Merge "next" branch into "master".

diff --combined lib/svec.h
index 35de6d4,2a93139..d9bb8a7
--- 1/lib/svec.h
--- 2/lib/svec.h
+++ b/lib/svec.h
@@@ -19,10 -19,6 +19,10 @@@
  
  #include <stdbool.h>
  #include <stddef.h>
 + 
 +#ifdef  __cplusplus
 +extern "C" {
 +#endif
  
  struct svec {
      char **names;
@@@ -36,6 -32,7 +36,7 @@@ void svec_init(struct svec *)
  void svec_clone(struct svec *, const struct svec *);
  void svec_destroy(struct svec *);
  void svec_clear(struct svec *);
+ bool svec_is_empty(const struct svec *);
  void svec_add(struct svec *, const char *);
  void svec_add_nocopy(struct svec *, char *);
  void svec_del(struct svec *, const char *);
@@@ -70,9 -67,5 +71,9 @@@ void svec_pop_back(struct svec *)
            ? (NAME) = (SVEC)->names[INDEX], 1    \
            : 0);                                 \
           (INDEX)++)
 + 
 +#ifdef  __cplusplus
 +}
 +#endif
  
  #endif /* svec.h */

diff --combined lib/unixctl.h
index 24a9d8c,0b6cbf3..89199bb
--- 1/lib/unixctl.h
--- 2/lib/unixctl.h
+++ b/lib/unixctl.h
@@@ -16,10 -16,6 +16,10 @@@
  
  #ifndef UNIXCTL_H
  #define UNIXCTL_H 1
 + 
 +#ifdef  __cplusplus
 +extern "C" {
 +#endif
  
  /* Server for Unix domain socket control connection. */
  struct unixctl_server;
@@@ -39,14 -35,11 +39,15 @@@ const char *unixctl_client_target(cons
  
  /* Command registration. */
  struct unixctl_conn;
+ typedef void unixctl_cb_func(struct unixctl_conn *,
+                              const char *args, void *aux);
  void unixctl_command_register(const char *name,
-                               void (*cb)(struct unixctl_conn *,
-                                          const char *args));
+                               unixctl_cb_func *cb, void *aux);
  void unixctl_command_reply(struct unixctl_conn *, int code,
                             const char *body);
 + 
 +#ifdef  __cplusplus
 +}
 +#endif
  
  #endif /* unixctl.h */