fix issues found by a static analyzer

cluster.c - stack buffer memory alignment
    The pointer 'buf' is cast to a more strictly aligned pointer type
evict.c - lazyfree_lazy_eviction, lazyfree_lazy_eviction always called
defrag.c - bug in dead code
server.c - casting was missing parenthesis
rax.c - indentation / newline suggested an 'else if' was intended

src/cluster.c

@@ -2140,7 +2140,7 @@ void clusterWriteHandler(aeEventLoop *el, int fd, void *privdata, int mask) {
  * full length of the packet. When a whole packet is in memory this function
  * will call the function to process the packet. And so forth. */
 void clusterReadHandler(aeEventLoop *el, int fd, void *privdata, int mask) {
-    char buf[sizeof(clusterMsg)];
+    clusterMsg buf[1];
     ssize_t nread;
     clusterMsg *hdr;
     clusterLink *link = (clusterLink*) privdata;
@@ -2517,7 +2517,8 @@ void clusterBroadcastPong(int target) {
  *
  * If link is NULL, then the message is broadcasted to the whole cluster. */
 void clusterSendPublish(clusterLink *link, robj *channel, robj *message) {
-    unsigned char buf[sizeof(clusterMsg)], *payload;
+    unsigned char *payload;
+    clusterMsg buf[1];
     clusterMsg *hdr = (clusterMsg*) buf;
     uint32_t totlen;
     uint32_t channel_len, message_len;
@@ -2537,7 +2538,7 @@ void clusterSendPublish(clusterLink *link, robj *channel, robj *message) {
 
     /* Try to use the local buffer if possible */
     if (totlen < sizeof(buf)) {
-        payload = buf;
+        payload = (unsigned char*)buf;
     } else {
         payload = zmalloc(totlen);
         memcpy(payload,hdr,sizeof(*hdr));
@@ -2554,7 +2555,7 @@ void clusterSendPublish(clusterLink *link, robj *channel, robj *message) {
 
     decrRefCount(channel);
     decrRefCount(message);
-    if (payload != buf) zfree(payload);
+    if (payload != (unsigned char*)buf) zfree(payload);
 }
 
 /* Send a FAIL message to all the nodes we are able to contact.
@@ -2563,7 +2564,7 @@ void clusterSendPublish(clusterLink *link, robj *channel, robj *message) {
  * we switch the node state to CLUSTER_NODE_FAIL and ask all the other
  * nodes to do the same ASAP. */
 void clusterSendFail(char *nodename) {
-    unsigned char buf[sizeof(clusterMsg)];
+    clusterMsg buf[1];
     clusterMsg *hdr = (clusterMsg*) buf;
 
     clusterBuildMessageHdr(hdr,CLUSTERMSG_TYPE_FAIL);
@@ -2575,7 +2576,7 @@ void clusterSendFail(char *nodename) {
  * slots configuration. The node name, slots bitmap, and configEpoch info
  * are included. */
 void clusterSendUpdate(clusterLink *link, clusterNode *node) {
-    unsigned char buf[sizeof(clusterMsg)];
+    clusterMsg buf[1];
     clusterMsg *hdr = (clusterMsg*) buf;
 
     if (link == NULL) return;
@@ -2583,7 +2584,7 @@ void clusterSendUpdate(clusterLink *link, clusterNode *node) {
     memcpy(hdr->data.update.nodecfg.nodename,node->name,CLUSTER_NAMELEN);
     hdr->data.update.nodecfg.configEpoch = htonu64(node->configEpoch);
     memcpy(hdr->data.update.nodecfg.slots,node->slots,sizeof(node->slots));
-    clusterSendMessage(link,buf,ntohl(hdr->totlen));
+    clusterSendMessage(link,(unsigned char*)buf,ntohl(hdr->totlen));
 }
 
 /* Send a MODULE message.
@@ -2591,7 +2592,8 @@ void clusterSendUpdate(clusterLink *link, clusterNode *node) {
  * If link is NULL, then the message is broadcasted to the whole cluster. */
 void clusterSendModule(clusterLink *link, uint64_t module_id, uint8_t type,
                        unsigned char *payload, uint32_t len) {
-    unsigned char buf[sizeof(clusterMsg)], *heapbuf;
+    unsigned char *heapbuf;
+    clusterMsg buf[1];
     clusterMsg *hdr = (clusterMsg*) buf;
     uint32_t totlen;
 
@@ -2606,7 +2608,7 @@ void clusterSendModule(clusterLink *link, uint64_t module_id, uint8_t type,
 
     /* Try to use the local buffer if possible */
     if (totlen < sizeof(buf)) {
-        heapbuf = buf;
+        heapbuf = (unsigned char*)buf;
     } else {
         heapbuf = zmalloc(totlen);
         memcpy(heapbuf,hdr,sizeof(*hdr));
@@ -2619,7 +2621,7 @@ void clusterSendModule(clusterLink *link, uint64_t module_id, uint8_t type,
     else
         clusterBroadcastMessage(heapbuf,totlen);
 
-    if (heapbuf != buf) zfree(heapbuf);
+    if (heapbuf != (unsigned char*)buf) zfree(heapbuf);
 }
 
 /* This function gets a cluster node ID string as target, the same way the nodes
@@ -2663,7 +2665,7 @@ void clusterPropagatePublish(robj *channel, robj *message) {
  * Note that we send the failover request to everybody, master and slave nodes,
  * but only the masters are supposed to reply to our query. */
 void clusterRequestFailoverAuth(void) {
-    unsigned char buf[sizeof(clusterMsg)];
+    clusterMsg buf[1];
     clusterMsg *hdr = (clusterMsg*) buf;
     uint32_t totlen;
 
@@ -2679,7 +2681,7 @@ void clusterRequestFailoverAuth(void) {
 
 /* Send a FAILOVER_AUTH_ACK message to the specified node. */
 void clusterSendFailoverAuth(clusterNode *node) {
-    unsigned char buf[sizeof(clusterMsg)];
+    clusterMsg buf[1];
     clusterMsg *hdr = (clusterMsg*) buf;
     uint32_t totlen;
 
@@ -2687,12 +2689,12 @@ void clusterSendFailoverAuth(clusterNode *node) {
     clusterBuildMessageHdr(hdr,CLUSTERMSG_TYPE_FAILOVER_AUTH_ACK);
     totlen = sizeof(clusterMsg)-sizeof(union clusterMsgData);
     hdr->totlen = htonl(totlen);
-    clusterSendMessage(node->link,buf,totlen);
+    clusterSendMessage(node->link,(unsigned char*)buf,totlen);
 }
 
 /* Send a MFSTART message to the specified node. */
 void clusterSendMFStart(clusterNode *node) {
-    unsigned char buf[sizeof(clusterMsg)];
+    clusterMsg buf[1];
     clusterMsg *hdr = (clusterMsg*) buf;
     uint32_t totlen;
 
@@ -2700,7 +2702,7 @@ void clusterSendMFStart(clusterNode *node) {
     clusterBuildMessageHdr(hdr,CLUSTERMSG_TYPE_MFSTART);
     totlen = sizeof(clusterMsg)-sizeof(union clusterMsgData);
     hdr->totlen = htonl(totlen);
-    clusterSendMessage(node->link,buf,totlen);
+    clusterSendMessage(node->link,(unsigned char*)buf,totlen);
 }
 
 /* Vote for the node asking for our vote if there are the conditions. */

src/defrag.c

@@ -374,7 +374,7 @@ long activeDefragSdsListAndDict(list *l, dict *d, int dict_val_type) {
             if ((newele = activeDefragStringOb(ele, &defragged)))
                 de->v.val = newele, defragged++;
         } else if (dict_val_type == DEFRAG_SDS_DICT_VAL_VOID_PTR) {
-            void *newptr, *ptr = ln->value;
+            void *newptr, *ptr = dictGetVal(de);
             if ((newptr = activeDefragAlloc(ptr)))
                 ln->value = newptr, defragged++;
         }

src/evict.c

@@ -444,6 +444,7 @@ int getMaxmemoryState(size_t *total, size_t *logical, size_t *tofree, float *lev
  * Otehrwise if we are over the memory limit, but not enough memory
  * was freed to return back under the limit, the function returns C_ERR. */
 int freeMemoryIfNeeded(void) {
+    int keys_freed = 0;
     /* By default replicas should ignore maxmemory
      * and just be masters exact copies. */
     if (server.masterhost && server.repl_slave_ignore_maxmemory) return C_OK;
@@ -467,7 +468,7 @@ int freeMemoryIfNeeded(void) {
 
     latencyStartMonitor(latency);
     while (mem_freed < mem_tofree) {
-        int j, k, i, keys_freed = 0;
+        int j, k, i;
         static unsigned int next_db = 0;
         sds bestkey = NULL;
         int bestdbid;
@@ -598,9 +599,7 @@ int freeMemoryIfNeeded(void) {
                     mem_freed = mem_tofree;
                 }
             }
-        }
+        } else {
-
-        if (!keys_freed) {
             latencyEndMonitor(latency);
             latencyAddSampleIfNeeded("eviction-cycle",latency);
             goto cant_free; /* nothing to free... */

src/rax.c

@@ -1791,7 +1791,8 @@ int raxCompare(raxIterator *iter, const char *op, unsigned char *key, size_t key
         if (eq && key_len == iter->key_len) return 1;
         else if (lt) return iter->key_len < key_len;
         else if (gt) return iter->key_len > key_len;
-    } if (cmp > 0) {
+        return 0;
+    } else if (cmp > 0) {
         return gt ? 1 : 0;
     } else /* (cmp < 0) */ {
         return lt ? 1 : 0;

src/server.c

@@ -4278,7 +4278,7 @@ sds genRedisInfoString(char *section) {
             if (server.repl_state != REPL_STATE_CONNECTED) {
                 info = sdscatprintf(info,
                     "master_link_down_since_seconds:%jd\r\n",
-                    (intmax_t)server.unixtime-server.repl_down_since);
+                    (intmax_t)(server.unixtime-server.repl_down_since));
             }
             info = sdscatprintf(info,
                 "slave_priority:%d\r\n"