add noop action

extra/swayimgrc.5

@@ -192,6 +192,7 @@ in the key name.
 .PP
 Valid actions:
 .IP "\fBnone\fR: can be used for removing built-in action;"
+.IP "\fBnoop\fR: can be used for handle keys silently;"
 .IP "\fBhelp\fR: show/hide help;"
 .IP "\fBfirst_file\fR: jump to the first file;"
 .IP "\fBlast_file\fR: jump to the last file;"

src/action.c

@@ -12,6 +12,7 @@
 /** Action names. */
 static const char* action_names[] = {
     [action_none] = "none",
+    [action_noop] = "noop",
     [action_help] = "help",
     [action_first_file] = "first_file",
     [action_last_file] = "last_file",

src/action.h

@@ -10,6 +10,7 @@
 /** Supported actions. */
 enum action_type {
     action_none,
+    action_noop,
     action_help,
     action_first_file,
     action_last_file,

src/viewer.c

@@ -752,6 +752,7 @@ void viewer_on_keyboard(xkb_keysym_t key, uint8_t mods)
     while (action->type != action_none) {
         switch (action->type) {
             case action_none:
+            case action_noop:
                 break;
             case action_help:
                 switch_help();