Fixed compiler warnings

Only warnings, should not have caused any bugs in old code

sql/opt_subselect.cc

@@ -2701,8 +2701,8 @@ void advance_sj_state(JOIN *join, table_map remaining_tables, uint idx,
     LooseScan detector in best_access_path)
   */
   remaining_tables &= ~new_join_tab->table->map;
-  table_map dups_producing_tables, prev_dups_producing_tables,
-            prev_sjm_lookup_tables;
+  table_map dups_producing_tables, UNINIT_VAR(prev_dups_producing_tables),
+    UNINIT_VAR(prev_sjm_lookup_tables);
 
   if (idx == join->const_tables)
     dups_producing_tables= 0;
@@ -2713,7 +2713,7 @@ void advance_sj_state(JOIN *join, table_map remaining_tables, uint idx,
   if ((emb_sj_nest= new_join_tab->emb_sj_nest))
     dups_producing_tables |= emb_sj_nest->sj_inner_tables;
 
-  Semi_join_strategy_picker **strategy, **prev_strategy;
+  Semi_join_strategy_picker **strategy, **prev_strategy= 0;
   if (idx == join->const_tables)
   {
     /* First table, initialize pickers */

sql/table.cc

@@ -1174,7 +1174,7 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
   char *keynames, *names, *comment_pos;
   const uchar *forminfo, *extra2;
   const uchar *frm_image_end = frm_image + frm_length;
-  uchar *record, *null_flags, *null_pos, *mysql57_vcol_null_pos;
+  uchar *record, *null_flags, *null_pos, *UNINIT_VAR(mysql57_vcol_null_pos);
   const uchar *disk_buff, *strpos;
   ulong pos, record_offset; 
   ulong rec_buff_length;
@@ -2407,6 +2407,11 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
         DBUG_ASSERT(field_nr < share->fields);
         reg_field= share->field[field_nr];
       }
+      else
+      {
+        reg_field= 0;
+        DBUG_ASSERT(name_length);
+      }
 
       vcol_screen_pos+= FRM_VCOL_NEW_HEADER_SIZE;
       vcol_info->set_vcol_type((enum_vcol_info_type) type);
@@ -7411,7 +7416,7 @@ int TABLE::update_virtual_fields(handler *h, enum_vcol_update_mode update_mode)
     DBUG_ASSERT(vcol_info);
     DBUG_ASSERT(vcol_info->expr);
 
-    bool update, swap_values= 0;
+    bool update= 0, swap_values= 0;
     switch (update_mode) {
     case VCOL_UPDATE_FOR_READ:
       update= !vcol_info->stored_in_db

storage/maria/ma_create.c

@@ -76,7 +76,7 @@ int maria_create(const char *name, enum data_file_type datafile_type,
   uint internal_table= flags & HA_CREATE_INTERNAL_TABLE;
   ulong reclength, real_reclength,min_pack_length;
   char kfilename[FN_REFLEN], klinkname[FN_REFLEN], *klinkname_ptr;
-  char dfilename[FN_REFLEN], dlinkname[FN_REFLEN], *dlinkname_ptr;
+  char dfilename[FN_REFLEN], dlinkname[FN_REFLEN], *dlinkname_ptr= 0;
   ulong pack_reclength;
   ulonglong tot_length,max_rows, tmp;
   enum en_fieldtype type;
@@ -1197,7 +1197,6 @@ int maria_create(const char *name, enum data_file_type datafile_type,
     {
       fn_format(dfilename,name,"", MARIA_NAME_DEXT,
                 MY_UNPACK_FILENAME | MY_APPEND_EXT);
-      dlinkname_ptr= NullS;
       create_flag= (flags & HA_CREATE_KEEP_FILES) ? 0 : MY_DELETE_OLD;
     }
     if ((dfile=
@@ -1251,8 +1250,6 @@ int maria_create(const char *name, enum data_file_type datafile_type,
   switch (errpos) {
   case 3:
     mysql_file_close(dfile, MYF(0));
-    /* fall through */
-  case 2:
     if (! (flags & HA_DONT_TOUCH_DATA))
     {
       mysql_file_delete(key_file_dfile, dfilename, MYF(sync_dir));