test/sr: Free SRVs before replacing them in test_sr_setup_srv()

Stop leaking parts of the shared random state in the shared-random unit
tests. The previous fix in 29599 was incomplete.

Fixes bug 29706; bugfix on 0.2.9.1-alpha.

changes/bug29706_minimal

+  o Minor bugfixes (memory management, testing):
+    - Stop leaking parts of the shared random state in the shared-random unit
+      tests. The previous fix in 29599 was incomplete.
+      Fixes bug 29706; bugfix on 0.2.9.1-alpha.

src/or/shared_random_state.c

@@ -1007,7 +1007,7 @@ state_query(sr_state_action_t action, sr_state_object_t obj_type,
 
 /* Delete the current SRV value from the state freeing it and the value is set
  * to NULL meaning empty. */
-static void
+STATIC void
 state_del_current_srv(void)
 {
   state_query(SR_STATE_ACTION_DEL, SR_STATE_OBJ_CURSRV, NULL, NULL);
@@ -1015,7 +1015,7 @@ state_del_current_srv(void)
 
 /* Delete the previous SRV value from the state freeing it and the value is
  * set to NULL meaning empty. */
-static void
+STATIC void
 state_del_previous_srv(void)
 {
   state_query(SR_STATE_ACTION_DEL, SR_STATE_OBJ_PREVSRV, NULL, NULL);

src/or/shared_random_state.h

@@ -140,6 +140,8 @@ STATIC int is_phase_transition(sr_phase_t next_phase);
 
 STATIC void set_sr_phase(sr_phase_t phase);
 STATIC sr_state_t *get_sr_state(void);
+STATIC void state_del_previous_srv(void);
+STATIC void state_del_current_srv(void);
 
 #endif /* TOR_UNIT_TESTS */
 

src/test/test_shared_random.c

@@ -461,6 +461,8 @@ test_sr_setup_srv(int also_current)
          "ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ",
          sizeof(srv->value));
 
+ /* sr_state_set_previous_srv() does not free() the old previous srv. */
+ state_del_previous_srv();
  sr_state_set_previous_srv(srv);
 
  if (also_current) {
@@ -470,6 +472,8 @@ test_sr_setup_srv(int also_current)
           "NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN",
           sizeof(srv->value));
 
+   /* sr_state_set_previous_srv() does not free() the old current srv. */
+   state_del_current_srv();
    sr_state_set_current_srv(srv);
  }
 }