Fix coverity issues (#14543)

* Fix coverity 383236: Resource leak

* Fix coverity 382915 : Logically dead code

* Fix coverity 379133 : Division or modulo by float zero

* Fix coverity 382783 : Copy into fixed size buffer

* Fix coverity 381151 : Missing unlock

* Fix coverity 381903 : Dereference after null check

aclk/aclk_rx_msgs.c

@@ -272,13 +272,12 @@ int create_node_instance_result(const char *msg, size_t msg_len)
         .live = 0,
         .queryable = 1,
         .session_id = aclk_session_newarch,
-        .node_id = res.node_id
+        .node_id = res.node_id,
+        .capabilities = NULL
     };
 
     RRDHOST *host = rrdhost_find_by_guid(res.machine_guid);
-    if (host) {
-        // not all host must have RRDHOST struct created for them
-        // if they never connected during runtime of agent
+    if (likely(host)) {
         if (host == localhost) {
             node_state_update.live = 1;
             node_state_update.hops = 0;
@@ -286,10 +285,9 @@ int create_node_instance_result(const char *msg, size_t msg_len)
             node_state_update.live = (!rrdhost_flag_check(host, RRDHOST_FLAG_ORPHAN));
             node_state_update.hops = host->system_info->hops;
         }
+        node_state_update.capabilities = aclk_get_node_instance_capas(host);
     }
 
-    node_state_update.capabilities = aclk_get_node_instance_capas(host);
-
     rrdhost_aclk_state_lock(localhost);
     node_state_update.claim_id = localhost->aclk_state.claimed_id;
     query->data.bin_payload.payload = generate_node_instance_connection(&query->data.bin_payload.size, &node_state_update);

collectors/apps.plugin/apps_plugin.c

@@ -5165,4 +5165,5 @@ int main(int argc, char **argv) {
 
         debug_log("done Loop No %zu", global_iterations_counter);
     }
+    netdata_mutex_unlock(&mutex);
 }

database/engine/cache.c

@@ -1764,7 +1764,7 @@ PGC *pgc_create(const char *name,
     cache->config.max_dirty_pages_per_call = max_dirty_pages_per_flush;
     cache->config.pgc_save_init_cb = pgc_save_init_cb;
     cache->config.pgc_save_dirty_cb = pgc_save_dirty_cb;
-    cache->config.max_pages_per_inline_eviction = (max_pages_per_inline_eviction < 2) ? 2 : max_pages_per_inline_eviction;
+    cache->config.max_pages_per_inline_eviction = max_pages_per_inline_eviction;
     cache->config.max_skip_pages_per_inline_eviction = (max_skip_pages_per_inline_eviction < 2) ? 2 : max_skip_pages_per_inline_eviction;
     cache->config.max_flushes_inline = (max_flushes_inline < 1) ? 1 : max_flushes_inline;
     cache->config.partitions = partitions < 1 ? (size_t)get_netdata_cpus() : partitions;

database/rrdcalc.c

@@ -95,7 +95,7 @@ static STRING *rrdcalc_replace_variables_with_rrdset_labels(const char *line, RR
             temp = buf;
         }
         else if (!strncmp(var, RRDCALC_VAR_LABEL, RRDCALC_VAR_LABEL_LEN)) {
-            char label_val[RRDCALC_VAR_MAX + 1] = { 0 };
+            char label_val[RRDCALC_VAR_MAX + RRDCALC_VAR_LABEL_LEN + 1] = { 0 };
             strcpy(label_val, var+RRDCALC_VAR_LABEL_LEN);
             label_val[i - RRDCALC_VAR_LABEL_LEN - 1] = '\0';
 

libnetdata/buffer/buffer.c

@@ -495,6 +495,7 @@ int buffer_unittest(void) {
     buffer_json_finalize(wb);
     errors += buffer_expect(wb, "{\n    \"hello\":\"world\",\n    \"alpha\":\"this: \\\" is a double quote\",\n    \"object1\":{\n        \"hello\":\"world\"\n    }\n}\n");
 
+    buffer_free(wb);
     return errors;
 }
 

web/api/queries/weights.c

@@ -741,6 +741,8 @@ static size_t spread_results_evenly(DICTIONARY *results, WEIGHTS_STATS *stats) {
     }
     dfe_done(t);
 
+    if(!dimensions) return 0;   // Coverity fix
+
     // sort the array with the values of all dimensions
     qsort(slots, dimensions, sizeof(NETDATA_DOUBLE), compare_netdata_doubles);