Merge branch 'collectd-5.7' into collectd-5.8

diff --cc src/exec.c
Simple merge

diff --cc src/perl.c
Simple merge

diff --cc src/powerdns.c
index 0b08b29,da72ec8..c715807
--- 1/src/powerdns.c
--- 2/src/powerdns.c
+++ b/src/powerdns.c
@@@ -478,14 -478,11 +478,11 @@@ static int powerdns_get_data_dgram(list
    buffer[buffer_size - 1] = 0;
  
    *ret_buffer = buffer;
-   *ret_buffer_size = buffer_size;
- 
 -  return (0);
 +  return 0;
  } /* }}} int powerdns_get_data_dgram */
  
- static int powerdns_get_data_stream(list_item_t *item, /* {{{ */
-                                     char **ret_buffer,
-                                     size_t *ret_buffer_size) {
+ static int powerdns_get_data_stream(list_item_t *item, char **ret_buffer) {
+   /* {{{ */
    int sd;
    int status;
  
@@@ -550,26 -548,23 +548,23 @@@
    } /* while (42) */
    close(sd);
  
-   if (status < 0) {
+   if (status != 0) {
      sfree(buffer);
-   } else {
-     assert(status == 0);
-     *ret_buffer = buffer;
-     *ret_buffer_size = buffer_size;
+     return status;
    }
  
-   return status;
+   *ret_buffer = buffer;
+   return 0;
  } /* }}} int powerdns_get_data_stream */
  
- static int powerdns_get_data(list_item_t *item, char **ret_buffer,
-                              size_t *ret_buffer_size) {
+ static int powerdns_get_data(list_item_t *item, char **ret_buffer) {
    if (item->socktype == SOCK_DGRAM)
-     return powerdns_get_data_dgram(item, ret_buffer, ret_buffer_size);
 -    return (powerdns_get_data_dgram(item, ret_buffer));
++    return powerdns_get_data_dgram(item, ret_buffer);
    else if (item->socktype == SOCK_STREAM)
-     return powerdns_get_data_stream(item, ret_buffer, ret_buffer_size);
 -    return (powerdns_get_data_stream(item, ret_buffer));
++    return powerdns_get_data_stream(item, ret_buffer);
    else {
      ERROR("powerdns plugin: Unknown socket type: %i", (int)item->socktype);
 -    return (-1);
 +    return -1;
    }
  } /* int powerdns_get_data */
  
@@@ -592,13 -574,21 +574,21 @@@ static int powerdns_read_server(list_it
      item->command = strdup(SERVER_COMMAND);
    if (item->command == NULL) {
      ERROR("powerdns plugin: strdup failed.");
 -    return (-1);
 +    return -1;
    }
  
-   status = powerdns_get_data(item, &buffer, &buffer_size);
-   if (status != 0)
-     return -1;
+   char *buffer = NULL;
+   int status = powerdns_get_data(item, &buffer);
+   if (status != 0) {
+     ERROR("powerdns plugin: powerdns_get_data failed.");
 -    return (status);
++    return status;
+   }
+   if (buffer == NULL) {
+     return EINVAL;
+   }
  
+   const char *const *fields = default_server_fields;
+   int fields_num = default_server_fields_num;
    if (item->fields_num != 0) {
      fields = (const char *const *)item->fields;
      fields_num = item->fields_num;
@@@ -714,10 -701,10 +701,10 @@@ static int powerdns_read_recursor(list_
    }
    assert(item->command != NULL);
  
-   status = powerdns_get_data(item, &buffer, &buffer_size);
+   status = powerdns_get_data(item, &buffer);
    if (status != 0) {
      ERROR("powerdns plugin: powerdns_get_data failed.");
 -    return (-1);
 +    return -1;
    }
  
    keys_list = strdup(item->command);

diff --cc src/rrdtool.c
index 558b800,4fcbad4..cd275da
--- 1/src/rrdtool.c
--- 2/src/rrdtool.c
+++ b/src/rrdtool.c
@@@ -620,12 -624,11 +620,11 @@@ static int rrd_cache_insert(const char 
    if (cache == NULL) {
      pthread_mutex_unlock(&cache_lock);
      WARNING("rrdtool plugin: cache == NULL.");
 -    return (-1);
 +    return -1;
    }
  
-   c_avl_get(cache, filename, (void *)&rc);
- 
-   if (rc == NULL) {
+   int status = c_avl_get(cache, filename, (void *)&rc);
+   if ((status != 0) || (rc == NULL)) {
      rc = malloc(sizeof(*rc));
      if (rc == NULL) {
        pthread_mutex_unlock(&cache_lock);

diff --cc src/table.c
index 7cae3f7,eb18660..d798820
--- 1/src/table.c
--- 2/src/table.c
+++ b/src/table.c
@@@ -103,11 -105,16 +107,17 @@@ static void tbl_setup(tbl_t *tbl, char 
  } /* tbl_setup */
  
  static void tbl_clear(tbl_t *tbl) {
+   if (tbl == NULL) {
+     return;
+   }
+ 
    sfree(tbl->file);
    sfree(tbl->sep);
 +  sfree(tbl->plugin_name);
    sfree(tbl->instance);
  
+   /* (tbl->results == NULL) -> (tbl->results_num == 0) */
+   assert((tbl->results != NULL) || (tbl->results_num == 0));
    for (size_t i = 0; i < tbl->results_num; ++i)
      tbl_result_clear(tbl->results + i);
    sfree(tbl->results);