Silence bogus GCC 7 warnings -Wimplicit-fallthrough

Do not silence uncertain cases, or fix any bugs.

The only functional change should be that ha_federated::extra()
is not calling DBUG_PRINT to report an unhandled case for
HA_EXTRA_PREPARE_FOR_DROP.

39 files changed, 106 insertions, 49 deletions

diff --git a/storage/connect/array.cpp b/storage/connect/array.cpp
index 1998ab890e9..88ab85d20eb 100644
--- a/storage/connect/array.cpp
+++ b/storage/connect/array.cpp
@@ -155,6 +155,7 @@ ARRAY::ARRAY(PGLOBAL g, int type, int size, int length, int prec)
   switch (type) {
     case TYPE_STRING:
       Len = length;
+      /* fall through */
     case TYPE_SHORT:
     case TYPE_INT:
     case TYPE_DOUBLE:
@@ -592,6 +593,7 @@ int ARRAY::Convert(PGLOBAL g, int k, PVAL vp)
   switch (Type) {
     case TYPE_DOUBLE:
       prec = 2;
+      /* fall through */
     case TYPE_SHORT:
     case TYPE_INT:
     case TYPE_DATE:
diff --git a/storage/connect/filamdbf.cpp b/storage/connect/filamdbf.cpp
index 9feb61d7d61..fec98a72544 100644
--- a/storage/connect/filamdbf.cpp
+++ b/storage/connect/filamdbf.cpp
@@ -503,7 +503,8 @@ bool DBFFAM::OpenTableFile(PGLOBAL g)
         break;
         } // endif
 
-      // Selective delete, pass thru
+      // Selective delete
+      /* fall through */
     case MODE_UPDATE:
       UseTemp = Tdbp->IsUsingTemp(g);
       strcpy(opmode, (UseTemp) ? "rb" : "r+b");
@@ -623,6 +624,7 @@ bool DBFFAM::AllocateBuffer(PGLOBAL g)
             case 'L':           // Large (big) integer
             case 'T':           // Tiny integer
               c = 'N';          // Numeric
+              /* fall through */
             case 'N':           // Numeric (integer)
             case 'F':           // Float (double)
               descp->Decimals = (uchar)cdp->F.Prec;
diff --git a/storage/connect/filamfix.cpp b/storage/connect/filamfix.cpp
index cd25429318a..dcb677dc848 100644
--- a/storage/connect/filamfix.cpp
+++ b/storage/connect/filamfix.cpp
@@ -919,7 +919,8 @@ bool BGXFAM::OpenTableFile(PGLOBAL g)
         break;
         } // endif
 
-      // Selective delete, pass thru
+      // Selective delete
+      /* fall through */
     case MODE_UPDATE:
       UseTemp = Tdbp->IsUsingTemp(g);
       oflag |= (UseTemp) ? O_RDONLY : O_RDWR;
diff --git a/storage/connect/filamtxt.cpp b/storage/connect/filamtxt.cpp
index e53cdcd9ba9..12c0a66ecad 100644
--- a/storage/connect/filamtxt.cpp
+++ b/storage/connect/filamtxt.cpp
@@ -561,6 +561,7 @@ bool DOSFAM::OpenTableFile(PGLOBAL g)
 
       // Selective delete, pass thru
       Bin = true;
+      /* fall through */
     case MODE_UPDATE:
       if ((UseTemp = Tdbp->IsUsingTemp(g))) {
         strcpy(opmode, "r");
diff --git a/storage/connect/filamvct.cpp b/storage/connect/filamvct.cpp
index fdc5433f4a4..71a8dd98c61 100755
--- a/storage/connect/filamvct.cpp
+++ b/storage/connect/filamvct.cpp
@@ -440,6 +440,7 @@ bool VCTFAM::OpenTableFile(PGLOBAL g)
         } // endif
 
       // Selective delete, pass thru
+      /* fall through */
     case MODE_UPDATE:
       UseTemp = Tdbp->IsUsingTemp(g);
       strcpy(opmode, (UseTemp) ? "rb" : "r+b");
@@ -1918,6 +1919,7 @@ bool VECFAM::OpenTableFile(PGLOBAL g)
         } // endif filter
 
       // Selective delete, pass thru
+      /* fall through */
     case MODE_UPDATE:
       UseTemp = Tdbp->IsUsingTemp(g);
       strcpy(opmode, (UseTemp) ? "rb": "r+b");
@@ -3584,6 +3586,7 @@ bool BGVFAM::OpenTableFile(PGLOBAL g)
         } // endif
 
       // Selective delete, pass thru
+      /* fall through */
     case MODE_UPDATE:
       UseTemp = Tdbp->IsUsingTemp(g);
       oflag = (UseTemp) ? O_RDONLY : O_RDWR;
diff --git a/storage/connect/filter.cpp b/storage/connect/filter.cpp
index 262d6b58a70..35840e9b5e3 100644
--- a/storage/connect/filter.cpp
+++ b/storage/connect/filter.cpp
@@ -1193,7 +1193,7 @@ bool FILTER::Convert(PGLOBAL g, bool having)
           Arg(0) = pXVOID;
           } // endif void
 
-        // pass thru
+        // fall through
       case OP_IN:
         // For IN operator do optimize if operand is an array
         if (GetArgType(1) != TYPE_ARRAY)
@@ -1260,6 +1260,7 @@ bool FILTER::Eval(PGLOBAL g)
         } // endif Opm
 
       // For modified operators, pass thru
+      /* fall through */
     case OP_IN:
     case OP_EXIST:
       // For IN operations, special processing is done here
diff --git a/storage/connect/ha_connect.cc b/storage/connect/ha_connect.cc
index 1f2bd0e5992..e646069c219 100644
--- a/storage/connect/ha_connect.cc
+++ b/storage/connect/ha_connect.cc
@@ -1427,7 +1427,7 @@ void *ha_connect::GetColumnOption(PGLOBAL g, void *field, PCOLINFO pcf)
     case MYSQL_TYPE_VARCHAR:
     case MYSQL_TYPE_VAR_STRING:
       pcf->Flags |= U_VAR;
-      /* no break */
+      /* fall through */
     default:
       pcf->Type= MYSQLtoPLG(fp->type(), &v);
       break;
@@ -2801,6 +2801,7 @@ PCFIL ha_connect::CheckCond(PGLOBAL g, PCFIL filp, const Item *cond)
 			case Item_func::LIKE_FUNC:   vop= OP_LIKE; break;
 			case Item_func::ISNOTNULL_FUNC:
 				neg = true;
+				/* fall through */
 			case Item_func::ISNULL_FUNC: vop= OP_NULL; break;
 			case Item_func::IN_FUNC:     vop= OP_IN;
       case Item_func::BETWEEN:
@@ -4220,7 +4221,8 @@ bool ha_connect::check_privileges(THD *thd, PTOS options, char *dbn, bool quick)
       } else
         return false;
 
-      /* Fall through to check FILE_ACL */
+      /* check FILE_ACL */
+      /* fall through */
     case TAB_ODBC:
 		case TAB_JDBC:
 		case TAB_MYSQL:
@@ -5454,7 +5456,7 @@ static int connect_assisted_discovery(handlerton *, THD* thd,
 #endif   // JDBC_SUPPORT
 		case TAB_DBF:
       dbf= true;
-      // Passthru
+      // fall through
     case TAB_CSV:
       if (!fn && fnc != FNC_NO)
         sprintf(g->Message, "Missing %s file name", topt->type);
diff --git a/storage/connect/json.cpp b/storage/connect/json.cpp
index b473871e9f7..6904295066f 100644
--- a/storage/connect/json.cpp
+++ b/storage/connect/json.cpp
@@ -533,7 +533,7 @@ PVAL ParseNumeric(PGLOBAL g, int& i, STRG& src)
         if (!has_e)
           goto err;
 
-        // passthru
+        // fall through
       case '-':
         if (found_digit)
           goto err;
@@ -826,7 +826,7 @@ bool JOUTSTR::Escape(const char *s)
       case '\r':
       case '\b':
       case '\f': WriteChr('\\');
-        // passthru
+        // fall through
       default:
         WriteChr(s[i]);
         break;
diff --git a/storage/connect/plgdbutl.cpp b/storage/connect/plgdbutl.cpp
index 1910cdcdec8..52c6058393f 100644
--- a/storage/connect/plgdbutl.cpp
+++ b/storage/connect/plgdbutl.cpp
@@ -917,7 +917,7 @@ int PlugCloseFile(PGLOBAL g __attribute__((unused)), PFBLOCK fp, bool all)
 
       fp->Memory = NULL;
       fp->Mode = MODE_ANY;
-      // Passthru
+      // fall through
     case TYPE_FB_HANDLE:
       if (fp->Handle && fp->Handle != INVALID_HANDLE_VALUE)
         if (CloseFileHandle(fp->Handle))
diff --git a/storage/connect/reldef.cpp b/storage/connect/reldef.cpp
index 5bb7848ab1c..0bb7adcce83 100644
--- a/storage/connect/reldef.cpp
+++ b/storage/connect/reldef.cpp
@@ -128,6 +128,7 @@ int RELDEF::GetSizeCatInfo(PSZ what, PSZ sdef)
     switch (toupper(c)) {
       case 'M':
         n *= 1024;
+        // fall through
       case 'K':
         n *= 1024;
       } // endswitch c
diff --git a/storage/connect/tabdos.cpp b/storage/connect/tabdos.cpp
index d2bb3d7a4af..2da92741e4f 100644
--- a/storage/connect/tabdos.cpp
+++ b/storage/connect/tabdos.cpp
@@ -1307,6 +1307,7 @@ PBF TDBDOS::InitBlockFilter(PGLOBAL g, PFIL filp)
         } // endif !opm
 
       // if opm, pass thru
+      /* fall through */
     case OP_IN:
       if (filp->GetArgType(0) == TYPE_COLBLK &&
           filp->GetArgType(1) == TYPE_ARRAY) {
diff --git a/storage/connect/tabjson.cpp b/storage/connect/tabjson.cpp
index 1e11d454cfc..2addcc139fb 100644
--- a/storage/connect/tabjson.cpp
+++ b/storage/connect/tabjson.cpp
@@ -1530,7 +1530,7 @@ void JSONCOL::WriteColumn(PGLOBAL g)
         break;
         } // endif Op
 
-      // Passthru
+      // fall through
     case TYPE_DATE:
     case TYPE_INT:
 		case TYPE_SHORT:
diff --git a/storage/connect/value.cpp b/storage/connect/value.cpp
index ced690e77c0..7660ee0a630 100644
--- a/storage/connect/value.cpp
+++ b/storage/connect/value.cpp
@@ -118,7 +118,7 @@ ulonglong CharToNumber(char *p, int n, ulonglong maxval,
         maxval++;
         if (minus) *minus = true;
       } // endif Unsigned
-
+      /* fall through */
     case '+':
       p++;
       break;
diff --git a/storage/connect/xindex.cpp b/storage/connect/xindex.cpp
index 15fb71ab88a..ae210cb900c 100755
--- a/storage/connect/xindex.cpp
+++ b/storage/connect/xindex.cpp
@@ -464,7 +464,7 @@ bool XINDEX::Make(PGLOBAL g, PIXDEF sxp)
         if (ApplyFilter(g, filp))
           break;
 
-        // passthru
+        // fall through
       case RC_NF:
         continue;
       case RC_EF:
diff --git a/storage/connect/xobject.cpp b/storage/connect/xobject.cpp
index a0b7849543d..746de097918 100644
--- a/storage/connect/xobject.cpp
+++ b/storage/connect/xobject.cpp
@@ -405,7 +405,7 @@ bool STRING::Append_quoted(PSZ s)
       case '\r':
       case '\b':
       case '\f': b |= Append('\\');
-        // passthru
+        // fall through
       default:
         b |= Append(*p);
         break;
diff --git a/storage/federated/ha_federated.cc b/storage/federated/ha_federated.cc
index 97baa27aba6..927921d6df4 100644
--- a/storage/federated/ha_federated.cc
+++ b/storage/federated/ha_federated.cc
@@ -1,4 +1,5 @@
 /* Copyright (c) 2004, 2015, Oracle and/or its affiliates.
+   Copyright (c) 2017, MariaDB Corporation.
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -2952,6 +2953,7 @@ 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/heap/hp_create.c b/storage/heap/hp_create.c
index a68a35e63fb..d03c7c46f15 100644
--- a/storage/heap/hp_create.c
+++ b/storage/heap/hp_create.c
@@ -1,5 +1,5 @@
 /* Copyright (c) 2000, 2011, Oracle and/or its affiliates.
-   Copyright (c) 2010, 2014, SkySQL Ab.
+   Copyright (c) 2010, 2017, MariaDB Corporation.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -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/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index 1538471db4f..dac70203ee4 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -7063,8 +7063,8 @@ ha_innobase::innobase_lock_autoinc(void)
 				break;
 			}
 		}
-		/* Fall through to old style locking. */
-
+		/* Use old style locking. */
+		/* fall through */
 	case AUTOINC_OLD_STYLE_LOCKING:
 		DBUG_EXECUTE_IF("die_if_autoinc_old_lock_style_used",
 				ut_ad(0););
@@ -9725,7 +9725,8 @@ create_options_are_invalid(
 	case ROW_TYPE_DYNAMIC:
 		CHECK_ERROR_ROW_TYPE_NEEDS_FILE_PER_TABLE(use_tablespace);
 		CHECK_ERROR_ROW_TYPE_NEEDS_GT_ANTELOPE;
-		/* fall through since dynamic also shuns KBS */
+		/* ROW_FORMAT=DYNAMIC also shuns KEY_BLOCK_SIZE */
+		/* fall through */
 	case ROW_TYPE_COMPACT:
 	case ROW_TYPE_REDUNDANT:
 		if (kbs_specified) {
@@ -10111,7 +10112,8 @@ index_bad:
 			break;
 		}
 		zip_allowed = FALSE;
-		/* fall through to set row_format = COMPACT */
+		/* Set ROW_FORMAT = COMPACT */
+		/* fall through */
 	case ROW_TYPE_NOT_USED:
 	case ROW_TYPE_FIXED:
 	case ROW_TYPE_PAGE:
@@ -10119,6 +10121,7 @@ index_bad:
 			thd, Sql_condition::WARN_LEVEL_WARN,
 			ER_ILLEGAL_HA_CREATE_OPTION,
 			"InnoDB: assuming ROW_FORMAT=COMPACT.");
+		/* fall through */
 	case ROW_TYPE_DEFAULT:
 		/* If we fell through, set row format to Compact. */
 		row_format = ROW_TYPE_COMPACT;
diff --git a/storage/innobase/include/data0type.ic b/storage/innobase/include/data0type.ic
index d489bef89a8..b4dbf4b1213 100644
--- a/storage/innobase/include/data0type.ic
+++ b/storage/innobase/include/data0type.ic
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2012, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -574,7 +575,8 @@ dtype_get_fixed_size_low(
 #else /* !UNIV_HOTBACKUP */
 		return(len);
 #endif /* !UNIV_HOTBACKUP */
-		/* fall through for variable-length charsets */
+		/* Treat as variable-length. */
+		/* Fall through */
 	case DATA_VARCHAR:
 	case DATA_BINARY:
 	case DATA_DECIMAL:
diff --git a/storage/innobase/include/mach0data.ic b/storage/innobase/include/mach0data.ic
index 6b303979b18..9a8441280a6 100644
--- a/storage/innobase/include/mach0data.ic
+++ b/storage/innobase/include/mach0data.ic
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1995, 2009, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -787,13 +788,13 @@ mach_swap_byte_order(
         dest += len;
 
         switch (len & 0x7) {
-        case 0: *--dest = *from++;
-        case 7: *--dest = *from++;
-        case 6: *--dest = *from++;
-        case 5: *--dest = *from++;
-        case 4: *--dest = *from++;
-        case 3: *--dest = *from++;
-        case 2: *--dest = *from++;
+        case 0: *--dest = *from++; /* fall through */
+        case 7: *--dest = *from++; /* fall through */
+        case 6: *--dest = *from++; /* fall through */
+        case 5: *--dest = *from++; /* fall through */
+        case 4: *--dest = *from++; /* fall through */
+        case 3: *--dest = *from++; /* fall through */
+        case 2: *--dest = *from++; /* fall through */
         case 1: *--dest = *from;
         }
 }
diff --git a/storage/innobase/include/ut0rnd.ic b/storage/innobase/include/ut0rnd.ic
index 024c59e553b..987dfac03c1 100644
--- a/storage/innobase/include/ut0rnd.ic
+++ b/storage/innobase/include/ut0rnd.ic
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1994, 2009, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -237,16 +238,22 @@ ut_fold_binary(
 	switch (len & 0x7) {
 	case 7:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 6:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 5:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 4:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 3:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 2:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 1:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
 	}
diff --git a/storage/innobase/row/row0import.cc b/storage/innobase/row/row0import.cc
index da8e1aab2c9..1337496b897 100644
--- a/storage/innobase/row/row0import.cc
+++ b/storage/innobase/row/row0import.cc
@@ -2018,6 +2018,7 @@ PageConverter::update_page(
 	case FIL_PAGE_TYPE_XDES:
 		err = set_current_xdes(
 			buf_block_get_page_no(block), get_frame(block));
+		/* fall through */
 	case FIL_PAGE_INODE:
 	case FIL_PAGE_TYPE_TRX_SYS:
 	case FIL_PAGE_IBUF_FREE_LIST:
diff --git a/storage/innobase/row/row0log.cc b/storage/innobase/row/row0log.cc
index 77cca37ddd1..3a49f033c9c 100644
--- a/storage/innobase/row/row0log.cc
+++ b/storage/innobase/row/row0log.cc
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 2011, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -1872,6 +1873,7 @@ row_log_table_apply_update(
 
 		When applying the subsequent ROW_T_DELETE, no matching
 		record will be found. */
+		/* fall through */
 	case DB_SUCCESS:
 		ut_ad(row != NULL);
 		break;
diff --git a/storage/innobase/row/row0mysql.cc b/storage/innobase/row/row0mysql.cc
index a3f4355ec6c..69d77060bd8 100644
--- a/storage/innobase/row/row0mysql.cc
+++ b/storage/innobase/row/row0mysql.cc
@@ -5407,7 +5407,8 @@ 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.cc b/storage/innobase/row/row0purge.cc
index bc2e0b0e1cb..bb883310820 100644
--- a/storage/innobase/row/row0purge.cc
+++ b/storage/innobase/row/row0purge.cc
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1997, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -488,8 +489,9 @@ row_purge_remove_sec_if_poss_leaf(
 				success = false;
 			}
 		}
-		/* fall through (the index entry is still needed,
+		/* (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/sync/sync0sync.cc b/storage/innobase/sync/sync0sync.cc
index a2165a917b8..855fd5dec11 100644
--- a/storage/innobase/sync/sync0sync.cc
+++ b/storage/innobase/sync/sync0sync.cc
@@ -1123,6 +1123,7 @@ sync_thread_add_level(
 			upgrading in innobase_start_or_create_for_mysql(). */
 			break;
 		}
+		/* fall through */
 	case SYNC_MEM_POOL:
 	case SYNC_MEM_HASH:
 	case SYNC_RECV:
diff --git a/storage/maria/ma_extra.c b/storage/maria/ma_extra.c
index fd21d2863f8..c6f53eaa24b 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= MY_TEST(function != HA_EXTRA_PREPARE_FOR_DROP);
diff --git a/storage/maria/ma_recovery.c b/storage/maria/ma_recovery.c
index 59e0630be8c..a09662544a2 100644
--- a/storage/maria/ma_recovery.c
+++ b/storage/maria/ma_recovery.c
@@ -3061,7 +3061,7 @@ 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 a47c1987e38..04e32378fd3 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/spider/spd_db_conn.cc b/storage/spider/spd_db_conn.cc
index c29172a474a..495420dad32 100644
--- a/storage/spider/spd_db_conn.cc
+++ b/storage/spider/spd_db_conn.cc
@@ -1844,8 +1844,8 @@ int spider_db_append_key_where_internal(
 #if defined(MARIADB_BASE_VERSION) && MYSQL_VERSION_ID >= 100000
           case HA_READ_PREFIX_LAST:
             result_list->desc_flg = TRUE;
-            /* fall through */
 #endif
+            /* fall through */
           case HA_READ_KEY_EXACT:
             if (sql_kind == SPIDER_SQL_KIND_SQL)
             {
diff --git a/storage/xtradb/handler/ha_innodb.cc b/storage/xtradb/handler/ha_innodb.cc
index 6c390328258..2c6f844d026 100644
--- a/storage/xtradb/handler/ha_innodb.cc
+++ b/storage/xtradb/handler/ha_innodb.cc
@@ -7749,8 +7749,8 @@ ha_innobase::innobase_lock_autoinc(void)
 				break;
 			}
 		}
-		/* Fall through to old style locking. */
-
+		/* Use old style locking. */
+		/* fall through */
 	case AUTOINC_OLD_STYLE_LOCKING:
 		DBUG_EXECUTE_IF("die_if_autoinc_old_lock_style_used",
 				ut_ad(0););
@@ -10473,7 +10473,8 @@ create_options_are_invalid(
 	case ROW_TYPE_DYNAMIC:
 		CHECK_ERROR_ROW_TYPE_NEEDS_FILE_PER_TABLE(use_tablespace);
 		CHECK_ERROR_ROW_TYPE_NEEDS_GT_ANTELOPE;
-		/* fall through since dynamic also shuns KBS */
+		/* ROW_FORMAT=DYNAMIC also shuns KEY_BLOCK_SIZE */
+		/* fall through */
 	case ROW_TYPE_COMPACT:
 	case ROW_TYPE_REDUNDANT:
 		if (kbs_specified) {
@@ -10855,7 +10856,8 @@ index_bad:
 			break;
 		}
 		zip_allowed = FALSE;
-		/* fall through to set row_format = COMPACT */
+		/* Set ROW_FORMAT = COMPACT */
+		/* fall through */
 	case ROW_TYPE_NOT_USED:
 	case ROW_TYPE_FIXED:
 	case ROW_TYPE_PAGE:
@@ -10864,6 +10866,7 @@ index_bad:
 			thd, Sql_condition::WARN_LEVEL_WARN,
 			ER_ILLEGAL_HA_CREATE_OPTION,
 			"InnoDB: assuming ROW_FORMAT=COMPACT.");
+		/* fall through */
 	case ROW_TYPE_DEFAULT:
 		/* If we fell through, set row format to Compact. */
 		row_format = ROW_TYPE_COMPACT;
diff --git a/storage/xtradb/include/data0type.ic b/storage/xtradb/include/data0type.ic
index 555852474aa..8f5cee0fd5f 100644
--- a/storage/xtradb/include/data0type.ic
+++ b/storage/xtradb/include/data0type.ic
@@ -576,7 +576,8 @@ dtype_get_fixed_size_low(
 #else /* !UNIV_HOTBACKUP */
 		return(len);
 #endif /* !UNIV_HOTBACKUP */
-		/* fall through for variable-length charsets */
+		/* Treat as variable-length. */
+		/* Fall through */
 	case DATA_VARCHAR:
 	case DATA_BINARY:
 	case DATA_DECIMAL:
diff --git a/storage/xtradb/include/mach0data.ic b/storage/xtradb/include/mach0data.ic
index 4b9275cc12c..26d6c879c9b 100644
--- a/storage/xtradb/include/mach0data.ic
+++ b/storage/xtradb/include/mach0data.ic
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1995, 2009, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -779,13 +780,13 @@ mach_swap_byte_order(
         dest += len;
 
         switch (len & 0x7) {
-        case 0: *--dest = *from++;
-        case 7: *--dest = *from++;
-        case 6: *--dest = *from++;
-        case 5: *--dest = *from++;
-        case 4: *--dest = *from++;
-        case 3: *--dest = *from++;
-        case 2: *--dest = *from++;
+        case 0: *--dest = *from++; /* fall through */
+        case 7: *--dest = *from++; /* fall through */
+        case 6: *--dest = *from++; /* fall through */
+        case 5: *--dest = *from++; /* fall through */
+        case 4: *--dest = *from++; /* fall through */
+        case 3: *--dest = *from++; /* fall through */
+        case 2: *--dest = *from++; /* fall through */
         case 1: *--dest = *from;
         }
 }
diff --git a/storage/xtradb/include/ut0rnd.ic b/storage/xtradb/include/ut0rnd.ic
index 024c59e553b..987dfac03c1 100644
--- a/storage/xtradb/include/ut0rnd.ic
+++ b/storage/xtradb/include/ut0rnd.ic
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1994, 2009, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -237,16 +238,22 @@ ut_fold_binary(
 	switch (len & 0x7) {
 	case 7:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 6:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 5:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 4:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 3:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 2:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
+		/* fall through */
 	case 1:
 		fold = ut_fold_ulint_pair(fold, (ulint)(*str++));
 	}
diff --git a/storage/xtradb/row/row0import.cc b/storage/xtradb/row/row0import.cc
index 23b9ba60269..bc7b5206a64 100644
--- a/storage/xtradb/row/row0import.cc
+++ b/storage/xtradb/row/row0import.cc
@@ -2018,6 +2018,7 @@ PageConverter::update_page(
 	case FIL_PAGE_TYPE_XDES:
 		err = set_current_xdes(
 			buf_block_get_page_no(block), get_frame(block));
+		/* fall through */
 	case FIL_PAGE_INODE:
 	case FIL_PAGE_TYPE_TRX_SYS:
 	case FIL_PAGE_IBUF_FREE_LIST:
diff --git a/storage/xtradb/row/row0log.cc b/storage/xtradb/row/row0log.cc
index 3c5d5773aee..bc40a8f7c05 100644
--- a/storage/xtradb/row/row0log.cc
+++ b/storage/xtradb/row/row0log.cc
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 2011, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -1872,6 +1873,7 @@ row_log_table_apply_update(
 
 		When applying the subsequent ROW_T_DELETE, no matching
 		record will be found. */
+		/* fall through */
 	case DB_SUCCESS:
 		ut_ad(row != NULL);
 		break;
diff --git a/storage/xtradb/row/row0mysql.cc b/storage/xtradb/row/row0mysql.cc
index c0c2b6fbabe..eca26ce9763 100644
--- a/storage/xtradb/row/row0mysql.cc
+++ b/storage/xtradb/row/row0mysql.cc
@@ -5421,7 +5421,8 @@ 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/xtradb/row/row0purge.cc b/storage/xtradb/row/row0purge.cc
index 35b3520749b..d1a7ac2036e 100644
--- a/storage/xtradb/row/row0purge.cc
+++ b/storage/xtradb/row/row0purge.cc
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1997, 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2017, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -488,8 +489,9 @@ row_purge_remove_sec_if_poss_leaf(
 				success = false;
 			}
 		}
-		/* fall through (the index entry is still needed,
+		/* (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/sync/sync0sync.cc b/storage/xtradb/sync/sync0sync.cc
index c270b73e5a0..48cfbf4d6c3 100644
--- a/storage/xtradb/sync/sync0sync.cc
+++ b/storage/xtradb/sync/sync0sync.cc
@@ -1220,6 +1220,7 @@ sync_thread_add_level(
 			upgrading in innobase_start_or_create_for_mysql(). */
 			break;
 		}
+		/* fall through */
 	case SYNC_MEM_POOL:
 	case SYNC_MEM_HASH:
 	case SYNC_RECV:
@@ -1282,9 +1283,9 @@ sync_thread_add_level(
 			}
 		}
 		ut_ad(found_current);
-
-		/* fallthrough */
 	}
+
+		/* fall through */
 	case SYNC_BUF_FLUSH_LIST:
 	case SYNC_BUF_LRU_LIST:
 	case SYNC_BUF_FREE_LIST: