MDEV-16267 Wrong INFORMATION_SCHEMA.INNODB_BUFFER_PAGE.TABLE_NAME

This is the MariaDB 10.2 version of the patch.

field_store_string(): Simplify the code.

field_store_index_name(): Remove, and use field_store_string()
instead. Starting with MariaDB 10.2.2, there is the predicate
dict_index_t::is_committed(), and dict_index_t::name never
contains the magic byte 0xff.

Correct some comments to refer to TEMP_INDEX_PREFIX_STR.

i_s_cmp_per_index_fill_low(): Use the appropriate value NULL to
identify that an index was not found. Check that storing each
column value succeeded.

i_s_innodb_buffer_page_fill(), i_s_innodb_buf_page_lru_fill():
Only invoke Field::set_notnull() if the index was found.
(This fixes the bug.)

i_s_dict_fill_sys_indexes(): Adjust the index->name that was
directly loaded from SYS_INDEXES.NAME (which can start with
the 0xff byte). This was the only function that depended
on the translation in field_store_index_name().

storage/innobase/dict/dict0load.cc

@@ -2477,8 +2477,9 @@ dict_load_indexes(
 			    && static_cast<char>(*field)
 			    == static_cast<char>(*TEMP_INDEX_PREFIX_STR)) {
 				/* Skip indexes whose name starts with
-				TEMP_INDEX_PREFIX, because they will
-				be dropped during crash recovery. */
+				TEMP_INDEX_PREFIX_STR, because they will
+				be dropped by row_merge_drop_temp_indexes()
+				during crash recovery. */
 				goto next_rec;
 			}
 		}

storage/innobase/handler/handler0alter.cc

@@ -8169,7 +8169,7 @@ commit_cache_norebuild(
 		(after renaming the indexes), so that in the
 		event of a crash, crash recovery will drop the
 		indexes, because it drops all indexes whose
-		names start with TEMP_INDEX_PREFIX. Once we
+		names start with TEMP_INDEX_PREFIX_STR. Once we
 		have started dropping an index tree, there is
 		no way to roll it back. */
 

storage/innobase/handler/i_s.cc

@@ -261,59 +261,13 @@ field_store_string(
 	const char*	str)	/*!< in: NUL-terminated utf-8 string,
 				or NULL */
 {
-	int	ret;
-
-	if (str != NULL) {
-
-		ret = field->store(str, static_cast<uint>(strlen(str)),
-				   system_charset_info);
-		field->set_notnull();
-	} else {
-
-		ret = 0; /* success */
+	if (!str) {
 		field->set_null();
-	}
-
-	return(ret);
-}
-
-/*******************************************************************//**
-Store the name of an index in a MYSQL_TYPE_VARCHAR field.
-Handles the names of incomplete secondary indexes.
-@return 0 on success */
-static
-int
-field_store_index_name(
-/*===================*/
-	Field*		field,		/*!< in/out: target field for
-					storage */
-	const char*	index_name)	/*!< in: NUL-terminated utf-8
-					index name, possibly starting with
-					TEMP_INDEX_PREFIX */
-{
-	int	ret;
-
-	ut_ad(index_name != NULL);
-	ut_ad(field->real_type() == MYSQL_TYPE_VARCHAR);
-
-	/* Since TEMP_INDEX_PREFIX is not a valid UTF8, we need to convert
-	it to something else. */
-	if (*index_name == *TEMP_INDEX_PREFIX_STR) {
-		char	buf[NAME_LEN + 1];
-		buf[0] = '?';
-		memcpy(buf + 1, index_name + 1, strlen(index_name));
-		ret = field->store(
-			buf, static_cast<uint>(strlen(buf)),
-			system_charset_info);
-	} else {
-		ret = field->store(
-			index_name, static_cast<uint>(strlen(index_name)),
-			system_charset_info);
+		return 0;
 	}
 
 	field->set_notnull();
-
-	return(ret);
+	return field->store(str, uint(strlen(str)), system_charset_info);
 }
 
 /*******************************************************************//**
@@ -952,12 +906,8 @@ fill_innodb_locks_from_cache(
 			buf, uint(bufend - buf), system_charset_info));
 
 		/* lock_index */
-		if (row->lock_index != NULL) {
-			OK(field_store_index_name(fields[IDX_LOCK_INDEX],
+		OK(field_store_string(fields[IDX_LOCK_INDEX],
 				      row->lock_index));
-		} else {
-			fields[IDX_LOCK_INDEX]->set_null();
-		}
 
 		/* lock_space */
 		OK(field_store_ulint(fields[IDX_LOCK_SPACE],
@@ -1731,7 +1681,6 @@ i_s_cmp_per_index_fill_low(
 
 	for (iter = snap.begin(), i = 0; iter != snap.end(); iter++, i++) {
 
-		char		name[192];
 		dict_index_t*	index = dict_index_find_on_id_low(iter->first);
 
 		if (index != NULL) {
@@ -1742,38 +1691,39 @@ i_s_cmp_per_index_fill_low(
 				     db_utf8, sizeof(db_utf8),
 				     table_utf8, sizeof(table_utf8));
 
-			field_store_string(fields[IDX_DATABASE_NAME], db_utf8);
-			field_store_string(fields[IDX_TABLE_NAME], table_utf8);
-			field_store_index_name(fields[IDX_INDEX_NAME],
+			status = field_store_string(fields[IDX_DATABASE_NAME],
+						    db_utf8)
+				|| field_store_string(fields[IDX_TABLE_NAME],
+						      table_utf8)
+				|| field_store_string(fields[IDX_INDEX_NAME],
 						      index->name);
 		} else {
 			/* index not found */
-			snprintf(name, sizeof(name),
-				 "index_id:" IB_ID_FMT, iter->first);
-			field_store_string(fields[IDX_DATABASE_NAME],
-					   "unknown");
-			field_store_string(fields[IDX_TABLE_NAME],
-					   "unknown");
-			field_store_string(fields[IDX_INDEX_NAME],
-					   name);
+			char name[MY_INT64_NUM_DECIMAL_DIGITS
+				  + sizeof "index_id: "];
+			fields[IDX_DATABASE_NAME]->set_null();
+			fields[IDX_TABLE_NAME]->set_null();
+			fields[IDX_INDEX_NAME]->set_notnull();
+			status = fields[IDX_INDEX_NAME]->store(
+				name,
+				uint(snprintf(name, sizeof name,
+					      "index_id: " IB_ID_FMT,
+					      iter->first)),
+				system_charset_info);
 		}
 
-		fields[IDX_COMPRESS_OPS]->store(
-			   iter->second.compressed, true);
-
-		fields[IDX_COMPRESS_OPS_OK]->store(
-			   iter->second.compressed_ok, true);
-
-		fields[IDX_COMPRESS_TIME]->store(
-			   iter->second.compressed_usec / 1000000, true);
-
-		fields[IDX_UNCOMPRESS_OPS]->store(
-			   iter->second.decompressed, true);
-
-		fields[IDX_UNCOMPRESS_TIME]->store(
-			   iter->second.decompressed_usec / 1000000, true);
-
-		if (schema_table_store_record(thd, table)) {
+		if (status
+		    || fields[IDX_COMPRESS_OPS]->store(
+			    iter->second.compressed, true)
+		    || fields[IDX_COMPRESS_OPS_OK]->store(
+			    iter->second.compressed_ok, true)
+		    || fields[IDX_COMPRESS_TIME]->store(
+			    iter->second.compressed_usec / 1000000, true)
+		    || fields[IDX_UNCOMPRESS_OPS]->store(
+			    iter->second.decompressed, true)
+		    || fields[IDX_UNCOMPRESS_TIME]->store(
+			    iter->second.decompressed_usec / 1000000, true)
+		    || schema_table_store_record(thd, table)) {
 			status = 1;
 			break;
 		}
@@ -1781,8 +1731,9 @@ i_s_cmp_per_index_fill_low(
 		threads to proceed. This could eventually result in the
 		contents of INFORMATION_SCHEMA.innodb_cmp_per_index being
 		inconsistent, but it is an acceptable compromise. */
-		if (i % 1000 == 0) {
+		if (i == 1000) {
 			mutex_exit(&dict_sys->mutex);
+			i = 0;
 			mutex_enter(&dict_sys->mutex);
 		}
 	}
@@ -4932,9 +4883,11 @@ i_s_innodb_buffer_page_fill(
 
 			mutex_enter(&dict_sys->mutex);
 
-			if (const dict_index_t*	index =
+			const dict_index_t* index =
 				dict_index_get_if_in_cache_low(
-				    page_info->index_id)) {
+					page_info->index_id);
+
+			if (index) {
 				table_name_end = innobase_convert_name(
 					table_name, sizeof(table_name),
 					index->table_name,
@@ -4947,17 +4900,22 @@ i_s_innodb_buffer_page_fill(
 							table_name_end
 							- table_name),
 						system_charset_info)
-					|| field_store_index_name(
-						fields
-						[IDX_BUFFER_PAGE_INDEX_NAME],
-						index->name);
+					|| fields[IDX_BUFFER_PAGE_INDEX_NAME]
+					->store(index->name,
+						uint(strlen(index->name)),
+						system_charset_info);
 			}
 
 			mutex_exit(&dict_sys->mutex);
 
 			OK(ret);
 
-			fields[IDX_BUFFER_PAGE_TABLE_NAME]->set_notnull();
+			if (index) {
+				fields[IDX_BUFFER_PAGE_TABLE_NAME]
+					->set_notnull();
+				fields[IDX_BUFFER_PAGE_INDEX_NAME]
+					->set_notnull();
+			}
 		}
 
 		OK(fields[IDX_BUFFER_PAGE_NUM_RECS]->store(
@@ -5649,9 +5607,11 @@ i_s_innodb_buf_page_lru_fill(
 
 			mutex_enter(&dict_sys->mutex);
 
-			if (const dict_index_t* index =
+			const dict_index_t* index =
 				dict_index_get_if_in_cache_low(
-				    page_info->index_id)) {
+					page_info->index_id);
+
+			if (index) {
 				table_name_end = innobase_convert_name(
 					table_name, sizeof(table_name),
 					index->table_name,
@@ -5664,17 +5624,22 @@ i_s_innodb_buf_page_lru_fill(
 							table_name_end
 							- table_name),
 						system_charset_info)
-					|| field_store_index_name(
-						fields
-						[IDX_BUF_LRU_PAGE_INDEX_NAME],
-						index->name);
+					|| fields[IDX_BUF_LRU_PAGE_INDEX_NAME]
+					->store(index->name,
+						uint(strlen(index->name)),
+						system_charset_info);
 			}
 
 			mutex_exit(&dict_sys->mutex);
 
 			OK(ret);
 
-			fields[IDX_BUF_LRU_PAGE_TABLE_NAME]->set_notnull();
+			if (index) {
+				fields[IDX_BUF_LRU_PAGE_TABLE_NAME]
+					->set_notnull();
+				fields[IDX_BUF_LRU_PAGE_INDEX_NAME]
+					->set_notnull();
+			}
 		}
 
 		OK(fields[IDX_BUF_LRU_PAGE_NUM_RECS]->store(
@@ -6647,7 +6612,15 @@ i_s_dict_fill_sys_indexes(
 
 	fields = table_to_fill->field;
 
-	OK(field_store_index_name(fields[SYS_INDEX_NAME], index->name));
+	if (*index->name == *TEMP_INDEX_PREFIX_STR) {
+		/* Since TEMP_INDEX_PREFIX_STR is not valid UTF-8, we
+		need to convert it to something else. */
+		*const_cast<char*>(index->name()) = '?';
+	}
+
+	OK(fields[SYS_INDEX_NAME]->store(index->name,
+					 uint(strlen(index->name)),
+					 system_charset_info));
 
 	OK(fields[SYS_INDEX_ID]->store(longlong(index->id), true));