MDEV-13459 Warnings, when compiling with gcc-7.x

mostly caused by -Wimplicit-fallthrough

53 files changed, 170 insertions, 124 deletions

diff --git a/client/mysql.cc b/client/mysql.cc
index 9c76e30d96f..2a56caf23ef 100644
--- a/client/mysql.cc
+++ b/client/mysql.cc
@@ -1080,7 +1080,7 @@ static ulong start_timer(void);
 static void end_timer(ulong start_time,char *buff);
 static void mysql_end_timer(ulong start_time,char *buff);
 static void nice_time(double sec,char *buff,bool part_second);
-extern "C" sig_handler mysql_end(int sig);
+extern "C" sig_handler mysql_end(int sig) __attribute__ ((noreturn));
 extern "C" sig_handler handle_sigint(int sig);
 #if defined(HAVE_TERMIOS_H) && defined(GWINSZ_IN_SYS_IOCTL)
 static sig_handler window_resize(int sig);
diff --git a/client/mysqldump.c b/client/mysqldump.c
index 2e3270a2fed..4e611ed5cb2 100644
--- a/client/mysqldump.c
+++ b/client/mysqldump.c
@@ -2012,6 +2012,7 @@ static void print_xml_comment(FILE *xml_file, size_t len,
     case '-':
       if (*(comment_string + 1) == '-')         /* Only one hyphen allowed. */
         break;
+      /* fall through */
     default:
       fputc(*comment_string, xml_file);
       break;
diff --git a/extra/my_print_defaults.c b/extra/my_print_defaults.c
index 7558d6d00ae..4690b29e8a5 100644
--- a/extra/my_print_defaults.c
+++ b/extra/my_print_defaults.c
@@ -97,12 +97,16 @@ static struct my_option my_long_options[] =
 };
 
 
-static void usage(my_bool version)
+static void version()
 {
-  printf("%s  Ver 1.6 for %s at %s\n",my_progname,SYSTEM_TYPE,
-	 MACHINE_TYPE);
-  if (version)
-    return;
+  printf("%s  Ver 1.6 for %s at %s\n",my_progname,SYSTEM_TYPE, MACHINE_TYPE);
+}
+
+
+static void usage() __attribute__ ((noreturn));
+static void usage()
+{
+  version();
   puts("This software comes with ABSOLUTELY NO WARRANTY. This is free software,\nand you are welcome to modify and redistribute it under the GPL license\n");
   puts("Prints all arguments that is give to some program using the default files");
   printf("Usage: %s [OPTIONS] [groups]\n", my_progname);
@@ -126,12 +130,13 @@ get_one_option(int optid, const struct my_option *opt __attribute__((unused)),
       exit(0);
     case 'I':
     case '?':
-      usage(0);
+      usage();
     case 'v':
       verbose++;
       break;
     case 'V':
-      usage(1);
+      version();
+      /* fall through */
     case '#':
       DBUG_PUSH(argument ? argument : default_dbug_option);
       break;
@@ -179,7 +184,7 @@ int main(int argc, char **argv)
     nargs+= array_elements(mysqld_groups);
 
   if (nargs < 2)
-    usage(0);
+    usage();
 
   load_default_groups=(char**) my_malloc(nargs*sizeof(char*), MYF(MY_WME));
   if (!load_default_groups)
diff --git a/extra/replace.c b/extra/replace.c
index 56cf02f2002..2ad4979c09e 100644
--- a/extra/replace.c
+++ b/extra/replace.c
@@ -174,6 +174,7 @@ register char **argv[];
 	break;
       case 'V':
 	version=1;
+        /* fall through */
       case 'I':
       case '?':
 	help=1;					/* Help text written */
diff --git a/mysys/my_new.cc b/mysys/my_new.cc
index 4266452da43..a401ccff135 100644
--- a/mysys/my_new.cc
+++ b/mysys/my_new.cc
@@ -47,6 +47,11 @@ void* operator new[](std::size_t sz, const std::nothrow_t&) throw()
   return (void *) my_malloc (sz ? sz : 1, MYF(0));
 }
 
+void operator delete (void *ptr, std::size_t)
+{
+  my_free(ptr);
+}
+
 void operator delete (void *ptr)
 {
   my_free(ptr);
@@ -57,6 +62,11 @@ void operator delete[] (void *ptr) throw ()
   my_free(ptr);
 }
 
+void operator delete[] (void *ptr, std::size_t) throw ()
+{
+  my_free(ptr);
+}
+
 void operator delete(void* ptr, const std::nothrow_t&) throw()
 {
   my_free(ptr);
diff --git a/plugin/handler_socket/CMakeLists.txt b/plugin/handler_socket/CMakeLists.txt
index 358139eda1e..a0cac0015d0 100644
--- a/plugin/handler_socket/CMakeLists.txt
+++ b/plugin/handler_socket/CMakeLists.txt
@@ -10,6 +10,12 @@ IF(CMAKE_COMPILER_IS_GNUCXX)
   STRING(REPLACE "-fno-implicit-templates" "" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
 ENDIF()
 
+include(CheckCXXCompilerFlag)
+check_cxx_compiler_flag(" -Wdeprecated-declarations" HAVE_CXX_WDEPRECATED_DECLARATIONS)
+IF (HAVE_CXX_WDEPRECATED_DECLARATIONS)
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-deprecated-declarations")
+ENDIF()
+
 INCLUDE_DIRECTORIES(libhsclient)
 
 # Handlersocket client library. We do not distribute it, 
diff --git a/sql-common/client.c b/sql-common/client.c
index e0412fca6bc..7d92f71d69f 100644
--- a/sql-common/client.c
+++ b/sql-common/client.c
@@ -1276,6 +1276,7 @@ void mysql_read_default_options(struct st_mysql_options *options,
 	  break;
         case OPT_pipe:
           options->protocol = MYSQL_PROTOCOL_PIPE;
+          break;
         case OPT_connect_timeout: 
 	case OPT_timeout:
 	  if (opt_arg)
diff --git a/sql/events.cc b/sql/events.cc
index 763c75e77b0..008b6223702 100644
--- a/sql/events.cc
+++ b/sql/events.cc
@@ -185,8 +185,8 @@ common_1_lev_code:
 
     expr= tmp_expr - (tmp_expr/60)*60;
     /* the code after the switch will finish */
-  }
     break;
+  }
   case INTERVAL_HOUR_SECOND:
   {
     ulonglong tmp_expr= expr;
@@ -202,8 +202,8 @@ common_1_lev_code:
 
     expr= tmp_expr - (tmp_expr/60)*60;
     /* the code after the switch will finish */
-  }
     break;
+  }
   case INTERVAL_DAY_SECOND:
   {
     ulonglong tmp_expr= expr;
@@ -225,8 +225,8 @@ common_1_lev_code:
 
     expr= tmp_expr - (tmp_expr/60)*60;
     /* the code after the switch will finish */
-  }
     break;
+  }
   case INTERVAL_DAY_MICROSECOND:
   case INTERVAL_HOUR_MICROSECOND:
   case INTERVAL_MINUTE_MICROSECOND:
@@ -240,6 +240,8 @@ common_1_lev_code:
     break;
   case INTERVAL_WEEK:
     expr/= 7;
+    close_quote= FALSE;
+    break;
   default:
     close_quote= FALSE;
     break;
diff --git a/sql/field.cc b/sql/field.cc
index 716d522a196..a2e0caaa50d 100644
--- a/sql/field.cc
+++ b/sql/field.cc
@@ -9218,7 +9218,7 @@ bool Create_field::init(THD *thd, char *fld_name, enum_field_types fld_type,
   case MYSQL_TYPE_DATE:
     /* We don't support creation of MYSQL_TYPE_DATE anymore */
     sql_type= MYSQL_TYPE_NEWDATE;
-    /* fall trough */
+    /* fall through */
   case MYSQL_TYPE_NEWDATE:
     length= MAX_DATE_WIDTH;
     break;
diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc
index e048dbad5e6..b2c2140d4dc 100644
--- a/sql/ha_partition.cc
+++ b/sql/ha_partition.cc
@@ -7331,6 +7331,7 @@ void ha_partition::print_error(int error, myf errflag)
         m_err_rec= NULL;
         DBUG_VOID_RETURN;
       }
+      /* fall through */
     default:
       {
         if (!(thd->lex->alter_info.flags & ALTER_TRUNCATE_PARTITION))
diff --git a/sql/item.cc b/sql/item.cc
index a8913e97fe9..3c633ddc9ca 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -6004,7 +6004,7 @@ Field *Item::tmp_table_field_from_field_type(TABLE *table, bool fixed_length)
                               collation.collation);
       break;
     }
-    /* Fall through to make_string_field() */
+    /* fall through */
   case MYSQL_TYPE_ENUM:
   case MYSQL_TYPE_SET:
   case MYSQL_TYPE_VAR_STRING:
diff --git a/sql/item_func.cc b/sql/item_func.cc
index cfccd66ea8a..00006a25a8d 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -863,6 +863,7 @@ void Item_func_num1::fix_length_and_dec()
     break;
   case TIME_RESULT:
     cached_result_type= DECIMAL_RESULT;
+    /* fall through */
   case DECIMAL_RESULT:
     decimals= args[0]->decimal_scale(); // Do not preserve NOT_FIXED_DEC
     max_length= args[0]->max_length;
@@ -2038,6 +2039,7 @@ my_decimal *Item_func_mod::decimal_op(my_decimal *decimal_value)
     return decimal_value;
   case E_DEC_DIV_ZERO:
     signal_divide_by_null();
+    /* fall through */
   default:
     null_value= 1;
     return 0;
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 756ab5152ca..939e518e386 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -4430,7 +4430,7 @@ bool Item_dyncol_get::get_date(MYSQL_TIME *ltime, ulonglong fuzzy_date)
     goto null;
   case DYN_COL_INT:
     signed_value= 1;                                  // For error message
-    /* fall_trough */
+    /* fall through */
   case DYN_COL_UINT:
     if (signed_value || val.x.ulong_value <= LONGLONG_MAX)
     {
@@ -4443,7 +4443,7 @@ bool Item_dyncol_get::get_date(MYSQL_TIME *ltime, ulonglong fuzzy_date)
     }
     /* let double_to_datetime_with_warn() issue the warning message */
     val.x.double_value= static_cast<double>(ULONGLONG_MAX);
-    /* fall_trough */
+    /* fall through */
   case DYN_COL_DOUBLE:
     if (double_to_datetime_with_warn(val.x.double_value, ltime, fuzzy_date,
                                      0 /* TODO */))
diff --git a/sql/log.cc b/sql/log.cc
index f8c256e645f..5b4ba87ef52 100644
--- a/sql/log.cc
+++ b/sql/log.cc
@@ -7261,8 +7261,10 @@ void TC_LOG_MMAP::close()
     mysql_cond_destroy(&COND_pool);
     mysql_cond_destroy(&COND_active);
     mysql_cond_destroy(&COND_queue_busy);
+    /* fall through */
   case 5:
     data[0]='A'; // garble the first (signature) byte, in case mysql_file_delete fails
+    /* fall through */
   case 4:
     for (i=0; i < npages; i++)
     {
@@ -7271,10 +7273,13 @@ void TC_LOG_MMAP::close()
       mysql_mutex_destroy(&pages[i].lock);
       mysql_cond_destroy(&pages[i].cond);
     }
+    /* fall through */
   case 3:
     my_free(pages);
+    /* fall through */
   case 2:
     my_munmap((char*)data, (size_t)file_length);
+    /* fall through */
   case 1:
     mysql_file_close(fd, MYF(0));
   }
diff --git a/sql/log_event.cc b/sql/log_event.cc
index d5b5b5a4870..18e4cfbf187 100644
--- a/sql/log_event.cc
+++ b/sql/log_event.cc
@@ -6437,21 +6437,6 @@ User_var_log_event(const char* buf, uint event_len,
       we keep the flags set to UNDEF_F.
     */
     uint bytes_read= ((val + val_len) - start);
-#ifndef DBUG_OFF
-    bool old_pre_checksum_fd= description_event->is_version_before_checksum(
-        &description_event->server_version_split);
-#endif
-    DBUG_ASSERT((bytes_read == data_written -
-                 (old_pre_checksum_fd ||
-                  (description_event->checksum_alg ==
-                   BINLOG_CHECKSUM_ALG_OFF)) ?
-                 0 : BINLOG_CHECKSUM_LEN)
-                ||
-                (bytes_read == data_written -1 -
-                 (old_pre_checksum_fd ||
-                  (description_event->checksum_alg ==
-                   BINLOG_CHECKSUM_ALG_OFF)) ?
-                 0 : BINLOG_CHECKSUM_LEN));
     if ((data_written - bytes_read) > 0)
     {
       flags= (uint) *(buf + UV_VAL_IS_NULL + UV_VAL_TYPE_SIZE +
diff --git a/sql/opt_sum.cc b/sql/opt_sum.cc
index 1a8c6be5f41..f717be5ba3f 100644
--- a/sql/opt_sum.cc
+++ b/sql/opt_sum.cc
@@ -1047,6 +1047,7 @@ static int maxmin_in_range(bool max_fl, Field* field, COND *cond)
   case Item_func::LT_FUNC:
   case Item_func::LE_FUNC:
     less_fl= 1;
+    /* fall through */
   case Item_func::GT_FUNC:
   case Item_func::GE_FUNC:
   {
diff --git a/sql/partition_info.cc b/sql/partition_info.cc
index d8b901701cb..512bf296135 100644
--- a/sql/partition_info.cc
+++ b/sql/partition_info.cc
@@ -34,8 +34,6 @@
 
 partition_info *partition_info::get_clone()
 {
-  if (!this)
-    return 0;
   List_iterator<partition_element> part_it(partitions);
   partition_element *part;
   partition_info *clone= new partition_info();
diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index 69364eaa43f..14a57914560 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -139,7 +139,7 @@ sp_get_item_value(THD *thd, Item *item, String *str)
   case DECIMAL_RESULT:
     if (item->field_type() != MYSQL_TYPE_BIT)
       return item->val_str(str);
-    else {/* Bit type is handled as binary string */}
+    /* fall through */
   case STRING_RESULT:
     {
       String *result= item->val_str(str);
diff --git a/sql/sql_admin.cc b/sql/sql_admin.cc
index 55effcd7002..7cddf50a896 100644
--- a/sql/sql_admin.cc
+++ b/sql/sql_admin.cc
@@ -54,7 +54,6 @@ static bool admin_recreate_table(THD *thd, TABLE_LIST *table_list)
   if (thd->stmt_da->is_ok())
     thd->stmt_da->reset_diagnostics_area();
   table_list->table= NULL;
-  result_code= result_code ? HA_ADMIN_FAILED : HA_ADMIN_OK;
   DBUG_RETURN(result_code);
 }
 
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 6611fd43876..6f94f1fbe63 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -1147,12 +1147,14 @@ static int lex_one_token(YYSTYPE *yylval, THD *thd)
 	state= MY_LEX_HEX_NUMBER;
 	break;
       }
+      /* fall through */
     case MY_LEX_IDENT_OR_BIN:
       if (lip->yyPeek() == '\'')
       {                                 // Found b'bin-number'
         state= MY_LEX_BIN_NUMBER;
         break;
       }
+      /* fall through */
     case MY_LEX_IDENT:
       const char *start;
 #if defined(USE_MB) && defined(USE_MB_IDENT)
@@ -1499,7 +1501,7 @@ static int lex_one_token(YYSTYPE *yylval, THD *thd)
 	state= MY_LEX_USER_VARIABLE_DELIMITER;
 	break;
       }
-      /* " used for strings */
+      /* fall through */ /* " used for strings */
     case MY_LEX_STRING:			// Incomplete text string
       if (!(yylval->lex_str.str = get_text(lip, 1, 1)))
       {
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index ba0520de4bb..d003a13ae09 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -2481,7 +2481,7 @@ case SQLCOM_PREPARE:
 #ifdef WITH_PARTITION_STORAGE_ENGINE
     {
       partition_info *part_info= thd->lex->part_info;
-      if (part_info && !(part_info= thd->lex->part_info->get_clone()))
+      if (part_info && !(part_info= part_info->get_clone()))
       {
         res= -1;
         goto end_with_restore_list;
@@ -2850,8 +2850,8 @@ end_with_restore_list:
     /* mysql_update return 2 if we need to switch to multi-update */
     if (up_result != 2)
       break;
-    /* Fall through */
   }
+  /* fall through */
   case SQLCOM_UPDATE_MULTI:
   {
     DBUG_ASSERT(first_table == all_tables && first_table != 0);
@@ -2961,6 +2961,7 @@ end_with_restore_list:
       DBUG_PRINT("debug", ("Just after generate_incident()"));
     }
 #endif
+    /* fall through */
   case SQLCOM_INSERT:
   {
     DBUG_ASSERT(first_table == all_tables && first_table != 0);
@@ -3698,6 +3699,7 @@ end_with_restore_list:
       initialize this variable because RESET shares the same code as FLUSH
     */
     lex->no_write_to_binlog= 1;
+    /* fall through */
   case SQLCOM_FLUSH:
   {
     int write_to_binlog;
diff --git a/sql/sql_partition.cc b/sql/sql_partition.cc
index 0d9f6e6a1f5..bf34d328dc5 100644
--- a/sql/sql_partition.cc
+++ b/sql/sql_partition.cc
@@ -4640,7 +4640,7 @@ uint prep_alter_part_table(THD *thd, TABLE *table, Alter_info *alter_info,
   thd->work_part_info= thd->lex->part_info;
 
   if (thd->work_part_info &&
-      !(thd->work_part_info= thd->lex->part_info->get_clone()))
+      !(thd->work_part_info= thd->work_part_info->get_clone()))
     DBUG_RETURN(TRUE);
 
   /* ALTER_ADMIN_PARTITION is handled in mysql_admin_table */
diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
index 9eecd6a1345..d1e855e272e 100644
--- a/sql/sql_plugin.cc
+++ b/sql/sql_plugin.cc
@@ -1078,42 +1078,42 @@ static bool plugin_add(MEM_ROOT *tmp_root,
     if (!name->str && plugin_find_internal(&tmp.name, MYSQL_ANY_PLUGIN))
       continue; // already installed
 
-      struct st_plugin_int *tmp_plugin_ptr;
-      if (*(int*)plugin->info <
-          min_plugin_info_interface_version[plugin->type] ||
-          ((*(int*)plugin->info) >> 8) >
-          (cur_plugin_info_interface_version[plugin->type] >> 8))
-      {
-        char buf[256];
-        strxnmov(buf, sizeof(buf) - 1, "API version for ",
-                 plugin_type_names[plugin->type].str,
-                 " plugin ", tmp.name.str,
-                 " not supported by this version of the server", NullS);
-        report_error(report, ER_CANT_OPEN_LIBRARY, dl->str, ENOEXEC, buf);
-        goto err;
-      }
-      if (plugin_maturity_map[plugin->maturity] < plugin_maturity)
-      {
-        char buf[256];
-        strxnmov(buf, sizeof(buf) - 1, "Loading of ",
-                 plugin_maturity_names[plugin->maturity],
-                 " plugin ", tmp.name.str,
-                 " is prohibited by --plugin-maturity=",
-                 plugin_maturity_names[plugin_maturity],
-                 NullS);
-        report_error(report, ER_CANT_OPEN_LIBRARY, dl->str, EPERM, buf);
-        goto err;
-      }
-      tmp.plugin= plugin;
-      tmp.ref_count= 0;
-      tmp.state= PLUGIN_IS_UNINITIALIZED;
-      tmp.load_option= PLUGIN_ON;
+    struct st_plugin_int *tmp_plugin_ptr;
+    if (*(int*)plugin->info <
+        min_plugin_info_interface_version[plugin->type] ||
+        ((*(int*)plugin->info) >> 8) >
+        (cur_plugin_info_interface_version[plugin->type] >> 8))
+    {
+      char buf[256];
+      strxnmov(buf, sizeof(buf) - 1, "API version for ",
+               plugin_type_names[plugin->type].str,
+               " plugin ", tmp.name.str,
+               " not supported by this version of the server", NullS);
+      report_error(report, ER_CANT_OPEN_LIBRARY, dl->str, ENOEXEC, buf);
+      goto err;
+    }
+    if (plugin_maturity_map[plugin->maturity] < plugin_maturity)
+    {
+      char buf[256];
+      strxnmov(buf, sizeof(buf) - 1, "Loading of ",
+               plugin_maturity_names[plugin->maturity],
+               " plugin ", tmp.name.str,
+               " is prohibited by --plugin-maturity=",
+               plugin_maturity_names[plugin_maturity],
+               NullS);
+      report_error(report, ER_CANT_OPEN_LIBRARY, dl->str, EPERM, buf);
+      goto err;
+    }
+    tmp.plugin= plugin;
+    tmp.ref_count= 0;
+    tmp.state= PLUGIN_IS_UNINITIALIZED;
+    tmp.load_option= PLUGIN_ON;
 
-      if (!(tmp_plugin_ptr= plugin_insert_or_reuse(&tmp)))
-        goto err;
-      if (my_hash_insert(&plugin_hash[plugin->type], (uchar*)tmp_plugin_ptr))
-        tmp_plugin_ptr->state= PLUGIN_IS_FREED;
-      init_alloc_root(&tmp_plugin_ptr->mem_root, 4096, 4096);
+    if (!(tmp_plugin_ptr= plugin_insert_or_reuse(&tmp)))
+      goto err;
+    if (my_hash_insert(&plugin_hash[plugin->type], (uchar*)tmp_plugin_ptr))
+      tmp_plugin_ptr->state= PLUGIN_IS_FREED;
+    init_alloc_root(&tmp_plugin_ptr->mem_root, 4096, 4096);
 
     if (name->str)
       DBUG_RETURN(FALSE); // all done
@@ -1822,10 +1822,10 @@ static bool plugin_load_list(MEM_ROOT *tmp_root, const char *list)
     case '\0':
       list= NULL; /* terminate the loop */
       /* fall through */
+    case ';':
 #ifndef __WIN__
     case ':':     /* can't use this as delimiter as it may be drive letter */
 #endif
-    case ';':
       str->str[str->length]= '\0';
       if (str == &name)  // load all plugins in named module
       {
@@ -1863,6 +1863,7 @@ static bool plugin_load_list(MEM_ROOT *tmp_root, const char *list)
         str->str= p;
         continue;
       }
+      /* fall through */
     default:
       str->length++;
       continue;
@@ -3947,4 +3948,3 @@ void add_plugin_options(DYNAMIC_ARRAY *options, MEM_ROOT *mem_root)
         insert_dynamic(options, (uchar*) opt);
   }
 }
-
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index 851e4f7b8ab..faaeaf51573 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -2075,6 +2075,7 @@ static bool check_prepared_statement(Prepared_statement *stmt)
     if (res != 2)
       break;
 
+    /* fall through */
   case SQLCOM_UPDATE_MULTI:
     res= mysql_test_multiupdate(stmt, tables, res == 2);
     break;
diff --git a/sql/sql_repl.cc b/sql/sql_repl.cc
index 871cb27f0d0..ca6e8d15e7a 100644
--- a/sql/sql_repl.cc
+++ b/sql/sql_repl.cc
@@ -1139,6 +1139,7 @@ impossible position";
           loop_breaker = (flags & BINLOG_DUMP_NON_BLOCK);
           break;
         }
+        /* fall through */
       default:
 	errmsg = "could not find next log";
 	my_errno= ER_MASTER_FATAL_ERROR_READING_BINLOG;
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index 512548b1d51..8789f0c9f24 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -931,6 +931,7 @@ public:
         is_handled= FALSE;
         break;
       }
+      /* fall through */
     case ER_COLUMNACCESS_DENIED_ERROR:
     case ER_VIEW_NO_EXPLAIN: /* Error was anonymized, ignore all the same. */
     case ER_PROCACCESS_DENIED_ERROR:
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 6ab39d7f8c6..e6490876352 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -5504,7 +5504,7 @@ bool alter_table_manage_keys(TABLE *table, int indexes_were_disabled,
   case LEAVE_AS_IS:
     if (!indexes_were_disabled)
       break;
-    /* fall-through: disabled indexes */
+    /* fall-through */
   case DISABLE:
     error= table->file->ha_disable_indexes(HA_KEY_SWITCH_NONUNIQ_SAVE);
   }
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 35c7203ca0d..4805cd4c66a 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -4212,15 +4212,11 @@ size_number:
               switch (end_ptr[0])
               {
                 case 'g':
-                case 'G':
-                  text_shift_number+=10;
+                case 'G': text_shift_number+=30; break;
                 case 'm':
-                case 'M':
-                  text_shift_number+=10;
+                case 'M': text_shift_number+=20; break;
                 case 'k':
-                case 'K':
-                  text_shift_number+=10;
-                  break;
+                case 'K': text_shift_number+=10; break;
                 default:
                 {
                   my_error(ER_WRONG_SIZE_NUMBER, MYF(0));
diff --git a/storage/federated/ha_federated.cc b/storage/federated/ha_federated.cc
index adf4f0f4db2..8680c3aac25 100644
--- a/storage/federated/ha_federated.cc
+++ b/storage/federated/ha_federated.cc
@@ -1421,6 +1421,7 @@ bool ha_federated::create_where_from_key(String *to,
           }
           break;
         }
+        /* fall through */
       case HA_READ_KEY_OR_NEXT:
         DBUG_PRINT("info", ("federated HA_READ_KEY_OR_NEXT %d", i));
         if (emit_key_part_name(&tmp, key_part) ||
@@ -1440,6 +1441,7 @@ bool ha_federated::create_where_from_key(String *to,
             goto err;
           break;
         }
+        /* fall through */
       case HA_READ_KEY_OR_PREV:
         DBUG_PRINT("info", ("federated HA_READ_KEY_OR_PREV %d", i));
         if (emit_key_part_name(&tmp, key_part) ||
@@ -2973,6 +2975,7 @@ int ha_federated::extra(ha_extra_function operation)
     break;
   case HA_EXTRA_PREPARE_FOR_DROP:
     table_will_be_deleted = TRUE;
+    break;
   default:
     /* do nothing */
     DBUG_PRINT("info",("unhandled operation: %d", (uint) operation));
diff --git a/storage/federatedx/federatedx_io_mysql.cc b/storage/federatedx/federatedx_io_mysql.cc
index a2eaa345a18..ef3b1388200 100644
--- a/storage/federatedx/federatedx_io_mysql.cc
+++ b/storage/federatedx/federatedx_io_mysql.cc
@@ -263,9 +263,8 @@ ulong federatedx_io_mysql::savepoint_release(ulong sp)
     savept= dynamic_element(&savepoints, savepoints.elements - 1, SAVEPT *);
     if (savept->level < sp)
       break;
-  if ((savept->flags & (SAVEPOINT_REALIZED | 
-                        SAVEPOINT_RESTRICT)) == SAVEPOINT_REALIZED)
-    last= savept;
+    if ((savept->flags & (SAVEPOINT_REALIZED | SAVEPOINT_RESTRICT)) == SAVEPOINT_REALIZED)
+      last= savept;
     savepoints.elements--;
   }
 
@@ -291,8 +290,8 @@ ulong federatedx_io_mysql::savepoint_rollback(ulong sp)
   while (savepoints.elements)
   {
     savept= dynamic_element(&savepoints, savepoints.elements - 1, SAVEPT *);
-  if (savept->level <= sp)
-    break;
+    if (savept->level <= sp)
+      break;
     savepoints.elements--;
   }
 
diff --git a/storage/federatedx/ha_federatedx.cc b/storage/federatedx/ha_federatedx.cc
index c9b07a8f3c3..bafae614fab 100644
--- a/storage/federatedx/ha_federatedx.cc
+++ b/storage/federatedx/ha_federatedx.cc
@@ -1340,6 +1340,7 @@ bool ha_federatedx::create_where_from_key(String *to,
           }
           break;
         }
+        /* fall through */
       case HA_READ_KEY_OR_NEXT:
         DBUG_PRINT("info", ("federatedx HA_READ_KEY_OR_NEXT %d", i));
         if (emit_key_part_name(&tmp, key_part) ||
@@ -1359,6 +1360,7 @@ bool ha_federatedx::create_where_from_key(String *to,
             goto err;
           break;
         }
+        /* fall through */
       case HA_READ_KEY_OR_PREV:
         DBUG_PRINT("info", ("federatedx HA_READ_KEY_OR_PREV %d", i));
         if (emit_key_part_name(&tmp, key_part) ||
diff --git a/storage/heap/hp_create.c b/storage/heap/hp_create.c
index 2b705b0e3d7..0b5dc841ada 100644
--- a/storage/heap/hp_create.c
+++ b/storage/heap/hp_create.c
@@ -94,7 +94,7 @@ int heap_create(const char *name, HP_CREATE_INFO *create_info,
         case HA_KEYTYPE_VARBINARY1:
           /* Case-insensitiveness is handled in coll->hash_sort */
           keyinfo->seg[j].type= HA_KEYTYPE_VARTEXT1;
-          /* fall_through */
+          /* fall through */
         case HA_KEYTYPE_VARTEXT1:
           keyinfo->flag|= HA_VAR_LENGTH_KEY;
           length+= 2;
diff --git a/storage/heap/hp_extra.c b/storage/heap/hp_extra.c
index c83efd5af61..9a19f818d3b 100644
--- a/storage/heap/hp_extra.c
+++ b/storage/heap/hp_extra.c
@@ -34,6 +34,7 @@ int heap_extra(register HP_INFO *info, enum ha_extra_function function)
   switch (function) {
   case HA_EXTRA_RESET_STATE:
     heap_reset(info);
+    /* fall through */
   case HA_EXTRA_NO_READCHECK:
     info->opt_flag&= ~READ_CHECK_USED;	/* No readcheck */
     break;
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index 780f3a6f82f..3aabfc319c6 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -5129,7 +5129,7 @@ ha_innobase::innobase_lock_autoinc(void)
 				break;
 			}
 		}
-		/* Fall through to old style locking. */
+		/* fall through */
 
 	case AUTOINC_OLD_STYLE_LOCKING:
 		error = row_lock_table_autoinc_for_mysql(prebuilt);
@@ -7080,7 +7080,7 @@ create_options_are_valid(
 	case ROW_TYPE_DYNAMIC:
 		CHECK_ERROR_ROW_TYPE_NEEDS_FILE_PER_TABLE;
 		CHECK_ERROR_ROW_TYPE_NEEDS_GT_ANTELOPE;
-		/* fall through since dynamic also shuns KBS */
+		/* fall through */ /* since dynamic also shuns KBS */
 	case ROW_TYPE_COMPACT:
 	case ROW_TYPE_REDUNDANT:
 		if (kbs_specified) {
@@ -7326,6 +7326,7 @@ ha_innobase::create(
 			thd, MYSQL_ERROR::WARN_LEVEL_WARN,
 			ER_ILLEGAL_HA_CREATE_OPTION,
 			"InnoDB: assuming ROW_FORMAT=COMPACT.");
+		/* fall through */
 	case ROW_TYPE_DEFAULT:
 	case ROW_TYPE_COMPACT:
 		flags = DICT_TF_COMPACT;
diff --git a/storage/innobase/include/data0type.ic b/storage/innobase/include/data0type.ic
index 410970ac50e..515b6b249ef 100644
--- a/storage/innobase/include/data0type.ic
+++ b/storage/innobase/include/data0type.ic
@@ -477,7 +477,7 @@ dtype_get_fixed_size_low(
 #else /* !UNIV_HOTBACKUP */
 		return(len);
 #endif /* !UNIV_HOTBACKUP */
-		/* fall through for variable-length charsets */
+		/* fall through */ /* for variable-length charsets */
 	case DATA_VARCHAR:
 	case DATA_BINARY:
 	case DATA_DECIMAL:
diff --git a/storage/innobase/include/page0zip.ic b/storage/innobase/include/page0zip.ic
index e26fa3e3d94..a2fa13c94df 100644
--- a/storage/innobase/include/page0zip.ic
+++ b/storage/innobase/include/page0zip.ic
@@ -170,7 +170,7 @@ page_zip_rec_needs_ext(
 				ignored if zip_size == 0 */
 	ulint	zip_size)	/*!< in: compressed page size in bytes, or 0 */
 {
-	ut_ad(rec_size > comp ? REC_N_NEW_EXTRA_BYTES : REC_N_OLD_EXTRA_BYTES);
+	ut_ad(rec_size > (comp ? REC_N_NEW_EXTRA_BYTES : REC_N_OLD_EXTRA_BYTES));
 	ut_ad(ut_is_2pow(zip_size));
 	ut_ad(comp || !zip_size);
 
diff --git a/storage/innobase/row/row0mysql.c b/storage/innobase/row/row0mysql.c
index 6206bef6b56..8804e2c4e03 100644
--- a/storage/innobase/row/row0mysql.c
+++ b/storage/innobase/row/row0mysql.c
@@ -3495,7 +3495,7 @@ check_next_foreign:
 
 		row_mysql_handle_errors(&err, trx, NULL, NULL);
 
-		/* Fall through to raise error */
+		/* fall through */
 
 	default:
 		/* No other possible error returns */
@@ -4315,7 +4315,8 @@ loop:
 		fputs("  InnoDB: Warning: CHECK TABLE on ", stderr);
 		dict_index_name_print(stderr, prebuilt->trx, index);
 		fprintf(stderr, " returned %lu\n", ret);
-		/* fall through (this error is ignored by CHECK TABLE) */
+		/* this error is ignored by CHECK TABLE */
+		/* fall through */
 	case DB_END_OF_INDEX:
 func_exit:
 		mem_free(buf);
diff --git a/storage/innobase/row/row0purge.c b/storage/innobase/row/row0purge.c
index 5f3e4175544..7b25612ba4b 100644
--- a/storage/innobase/row/row0purge.c
+++ b/storage/innobase/row/row0purge.c
@@ -407,8 +407,8 @@ row_purge_remove_sec_if_poss_leaf(
 				goto func_exit;
 			}
 		}
-		/* fall through (the index entry is still needed,
-		or the deletion succeeded) */
+		/* the index entry is still needed, or the deletion succeeded */
+		/* fall through */
 	case ROW_NOT_DELETED_REF:
 		/* The index entry is still needed. */
 	case ROW_BUFFERED:
diff --git a/storage/innobase/row/row0sel.c b/storage/innobase/row/row0sel.c
index e027a382cee..f5f8153e116 100644
--- a/storage/innobase/row/row0sel.c
+++ b/storage/innobase/row/row0sel.c
@@ -2675,6 +2675,7 @@ row_sel_field_store_in_mysql_format(
 	case DATA_SYS:
 		/* These column types should never be shipped to MySQL. */
 		ut_ad(0);
+		/* fall through */
 
 	case DATA_CHAR:
 	case DATA_FIXBINARY:
diff --git a/storage/maria/ma_extra.c b/storage/maria/ma_extra.c
index 0847f3c729c..3ee70059e6f 100644
--- a/storage/maria/ma_extra.c
+++ b/storage/maria/ma_extra.c
@@ -157,6 +157,7 @@ int maria_extra(MARIA_HA *info, enum ha_extra_function function,
     if (info->s->data_file_type != DYNAMIC_RECORD)
       break;
     /* Remove read/write cache if dynamic rows */
+    /* fall through */
   case HA_EXTRA_NO_CACHE:
     if (info->opt_flag & (READ_CACHE_USED | WRITE_CACHE_USED))
     {
@@ -313,7 +314,7 @@ int maria_extra(MARIA_HA *info, enum ha_extra_function function,
     share->state.open_count= 1;
     share->changed= 1;
     _ma_mark_file_changed_now(share);
-    /* Fall trough */
+    /* fall through */
   case HA_EXTRA_PREPARE_FOR_RENAME:
   {
     my_bool do_flush= test(function != HA_EXTRA_PREPARE_FOR_DROP);
diff --git a/storage/maria/ma_key_recover.c b/storage/maria/ma_key_recover.c
index 502ac2b8809..48f01b8f8dd 100644
--- a/storage/maria/ma_key_recover.c
+++ b/storage/maria/ma_key_recover.c
@@ -1169,6 +1169,7 @@ uint _ma_apply_redo_index(MARIA_HA *info,
         goto err;
       }
       page_length= page.size;
+      break;
     }
     case KEY_OP_NONE:
     default:
diff --git a/storage/maria/ma_recovery.c b/storage/maria/ma_recovery.c
index b2e8705b15e..75a8f4f4559 100644
--- a/storage/maria/ma_recovery.c
+++ b/storage/maria/ma_recovery.c
@@ -3059,7 +3059,7 @@ static MARIA_HA *get_MARIA_HA_from_REDO_record(const
   case LOGREC_REDO_INDEX:
   case LOGREC_REDO_INDEX_FREE_PAGE:
     index_page_redo_entry= 1;
-    /* Fall trough*/
+    /* fall through*/
   case LOGREC_REDO_INSERT_ROW_HEAD:
   case LOGREC_REDO_INSERT_ROW_TAIL:
   case LOGREC_REDO_PURGE_ROW_HEAD:
diff --git a/storage/myisam/mi_extra.c b/storage/myisam/mi_extra.c
index dab1f66ed6d..9c5c1ad0c0d 100644
--- a/storage/myisam/mi_extra.c
+++ b/storage/myisam/mi_extra.c
@@ -150,6 +150,7 @@ int mi_extra(MI_INFO *info, enum ha_extra_function function, void *extra_arg)
     if (info->s->data_file_type != DYNAMIC_RECORD)
       break;
     /* Remove read/write cache if dynamic rows */
+    /* fall through */
   case HA_EXTRA_NO_CACHE:
     if (info->opt_flag & (READ_CACHE_USED | WRITE_CACHE_USED))
     {
@@ -262,7 +263,7 @@ int mi_extra(MI_INFO *info, enum ha_extra_function function, void *extra_arg)
     //share->deleting= TRUE;
     share->global_changed= FALSE;     /* force writing changed flag */
     _mi_mark_file_changed(info);
-    /* Fall trough */
+    /* fall through */
   case HA_EXTRA_PREPARE_FOR_RENAME:
     mysql_mutex_lock(&THR_LOCK_myisam);
     share->last_version= 0L;			/* Impossible version */
diff --git a/storage/sphinx/ha_sphinx.cc b/storage/sphinx/ha_sphinx.cc
index 9edf6ea6570..b7a333c1715 100644
--- a/storage/sphinx/ha_sphinx.cc
+++ b/storage/sphinx/ha_sphinx.cc
@@ -1661,13 +1661,16 @@ bool CSphSEQuery::ParseField ( char * sField )
 			char * sLat = sValue;
 			char * p = sValue;
 
-			if (!( p = strchr ( p, ',' ) )) break; *p++ = '\0';
+			if (!( p = strchr ( p, ',' ) )) break;
+                        *p++ = '\0';
 			char * sLong = p;
 
-			if (!( p = strchr ( p, ',' ) )) break; *p++ = '\0';
+			if (!( p = strchr ( p, ',' ) )) break;
+                        *p++ = '\0';
 			char * sLatVal = p;
 
-			if (!( p = strchr ( p, ',' ) )) break; *p++ = '\0';
+			if (!( p = strchr ( p, ',' ) )) break;
+                        *p++ = '\0';
 			char * sLongVal = p;
 
 			m_sGeoLatAttr = chop(sLat);
@@ -1736,7 +1739,8 @@ bool CSphSEQuery::ParseField ( char * sField )
 		while ( sRest )
 		{
 			char * sId = sRest;
-			if (!( sRest = strchr ( sRest, ':' ) )) break; *sRest++ = '\0';
+			if (!( sRest = strchr ( sRest, ':' ) )) break;
+                        *sRest++ = '\0';
 			if (!( sRest - sId )) break;
 
 			char * sValue = sRest;
diff --git a/storage/tokudb/CMakeLists.txt b/storage/tokudb/CMakeLists.txt
index 2052d448a43..ab6bb0a8504 100644
--- a/storage/tokudb/CMakeLists.txt
+++ b/storage/tokudb/CMakeLists.txt
@@ -100,6 +100,7 @@ endmacro(append_cflags_if_supported)
 
 set_cflags_if_supported(-Wno-missing-field-initializers)
 append_cflags_if_supported(-Wno-vla)
+append_cflags_if_supported(-Wno-implicit-fallthrough)
 
 ADD_SUBDIRECTORY(ft-index)
 
diff --git a/storage/xtradb/handler/ha_innodb.cc b/storage/xtradb/handler/ha_innodb.cc
index 66fcc2799bb..00f345d4bc1 100644
--- a/storage/xtradb/handler/ha_innodb.cc
+++ b/storage/xtradb/handler/ha_innodb.cc
@@ -6144,7 +6144,7 @@ ha_innobase::innobase_lock_autoinc(void)
 				break;
 			}
 		}
-		/* Fall through to old style locking. */
+		/* fall through */
 
 	case AUTOINC_OLD_STYLE_LOCKING:
 		error = row_lock_table_autoinc_for_mysql(prebuilt);
@@ -8190,7 +8190,7 @@ create_options_are_valid(
 	case ROW_TYPE_DYNAMIC:
 		CHECK_ERROR_ROW_TYPE_NEEDS_FILE_PER_TABLE;
 		CHECK_ERROR_ROW_TYPE_NEEDS_GT_ANTELOPE;
-		/* fall through since dynamic also shuns KBS */
+		/* fall through */ /* since dynamic also shuns KBS */
 	case ROW_TYPE_COMPACT:
 	case ROW_TYPE_REDUNDANT:
 		if (kbs_specified) {
@@ -8436,6 +8436,7 @@ ha_innobase::create(
 			thd, MYSQL_ERROR::WARN_LEVEL_WARN,
 			ER_ILLEGAL_HA_CREATE_OPTION,
 			"InnoDB: assuming ROW_FORMAT=COMPACT.");
+		/* fall through */
 	case ROW_TYPE_DEFAULT:
 	case ROW_TYPE_COMPACT:
 		flags = DICT_TF_COMPACT;
diff --git a/storage/xtradb/include/data0type.ic b/storage/xtradb/include/data0type.ic
index 410970ac50e..5848e5d6548 100644
--- a/storage/xtradb/include/data0type.ic
+++ b/storage/xtradb/include/data0type.ic
@@ -477,7 +477,7 @@ dtype_get_fixed_size_low(
 #else /* !UNIV_HOTBACKUP */
 		return(len);
 #endif /* !UNIV_HOTBACKUP */
-		/* fall through for variable-length charsets */
+		/* fall through */
 	case DATA_VARCHAR:
 	case DATA_BINARY:
 	case DATA_DECIMAL:
diff --git a/storage/xtradb/include/page0zip.ic b/storage/xtradb/include/page0zip.ic
index e26fa3e3d94..a2fa13c94df 100644
--- a/storage/xtradb/include/page0zip.ic
+++ b/storage/xtradb/include/page0zip.ic
@@ -170,7 +170,7 @@ page_zip_rec_needs_ext(
 				ignored if zip_size == 0 */
 	ulint	zip_size)	/*!< in: compressed page size in bytes, or 0 */
 {
-	ut_ad(rec_size > comp ? REC_N_NEW_EXTRA_BYTES : REC_N_OLD_EXTRA_BYTES);
+	ut_ad(rec_size > (comp ? REC_N_NEW_EXTRA_BYTES : REC_N_OLD_EXTRA_BYTES));
 	ut_ad(ut_is_2pow(zip_size));
 	ut_ad(comp || !zip_size);
 
diff --git a/storage/xtradb/row/row0mysql.c b/storage/xtradb/row/row0mysql.c
index 0182752132a..5b01adf7c82 100644
--- a/storage/xtradb/row/row0mysql.c
+++ b/storage/xtradb/row/row0mysql.c
@@ -3635,7 +3635,7 @@ check_next_foreign:
 
 		row_mysql_handle_errors(&err, trx, NULL, NULL);
 
-		/* Fall through to raise error */
+		/* fall through */ /* to raise error */
 
 	default:
 		/* No other possible error returns */
@@ -4455,7 +4455,7 @@ loop:
 		fputs("  InnoDB: Warning: CHECK TABLE on ", stderr);
 		dict_index_name_print(stderr, prebuilt->trx, index);
 		fprintf(stderr, " returned %lu\n", ret);
-		/* fall through (this error is ignored by CHECK TABLE) */
+		/* fall through */ /* this error is ignored by CHECK TABLE */
 	case DB_END_OF_INDEX:
 func_exit:
 		mem_free(buf);
diff --git a/storage/xtradb/row/row0purge.c b/storage/xtradb/row/row0purge.c
index 4186da884b6..77d60edb71f 100644
--- a/storage/xtradb/row/row0purge.c
+++ b/storage/xtradb/row/row0purge.c
@@ -407,8 +407,8 @@ row_purge_remove_sec_if_poss_leaf(
 				goto func_exit;
 			}
 		}
-		/* fall through (the index entry is still needed,
-		or the deletion succeeded) */
+		/* the index entry is still needed, or the deletion succeeded */
+		/* fall through */
 	case ROW_NOT_DELETED_REF:
 		/* The index entry is still needed. */
 	case ROW_BUFFERED:
diff --git a/storage/xtradb/row/row0sel.c b/storage/xtradb/row/row0sel.c
index 592ae963382..3b2568c6834 100644
--- a/storage/xtradb/row/row0sel.c
+++ b/storage/xtradb/row/row0sel.c
@@ -2678,6 +2678,7 @@ row_sel_field_store_in_mysql_format(
 	case DATA_SYS:
 		/* These column types should never be shipped to MySQL. */
 		ut_ad(0);
+		/* fall through */
 
 	case DATA_CHAR:
 	case DATA_FIXBINARY:
diff --git a/strings/ctype-utf8.c b/strings/ctype-utf8.c
index f2782657bea..7d39c9127c3 100644
--- a/strings/ctype-utf8.c
+++ b/strings/ctype-utf8.c
@@ -2488,14 +2488,18 @@ static int my_uni_utf8 (CHARSET_INFO *cs __attribute__((unused)),
     return MY_CS_TOOSMALLN(count);
 
   switch (count) {
-    /* Fall through all cases!!! */
 #ifdef UNICODE_32BIT
     case 6: r[5] = (uchar) (0x80 | (wc & 0x3f)); wc = wc >> 6; wc |= 0x4000000;
+      /* fall through */
     case 5: r[4] = (uchar) (0x80 | (wc & 0x3f)); wc = wc >> 6; wc |= 0x200000;
+      /* fall through */
     case 4: r[3] = (uchar) (0x80 | (wc & 0x3f)); wc = wc >> 6; wc |= 0x10000;
+      /* fall through */
 #endif
     case 3: r[2] = (uchar) (0x80 | (wc & 0x3f)); wc = wc >> 6; wc |= 0x800;
+      /* fall through */
     case 2: r[1] = (uchar) (0x80 | (wc & 0x3f)); wc = wc >> 6; wc |= 0xc0;
+      /* fall through */
     case 1: r[0] = (uchar) wc;
   }
   return count;
@@ -2521,9 +2525,10 @@ static int my_uni_utf8_no_range(CHARSET_INFO *cs __attribute__((unused)),
 
   switch (count)
   {
-    /* Fall through all cases!!! */
     case 3: r[2]= (uchar) (0x80 | (wc & 0x3f)); wc= wc >> 6; wc |= 0x800;
+      /* fall through */
     case 2: r[1]= (uchar) (0x80 | (wc & 0x3f)); wc= wc >> 6; wc |= 0xc0;
+      /* fall through */
     case 1: r[0]= (uchar) wc;
   }
   return count;
@@ -4979,10 +4984,12 @@ my_wc_mb_utf8mb4(CHARSET_INFO *cs __attribute__((unused)),
     return MY_CS_TOOSMALLN(count);
 
   switch (count) {
-    /* Fall through all cases!!! */
     case 4: r[3] = (uchar) (0x80 | (wc & 0x3f)); wc = wc >> 6; wc |= 0x10000;
+      /* fall through */
     case 3: r[2] = (uchar) (0x80 | (wc & 0x3f)); wc = wc >> 6; wc |= 0x800;
+      /* fall through */
     case 2: r[1] = (uchar) (0x80 | (wc & 0x3f)); wc = wc >> 6; wc |= 0xc0;
+      /* fall through */
     case 1: r[0] = (uchar) wc;
   }
   return count;
@@ -5011,10 +5018,12 @@ my_wc_mb_utf8mb4_no_range(CHARSET_INFO *cs __attribute__((unused)),
 
   switch (count)
   {
-    /* Fall through all cases!!! */
     case 4: r[3]= (uchar) (0x80 | (wc & 0x3f)); wc= wc >> 6; wc |= 0x10000;
+      /* fall through */
     case 3: r[2]= (uchar) (0x80 | (wc & 0x3f)); wc= wc >> 6; wc |= 0x800;
+      /* fall through */
     case 2: r[1]= (uchar) (0x80 | (wc & 0x3f)); wc= wc >> 6; wc |= 0xc0;
+      /* fall through */
     case 1: r[0]= (uchar) wc;
   }
   return count;
diff --git a/strings/dtoa.c b/strings/dtoa.c
index 6b216056f66..5f50e10c9bf 100644
--- a/strings/dtoa.c
+++ b/strings/dtoa.c
@@ -1377,7 +1377,7 @@ static double my_strtod_int(const char *s00, char **se, int *error, char *buf, s
     switch (*s) {
     case '-':
       sign= 1;
-      /* no break */
+      /* fall through */
     case '+':
       s++;
       goto break2;
@@ -1465,10 +1465,9 @@ static double my_strtod_int(const char *s00, char **se, int *error, char *buf, s
     esign= 0;
     if (++s < end)
       switch (c= *s) {
-      case '-':
-        esign= 1;
-      case '+':
-        c= *++s;
+      case '-': esign= 1;
+        /* fall through */
+      case '+': c= *++s;
       }
     if (s < end && c >= '0' && c <= '9')
     {
@@ -2360,7 +2359,7 @@ static char *dtoa(double dd, int mode, int ndigits, int *decpt, int *sign,
     break;
   case 2:
     leftright= 0;
-    /* no break */
+    /* fall through */
   case 4:
     if (ndigits <= 0)
       ndigits= 1;
@@ -2368,7 +2367,7 @@ static char *dtoa(double dd, int mode, int ndigits, int *decpt, int *sign,
     break;
   case 3:
     leftright= 0;
-    /* no break */
+    /* fall through */
   case 5:
     i= ndigits + k + 1;
     ilim= i;