[filter] fix some glitches

src/keymap-default.json

@@ -16,7 +16,7 @@
     "keymap_def": {
         "default": {
             "x06": [
-                ";UPDATE lnav_view_filters SET enabled = 1 - enabled WHERE view_name = (SELECT name FROM lnav_view_stack LIMIT 1)"
+                ";UPDATE lnav_view_filters SET enabled = 1 - enabled WHERE view_name = (SELECT name FROM lnav_view_stack WHERE name in ('log', 'text') ORDER BY rowid DESC LIMIT 1)"
             ],
 
             "x0c": [

src/lnav_commands.cc

@@ -1192,9 +1192,17 @@ static string com_filter(exec_context &ec, string cmdline, vector<string> &args)
 
     if (args.empty()) {
         args.emplace_back("filter");
+
+        return "";
+    }
+
+    auto tc = *lnav_data.ld_view_stack.top();
+    auto tss = tc->get_sub_source();
+
+    if (!tss->tss_supports_filtering) {
+        retval = "error: view does not support filtering";
     }
     else if (args.size() > 1) {
-        textview_curses *tc = *lnav_data.ld_view_stack.top();
         text_sub_source *tss = tc->get_sub_source();
         filter_stack &fs = tss->get_filters();
         const char *errptr;

src/views_vtab.cc

@@ -472,6 +472,7 @@ CREATE TABLE lnav_view_filters (
                                            pattern.second);
         fs.add_filter(pf);
         tss->text_filters_changed();
+        tc.set_needs_update();
 
         return SQLITE_OK;
     }
@@ -490,6 +491,7 @@ CREATE TABLE lnav_view_filters (
                 break;
             }
         }
+        tc.set_needs_update();
 
         return SQLITE_OK;
     }
@@ -528,6 +530,7 @@ CREATE TABLE lnav_view_filters (
 
         *iter = pf;
         tss->text_filters_changed();
+        tc.set_needs_update();
 
         return SQLITE_OK;
     };