Squash a leak in LRU caches

env.cpp

@@ -1005,7 +1005,7 @@ static int try_remove( env_node_t *n,
 			has_changed = 1;
 		}
         
-        n->env.erase(result);
+		n->env.erase(result);
 		delete v;
 		return 1;
 	}

history.cpp

@@ -624,7 +624,9 @@ void history_t::save_internal()
                     break;
                 }
             }
-
+            
+            /* Make sure we clear all nodes, since this doesn't happen automatically */
+            lru.evict_all_nodes();
 
 			if( fclose( out ) || !ok )
 			{

iothread.cpp

@@ -142,7 +142,7 @@ int iothread_perform_base(int (*handler)(void *), void (*completionCallback)(voi
 	iothread_init();
 	
 	/* Create and initialize a request. */
-	struct ThreadedRequest_t *req = (struct ThreadedRequest_t *)malloc(sizeof *req);
+	struct ThreadedRequest_t *req = new ThreadedRequest_t();
 	req->next = NULL;
 	req->handler = handler;
 	req->completionCallback = completionCallback;
@@ -186,10 +186,12 @@ void iothread_service_completion(void) {
 	s_active_thread_count -= 1;
 	
 	/* Handle the request */
-	if (req && req->completionCallback) {
-		req->completionCallback(req->context, req->handlerResult);
-	}
-	
+    if (req) {
+        if (req->completionCallback) 
+            req->completionCallback(req->context, req->handlerResult);
+        delete req;
+    }
+    
 	/* Maybe spawn another thread, if there's more work to be done. */
 	VOMIT_ON_FAILURE(pthread_mutex_lock(&s_request_queue_lock));
 	iothread_spawn_if_needed();

lru.h

@@ -101,6 +101,9 @@ class lru_cache_t {
         mouth.prev = mouth.next = &mouth;
     }
     
+    /** Note that we do not define a destructor. We cannot evict all nodes (even though they typically need to be deleted by their creator). */
+
+    
     /** Returns the node for a given key, or NULL */
     node_type_t *get_node(const wcstring &key) {
         node_type_t *result = NULL;