provide a proper getter callback for driver capabilities

that way driver_t contains only callbacks.

src/driver.h

@@ -147,7 +147,8 @@ typedef struct {
 #define LIST_PATH_MAYBE 4
 
 struct driver {
-	int flags;
+	/* Return driver capabilities. */
+	int (*get_caps)( store_t *ctx );
 
 	/* Parse configuration. */
 	int (*parse_store)( conffile_t *cfg, store_conf_t **storep );

src/drv_imap.c

@@ -3183,8 +3183,14 @@ imap_parse_store( conffile_t *cfg, store_conf_t **storep )
 	return 1;
 }
 
+static int
+imap_get_caps( store_t *gctx ATTR_UNUSED )
+{
+	return DRV_CRLF | DRV_VERBOSE;
+}
+
 struct driver imap_driver = {
-	DRV_CRLF | DRV_VERBOSE,
+	imap_get_caps,
 	imap_parse_store,
 	imap_cleanup,
 	imap_alloc_store,

src/drv_maildir.c

@@ -1865,8 +1865,14 @@ maildir_parse_store( conffile_t *cfg, store_conf_t **storep )
 	return 1;
 }
 
+static int
+maildir_get_caps( store_t *gctx ATTR_UNUSED )
+{
+	return 0; /* XXX DRV_CRLF? */
+}
+
 struct driver maildir_driver = {
-	0, /* XXX DRV_CRLF? */
+	maildir_get_caps,
 	maildir_parse_store,
 	maildir_cleanup_drv,
 	maildir_alloc_store,

src/main.c

@@ -810,7 +810,7 @@ sync_chans( main_vars_t *mvars, int ent )
 		if (mvars->skip)
 			goto next2;
 		mvars->state[M] = mvars->state[S] = ST_FRESH;
-		if (mvars->chan->stores[M]->driver->flags & mvars->chan->stores[S]->driver->flags & DRV_VERBOSE)
+		if (mvars->chan->stores[M]->driver->get_caps( 0 ) & mvars->chan->stores[S]->driver->get_caps( 0 ) & DRV_VERBOSE)
 			labels[M] = "M: ", labels[S] = "S: ";
 		else
 			labels[M] = labels[S] = "";

src/sync.c

@@ -407,8 +407,8 @@ msg_fetched( int sts, void *aux )
 
 		vars->msg->flags = vars->data.flags;
 
-		scr = (svars->drv[1-t]->flags / DRV_CRLF) & 1;
+		scr = (svars->drv[1-t]->get_caps( svars->ctx[1-t] ) / DRV_CRLF) & 1;
-		tcr = (svars->drv[t]->flags / DRV_CRLF) & 1;
+		tcr = (svars->drv[t]->get_caps( svars->ctx[t] ) / DRV_CRLF) & 1;
 		if (vars->srec || scr != tcr) {
 			if (!copy_msg_convert( scr, tcr, vars )) {
 				warn( "Warning: message %d from %s has incomplete header.\n",