command: make "add <property> 0" not change the value

The value 0 was treated specially, and effectively forced the increment
to 1. Interestingly, passing 0 or no value also does not include the
scale (from touchpads etc.), but this is probably an accidental behavior
that was never intentionally added.

Simplify it and make the default increment 1. 0 now means what it
should: the value will not be changed. This is not particularly useful,
but on the other hand there is no need for surprising and unintuitive
semantics.

OARG_CYCLEDIR() failed to apply the default value, because
m_option_type_cycle_dir was missing a copy handler - add this too.

1 files changed, 2 insertions, 4 deletions

diff --git a/player/command.c b/player/command.c
index 8514be98f7..19f725ba3a 100644
--- a/player/command.c
+++ b/player/command.c
@@ -4286,13 +4286,11 @@ int run_command(struct MPContext *mpctx, struct mp_cmd *cmd, struct mpv_node *re
     case MP_CMD_ADD:
     case MP_CMD_CYCLE:
     {
+        char *property = cmd->args[0].v.s;
         struct m_property_switch_arg s = {
-            .inc = 1,
+            .inc = cmd->args[1].v.d * cmd->scale,
             .wrap = cmd->id == MP_CMD_CYCLE,
         };
-        if (cmd->args[1].v.d)
-            s.inc = cmd->args[1].v.d * cmd->scale;
-        char *property = cmd->args[0].v.s;
         if (cmd->repeated && !check_property_autorepeat(property, mpctx)) {
             MP_VERBOSE(mpctx, "Dropping command '%.*s' from auto-repeated key.\n",
                        BSTR_P(cmd->original));