initialize xkb_rules.options to a null pointer

[Humm42]

Initializing it to an empty string had broken configuring xkbcommon
through the environment (XKB_DEFAULT_OPTIONS).

Fixes: ae31391 ("initialize rules and xkb_rules")

[sevz17]

Maybe it's worth initialize all xbk_rules with a NULL pointer, doesn't it?

[djpohly]

It was initialized to a NULL pointer before. Any fields not specified in an initializer (when an initializer is given) are by C standard initialized to the zero value of their type. (-pedantic might be overly so...)

[sevz17]

Well, with #245 there are no default flags, and we can leave rules and xkb_rules empty

[Humm42]

It was initialized to a NULL pointer before. Any fields not specified in an initializer (when an initializer is given) are by C standard initialized to the zero value of their type.

No, the initializer had been empty. You can’t do that. Other ways to initialize `xkb_rules` to all-zero: /* maybe here a comment about what you can put in there */ static const struct xkb_rule_names xkb_rules; /* static storage duration, thus zero-intialized */ static const struct xkb_rule_names xkb_rules = { /* can specify fields: rules, model etc. */ /* example : .options = "ctrl:nocaps", */ 0 };

[sevz17]

Thanks!