cleanup: InnoDB, remove index_field_t::col_name

* remnant of 5.6, does not exist in 5.7. bad merge?
* also remove dict_table_get_col_name_for_mysql(), it was only
  used when index_field_t::col_name was not NULL

storage/innobase/dict/dict0dict.cc

@@ -654,41 +654,6 @@ dict_table_get_col_name(
 	return(s);
 }
 
-/**********************************************************************//**
-Returns a column's name.
-@return column name. NOTE: not guaranteed to stay valid if table is
-modified in any way (columns added, etc.). */
-UNIV_INTERN
-const char*
-dict_table_get_col_name_for_mysql(
-/*==============================*/
-	const dict_table_t*	table,	/*!< in: table */
-	const char*		col_name)/*! in: MySQL table column name */
-{
-	ulint		i;
-	const char*	s;
-
-	ut_ad(table);
-	ut_ad(col_name);
-	ut_ad(table->magic_n == DICT_TABLE_MAGIC_N);
-
-	s = table->col_names;
-	if (s) {
-		/* If we have many virtual columns MySQL key_part->fieldnr
-		could be larger than number of columns in InnoDB table
-		when creating new indexes. */
-		for (i = 0; i < table->n_def; i++) {
-
-			if (!innobase_strcasecmp(s, col_name)) {
-				break; /* Found */
-			}
-			s += strlen(s) + 1;
-		}
-	}
-
-	return(s);
-}
-
 /** Returns a virtual column's name.
 @param[in]	table	target table
 @param[in]	col_nr	virtual column number (nth virtual column)

storage/innobase/handler/handler0alter.cc

@@ -2183,7 +2183,6 @@ innobase_create_index_field_def(
 #else
 	index_field->is_v_col = false;
 	index_field->col_no = key_part->fieldnr - num_m_v;
-	index_field->col_name = altered_table ? field->field_name : fields[key_part->fieldnr]->field_name;
 #endif /* MYSQL_VIRTUAL_COLUMNS */
 
 	if (DATA_LARGE_MTYPE(col_type)

storage/innobase/include/dict0dict.h

@@ -613,18 +613,6 @@ dict_table_get_col_name(
 	ulint			col_nr)	/*!< in: column number */
 	MY_ATTRIBUTE((nonnull, warn_unused_result));
 
-/**********************************************************************//**
-Returns a column's name.
-@return column name. NOTE: not guaranteed to stay valid if table is
-modified in any way (columns added, etc.). */
-UNIV_INTERN
-const char*
-dict_table_get_col_name_for_mysql(
-/*==============================*/
-	const dict_table_t*	table,	/*!< in: table */
-	const char*		col_name)/*!< in: MySQL table column name */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
-
 /** Returns a virtual column's name.
 @param[in]	table		table object
 @param[in]	col_nr		virtual column number(nth virtual column)

storage/innobase/include/row0merge.h

@@ -114,7 +114,6 @@ struct index_field_t {
 	ulint		col_no;		/*!< column offset */
 	ulint		prefix_len;	/*!< column prefix length, or 0
 					if indexing the whole column */
-	const char*	col_name;	/*!< column name or NULL */
 	bool		is_v_col;	/*!< whether this is a virtual column */
 };
 

storage/innobase/row/row0merge.cc

@@ -4509,9 +4509,7 @@ row_merge_create_index(
 			if (col_names && col_names[i]) {
 				name = col_names[i];
 			} else {
-				name = ifield->col_name ?
-					dict_table_get_col_name_for_mysql(table, ifield->col_name) :
-					dict_table_get_col_name(table, ifield->col_no);
+				name = dict_table_get_col_name(table, ifield->col_no);
 			}
 		}