Fixed compiler warnings (A few of these was bugs)

client/mysqldump.c:
  Slave needs to be initialized with 0
dbug/dbug.c:
  Removed not existing function
plugin/semisync/semisync_master.cc:
  Fixed compiler warning
sql/opt_range.cc:
  thd needs to be set early as it's used in some error conditions.
sql/sql_table.cc:
  Changed to use uchar* to make array indexing portable
storage/innobase/handler/ha_innodb.cc:
  Removed not used variable
storage/maria/ma_delete.c:
  Fixed compiler warning
storage/maria/ma_write.c:
  Fixed compiler warning

client/mysqldump.c

@@ -4784,7 +4784,7 @@ static int add_slave_statements(void)
 
 static int do_show_slave_status(MYSQL *mysql_con)
 {
-  MYSQL_RES *slave;
+  MYSQL_RES *slave= 0;
   const char *comment_prefix=
     (opt_slave_data == MYSQL_OPT_SLAVE_DATA_COMMENTED_SQL) ? "-- " : "";
   if (mysql_query_with_error_report(mysql_con, &slave, "SHOW SLAVE STATUS"))

dbug/dbug.c

@@ -284,9 +284,6 @@ static int DoTrace(CODE_STATE *cs);
         /* Test to see if file is writable */
 #if defined(HAVE_ACCESS)
 static BOOLEAN Writable(const char *pathname);
-        /* Change file owner and group */
-static void ChangeOwner(CODE_STATE *cs, char *pathname);
-        /* Allocate memory for runtime support */
 #endif
 
 static void DoPrefix(CODE_STATE *cs, uint line);

plugin/semisync/semisync_master.cc

@@ -1049,10 +1049,11 @@ int ReplSemiSyncMaster::readSlaveReply(NET *net, uint32 server_id,
   ulong    log_file_len = 0;
   ulong    packet_len;
   int      result = -1;
-
   struct timespec start_ts;
   ulong trc_level = trace_level_;
 
+  LINT_INIT_STRUCT(start_ts);
+
   function_enter(kWho);
 
   assert((unsigned char)event_buf[1] == kPacketMagicNum);

sql/opt_range.cc

@@ -2001,7 +2001,7 @@ int QUICK_RANGE_SELECT::init_ror_merged_scan(bool reuse_handler)
 {
   handler *save_file= file, *org_file;
   my_bool org_key_read;
-  THD *thd;
+  THD *thd= head->in_use;
   DBUG_ENTER("QUICK_RANGE_SELECT::init_ror_merged_scan");
 
   in_ror_merged_scan= 1;
@@ -2023,7 +2023,6 @@ int QUICK_RANGE_SELECT::init_ror_merged_scan(bool reuse_handler)
     DBUG_RETURN(0);
   }
 
-  thd= head->in_use;
   if (!(file= head->file->clone(head->s->normalized_path.str, thd->mem_root)))
   {
     /* 

sql/sql_table.cc

@@ -1960,8 +1960,9 @@ bool mysql_rm_table(THD *thd,TABLE_LIST *tables, my_bool if_exists,
 static uint32 comment_length(THD *thd, uint32 comment_pos,
                              const char **comment_start)
 {
-  const char *query= thd->query();
-  const char *query_end= query + thd->query_length();
+  /* We use uchar * here to make array indexing portable */
+  const uchar *query= (uchar*) thd->query();
+  const uchar *query_end= (uchar*) query + thd->query_length();
   const uchar *const state_map= thd->charset()->state_map;
 
   for (; query < query_end; query++)
@@ -1975,12 +1976,12 @@ static uint32 comment_length(THD *thd, uint32 comment_pos,
       state_map[*query] != MY_LEX_LONG_COMMENT || query[1] != '*')
     return 0;
   
-  *comment_start= query;
+  *comment_start= (char*) query;
   
   for (query+= 3; query < query_end; query++)
   {
     if (query[-1] == '*' && query[0] == '/')
-      return query - *comment_start + 1;
+      return (char*) query - *comment_start + 1;
   }
   return 0;
 }

storage/innobase/handler/ha_innodb.cc

@@ -11703,7 +11703,7 @@ static MYSQL_SYSVAR_ULONG(read_ahead_threshold, srv_read_ahead_threshold,
   "trigger a readahead.",
   NULL, NULL, 56, 0, 64, 0);
 
-#ifdef UNIV_DEBUG
+#ifdef UNIV_DEBUG_never
 static MYSQL_SYSVAR_UINT(trx_rseg_n_slots_debug, trx_rseg_n_slots_debug,
   PLUGIN_VAR_RQCMDARG,
   "Debug flags for InnoDB to limit TRX_RSEG_N_SLOTS for trx_rsegf_undo_find_free()",

storage/maria/ma_delete.c

@@ -163,6 +163,8 @@ my_bool _ma_ck_delete(MARIA_HA *info, MARIA_KEY *key)
   MARIA_KEY org_key;
   DBUG_ENTER("_ma_ck_delete");
 
+  LINT_INIT_STRUCT(org_key);
+
   save_key_data= key->data;
   if (share->now_transactional)
   {

storage/maria/ma_write.c

@@ -478,6 +478,8 @@ static my_bool _ma_ck_write_btree_with_log(MARIA_HA *info, MARIA_KEY *key,
   my_bool transactional= share->now_transactional;
   DBUG_ENTER("_ma_ck_write_btree_with_log");
   
+  LINT_INIT_STRUCT(org_key);
+
   if (transactional)
   {
     /* Save original value as the key may change */