsigned int pop3_all_hdr_sha1_set:1;
 	unsigned int ignore_missing_uidls:1;
+	unsigned int skip_size_check:1;
 };
 
 struct pop3_migration_mailbox {
@@ -267,7 +268,7 @@ static int pop3_map_read(struct mail_storage *storage, struct mailbox *pop3_box)
 	struct mail *mail;
 	struct pop3_uidl_map *map;
 	const char *uidl;
-	uoff_t size;
+	uoff_t size = (uoff_t)-1;
 	int ret = 0;
 
 	if (array_is_created(&mstorage->pop3_uidl_map)) {
@@ -288,14 +289,17 @@ static int pop3_map_read(struct mail_storage *storage, struct mailbox *pop3_box)
 	search_args = mail_search_build_init();
 	mail_search_build_add_all(search_args);
 	ctx = mailbox_search_init(t, search_args, NULL,
+				  mstorage->skip_size_check ? 0 :
 				  MAIL_FETCH_PHYSICAL_SIZE, NULL);
 	mail_search_args_unref(&search_args);
 
 	while (mailbox_search_next(ctx, &mail)) {
 		/* get the size with LIST instead of RETR */
 		mail->lookup_abort = MAIL_LOOKUP_ABORT_READ_MAIL;
 
-		if (mail_get_physical_size(mail, &size) < 0) {
+		if (mstorage->skip_size_check)
+			;
+		else if (mail_get_physical_size(mail, &size) < 0) {
 			i_error("pop3_migration: Failed to get size for msg %u: %s",
 				mail->seq,
 				mailbox_get_last_error(pop3_box, NULL));
@@ -383,13 +387,15 @@ pop3_map_read_hdr_hashes(struct mail_storage *storage, struct mailbox *pop3_box,
 static int imap_map_read(struct mailbox *box)
 {
 	struct pop3_migration_mailbox *mbox = POP3_MIGRATION_CONTEXT(box);
+	struct pop3_migration_mail_storage *mstorage =
+		POP3_MIGRATION_CONTEXT(box->storage);
 	struct mailbox_status status;
         struct mailbox_transaction_context *t;
 	struct mail_search_args *search_args;
 	struct mail_search_context *ctx;
 	struct mail *mail;
 	struct imap_msg_map *map;
-	uoff_t psize;
+	uoff_t psize = (uoff_t)-1;
 	int ret = 0;
 
 	mailbox_get_open_status(box, STATUS_MESSAGES, &status);
@@ -401,11 +407,14 @@ static int imap_map_read(struct mailbox *box)
 	search_args = mail_search_build_init();
 	mail_search_build_add_all(search_args);
 	ctx = mailbox_search_init(t, search_args, NULL,
+				  mstorage->skip_size_check ? 0 :
 				  MAIL_FETCH_PHYSICAL_SIZE, NULL);
 	mail_search_args_unref(&search_args);
 
 	while (mailbox_search_next(ctx, &mail)) {
-		if (mail_get_physical_size(mail, &psize) < 0) {
+		if (mstorage->skip_size_check)
+			;
+		else if (mail_get_physical_size(mail, &psize) < 0) {
 			i_error("pop3_migration: Failed to get psize for imap uid %u: %s",
 				mail->uid,
 				mailbox_get_last_error(box, NULL));
@@ -742,6 +751,9 @@ static void pop3_migration_mail_storage_created(struct mail_storage *storage)
 	mstorage->ignore_missing_uidls =
 		mail_user_plugin_getenv(storage->user,
 			"pop3_migration_ignore_missing_uidls") != NULL;
+	mstorage->skip_size_check =
+		mail_user_plugin_getenv(storage->user,
+			"pop3_migration_skip_size_check") != NULL;
 
 	MODULE_CONTEXT_SET(storage, pop3_migration_storage_module, mstorage);
 }