make skipping of failed stores more thorough

in the case of imap stores, the failure is bound to the server config,
not just the store config.

that means that the storage of the failure state needs to be private to
the driver, accessible only through a function.

src/driver.h

@@ -41,7 +41,6 @@ typedef struct store_conf {
 	const char *trash;
 	uint max_size; /* off_t is overkill */
 	char trash_remote_new, trash_only_new;
-	char failed;
 } store_conf_t;
 
 /* For message->flags */
@@ -249,6 +248,9 @@ struct driver {
 
 	/* Get approximate amount of memory occupied by the driver. */
 	int (*memory_usage)( store_t *ctx );
+
+	/* Get the FAIL_* state of the driver. */
+	int (*fail_state)( store_conf_t *conf );
 };
 
 void free_generic_messages( message_t * );

src/drv_imap.c

@@ -57,6 +57,7 @@ typedef struct imap_server_conf {
 #ifdef HAVE_LIBSSL
 	char ssl_type;
 #endif
+	char failed;
 } imap_server_conf_t;
 
 typedef struct imap_store_conf {
@@ -2156,7 +2157,7 @@ imap_open_store_bail( imap_store_t *ctx, int failed )
 {
 	void (*cb)( store_t *srv, void *aux ) = ctx->callbacks.imap_open;
 	void *aux = ctx->callback_aux;
-	ctx->gen.conf->failed = failed;
+	((imap_store_conf_t *)ctx->gen.conf)->server->failed = failed;
 	imap_cancel_store( &ctx->gen );
 	cb( 0, aux );
 }
@@ -2658,6 +2659,14 @@ imap_memory_usage( store_t *gctx )
 	return ctx->buffer_mem + ctx->conn.buffer_mem;
 }
 
+/******************* imap_fail_state *******************/
+
+static int
+imap_fail_state( store_conf_t *gconf )
+{
+	return ((imap_store_conf_t *)gconf)->server->failed;
+}
+
 /******************* imap_parse_store *******************/
 
 imap_server_conf_t *servers, **serverapp = &servers;
@@ -2937,4 +2946,5 @@ struct driver imap_driver = {
 	imap_cancel_cmds,
 	imap_commit_cmds,
 	imap_memory_usage,
+	imap_fail_state,
 };

src/drv_maildir.c

@@ -57,6 +57,7 @@ typedef struct maildir_store_conf {
 	int alt_map;
 #endif /* USE_DB */
 	char info_delimiter;
+	char failed;
 	char *info_prefix, *info_stop; /* precalculated from info_delimiter */
 } maildir_store_conf_t;
 
@@ -141,12 +142,12 @@ maildir_validate_path( store_conf_t *conf )
 
 	if (!conf->path) {
 		error( "Maildir error: store '%s' has no Path\n", conf->name );
-		conf->failed = FAIL_FINAL;
+		((maildir_store_conf_t *)conf)->failed = FAIL_FINAL;
 		return -1;
 	}
 	if (stat( conf->path, &st ) || !S_ISDIR(st.st_mode)) {
 		error( "Maildir error: cannot open store '%s'\n", conf->path );
-		conf->failed = FAIL_FINAL;
+		((maildir_store_conf_t *)conf)->failed = FAIL_FINAL;
 		return -1;
 	}
 	return 0;
@@ -432,7 +433,7 @@ maildir_validate( const char *box, int create, maildir_store_t *ctx )
 			return DRV_BOX_BAD;
 		if (make_box_dir( buf, bl )) {
 			sys_error( "Maildir error: cannot create mailbox '%s'", box );
-			ctx->gen.conf->failed = FAIL_FINAL;
+			((maildir_store_conf_t *)ctx->gen.conf)->failed = FAIL_FINAL;
 			maildir_invoke_bad_callback( &ctx->gen );
 			return DRV_CANCELED;
 		}
@@ -1630,6 +1631,12 @@ maildir_memory_usage( store_t *gctx ATTR_UNUSED )
 	return 0;
 }
 
+static int
+maildir_fail_state( store_conf_t *gconf )
+{
+	return ((maildir_store_conf_t *)gconf)->failed;
+}
+
 static int
 maildir_parse_store( conffile_t *cfg, store_conf_t **storep )
 {
@@ -1698,4 +1705,5 @@ struct driver maildir_driver = {
 	maildir_cancel_cmds,
 	maildir_commit_cmds,
 	maildir_memory_usage,
+	maildir_fail_state,
 };

src/main.c

@@ -757,8 +757,10 @@ sync_chans( main_vars_t *mvars, int ent )
 		info( "Channel %s\n", mvars->chan->name );
 		mvars->skip = mvars->cben = 0;
 		for (t = 0; t < 2; t++) {
-			if (mvars->chan->stores[t]->failed != FAIL_TEMP) {
-				info( "Skipping due to failed %s store %s.\n", str_ms[t], mvars->chan->stores[t]->name );
+			int st = mvars->chan->stores[t]->driver->fail_state( mvars->chan->stores[t] );
+			if (st != FAIL_TEMP) {
+				info( "Skipping due to %sfailed %s store %s.\n",
+				      (st == FAIL_WAIT) ? "temporarily " : "", str_ms[t], mvars->chan->stores[t]->name );
 				mvars->skip = 1;
 			}
 		}