MDEV-34953 followup - allow Innodb to work with old data dictionary without upgrade.

Previously, Innodb used partition separator "#p#" on Windows,
and "#P#" elsewhere. Now it uses "#P#" uniformly,

Yet, there is no automated upgrade procedure yet in place that would fix
old data dictionary.

This patch fixed it, by accepting both #P# and #p# as partition
separators.

Author: vaintroub

storage/innobase/dict/dict0mem.cc

@@ -73,10 +73,6 @@ static bool dict_mem_table_is_system(const char *name)
 	return false;
 }
 
-/** The start of the table basename suffix for partitioned tables */
-const char table_name_t::part_suffix[4]
-= "#P#";
-
 /** Display an identifier.
 @param[in,out]	s	output stream
 @param[in]	id_name	SQL identifier (other than table name)
@@ -1372,3 +1368,23 @@ dict_index_t::vers_history_row(
 	mtr->rollback_to_savepoint(sp);
 	return(error);
 }
+
+/** Checks whether the file name belongs to a partition of a table.
+@param	file_name	file name
+@return pointer to the end of the table name part of the file name
+@retval nullptr  if the file name does not belong to a partition. */
+const char *dict_is_partition(const char *file_name)
+{
+  /* We look for pattern #P# to see if the table is partitioned
+  MariaDB table. We also look for #p# pattern, because it was
+  previously used on Windows. */
+  for (const char *p= file_name;; p++)
+  {
+    p= strchr(p, '#');
+    if (!p)
+      break;
+    if ((p[1] == 'P' || p[1] == 'p') && p[2] == '#')
+      return p;
+  }
+  return nullptr;
+}

storage/innobase/handler/ha_innodb.cc

@@ -259,20 +259,6 @@ void set_my_errno(int err)
 	errno = err;
 }
 
-/** Checks whether the file name belongs to a partition of a table.
-@param[in]	file_name	file name
-@return pointer to the end of the table name part of the file name, or NULL */
-static
-char*
-is_partition(
-/*=========*/
-	char*		file_name)
-{
-	/* We look for pattern #P# to see if the table is partitioned
-	MariaDB table. */
-	return strstr(file_name, table_name_t::part_suffix);
-}
-
 
 
 /** Return the InnoDB ROW_FORMAT enum value
@@ -5114,15 +5100,9 @@ ha_innobase::table_cache_type()
 /** Normalizes a table name string.
 A normalized name consists of the database name catenated to '/'
 and table name. For example: test/mytable.
-@param[out]	norm_name	Normalized name, null-terminated.
-@param[in]	name		Name to normalize */
-void
-normalize_table_name(
-/*=======================*/
-	char*           norm_name,      /* out: normalized name as a
-					null-terminated string */
-	const char*     name          /* in: table name string */
-)
+@param	norm_name	Normalized name, null-terminated.
+@param	name		Name to normalize */
+void normalize_table_name(char* norm_name, const char* name)
 {
 	char*	name_ptr;
 	ulint	name_len;
@@ -5801,8 +5781,8 @@ ha_innobase::open(const char* name, int, uint)
 	m_upd_buf_size = 0;
 	m_disable_rowid_filter = false;
 
-	char*	is_part = is_partition(norm_name);
-	THD*	thd = ha_thd();
+	const char* is_part = dict_is_partition(norm_name);
+	THD* thd = ha_thd();
 	dict_table_t* ib_table = open_dict_table(name, norm_name, is_part,
 						 DICT_ERR_IGNORE_FK_NOKEY);
 
@@ -6131,7 +6111,14 @@ ha_innobase::open_dict_table(
 			ib_table = dict_table_open_on_name(
 				par_case_name, false, ignore_err);
 		}
-
+#ifdef _WIN32
+		/*
+		Omit the warning below, we know we used to convert
+		#P# to lowercase on Windows (we do not do that anymore).
+		Mostly likely, we have a partitioned table from an
+		older MariaDB version.
+		*/
+#else
 		if (ib_table != NULL) {
 			sql_print_warning("Partition table %s opened"
 					  " after converting to lower"
@@ -6142,6 +6129,7 @@ ha_innobase::open_dict_table(
 					  " the current file system\n",
 					  norm_name);
 		}
+#endif
 	}
 
 	DBUG_RETURN(ib_table);
@@ -13552,7 +13540,7 @@ int ha_innobase::delete_table(const char *name)
     dict_sys.lock(SRW_LOCK_CALL);
     table= dict_sys.load_table(n, DICT_ERR_IGNORE_DROP);
 #ifdef WITH_PARTITION_STORAGE_ENGINE
-    if (!table && lower_case_table_names == 1 && is_partition(norm_name))
+    if (!table && lower_case_table_names == 1 && dict_is_partition(norm_name))
     {
       my_casedn_str(system_charset_info, norm_name);
       table= dict_sys.load_table(n, DICT_ERR_IGNORE_DROP);
@@ -13825,7 +13813,7 @@ static dberr_t innobase_rename_table(trx_t *trx, const char *from,
 	if (error != DB_SUCCESS) {
 		if (error == DB_TABLE_NOT_FOUND
 		    && lower_case_table_names == 1) {
-			char*	is_part = is_partition(norm_from);
+			const char* is_part = dict_is_partition(norm_from);
 
 			if (is_part) {
 				char	par_case_name[FN_REFLEN];
@@ -20247,11 +20235,11 @@ innobase_rename_vc_templ(
 
 	/* For partition table, remove the partition name and use the
 	"main" table name to build the template */
-	char*	is_part = is_partition(tbname);
+	const char* is_part = dict_is_partition(tbname);
 
 	if (is_part != NULL) {
-		*is_part = '\0';
 		tbnamelen = ulint(is_part - tbname);
+		tbname[tbnamelen]= 0;
 	}
 
 	dbnamelen = filename_to_tablename(dbname, t_dbname,

storage/innobase/include/dict0types.h

@@ -94,6 +94,13 @@ enum ib_quiesce_t {
 /** Prefix for InnoDB internal tables, adopted from sql/table.h */
 #define TEMP_FILE_PREFIX_INNODB		"#sql-ib"
 
+/** Checks whether the file name belongs to a partition of a table.
+@param	file_name	file name
+@return pointer to the end of the table name part of the file name
+@retval nullptr  if the file name does not belong to a partition. */
+const char *dict_is_partition(const char *file_name);
+
+
 /** Table name wrapper for pretty-printing */
 struct table_name_t
 {
@@ -128,14 +135,10 @@ struct table_name_t
 		return UNIV_LIKELY(end != nullptr) ? end + 1 : nullptr;
 	}
 
-	/** The start of the table basename suffix for partitioned tables */
-	static const char part_suffix[4];
-
 	/** Determine the partition or subpartition name suffix.
 	@return the partition name
 	@retval	NULL	if the table is not partitioned */
-	const char* part() const { return strstr(basename(), part_suffix); }
-
+	const char* part() const { return dict_is_partition(basename()); }
 	/** @return whether this is a temporary or intermediate table name */
 	inline bool is_temporary() const;
 };

storage/innobase/include/ha_prototypes.h

@@ -376,18 +376,12 @@ ib_foreign_warn(
 	const char	*format,/*!< in: warning message */
 	...);
 
-/*****************************************************************//**
-Normalizes a table name string. A normalized name consists of the
-database name catenated to '/' and table name. An example:
-test/mytable. On Windows normalization puts both the database name and the
-table name always to lower case if "set_lower_case" is set to TRUE. */
-void
-normalize_table_name(
-/*=======================*/
-	char*		norm_name,	/*!< out: normalized name as a
-					null-terminated string */
-	const char*	name		/*!< in: table name string */
-);
+/** Normalizes a table name string.
+A normalized name consists of the database name catenated to '/'
+and table name. For example: test/mytable.
+@param	norm_name	Normalized name, null-terminated.
+@param	name		Name to normalize */
+void normalize_table_name(char* norm_name,	const char*	name);
 
 /** Create a MYSQL_THD for a background thread and mark it as such.
 @param name thread info for SHOW PROCESSLIST

storage/innobase/row/row0mysql.cc

@@ -2568,22 +2568,14 @@ row_rename_table_for_mysql(
 
 	/* MariaDB partition engine hard codes the file name
 	separator as "#P#" and "#SP#". The text case is fixed even if
-	lower_case_table_names is set to 1 or 2. InnoDB always
-	normalises file names to lower case on Windows, this
+	lower_case_table_names is set to 1 or 2. InnoDB used to
+	normalize file names to lower case on Windows, this
 	can potentially cause problems when copying/moving
-	tables between platforms.
-
-	1) If boot against an installation from Windows
-	platform, then its partition table name could
-	be all be in lower case in system tables. So we
-	will need to check lower case name when load table.
-
-	2) If  we boot an installation from other case
-	sensitive platform in Windows, we might need to
-	check the existence of table name without lowering
-	case them in the system table. */
+	tables between platforms, even if lower_case_table_names=1
+	was set on both platforms.
+	*/
 	if (!table && lower_case_table_names == 1
-	    && strstr(old_name, table_name_t::part_suffix)) {
+	    && dict_is_partition(old_name)) {
 		char par_case_name[MAX_FULL_NAME_LEN + 1];
 		/* Check for the table using lower
 		case name, including the partition