BUG#32288105: MYSQL CRASHES IMMEDIATELY AFTER SELECTING FROM

              INFORMATION_SCHEMA

ISSUE

Queries on tables executed after querying the INFORMATION_SCHEMA
tables INNODB_TABLES, INNODB_COLUMNS, INNODB_INDEXES,
INNODB_TABLESTATS and INNODB_VIRTUAL can trigger an assert on case
insensitive file system where the lower-case-table-names is set to 2.

ROOT CAUSE

When querying the I_S tables, the function dd_table_open_on_dd_obj()
is called to load the table definition from the DD object. However,
if the table was created with a mixed-case schema or table name,
dd_table_open_on_dd_obj() does not convert the name to lowercase
before adding it to dictionary cache. Subsequent queries look up the
cache using the lowercase name, but since the entry was stored with
mixed casing, it is not found. Hence it tries to add to cache using
dict_table_add_to_cache(). During error checks before adding an entry,
the cache is searched using the table id and finds an entry in the cache
triggering an assert.

FIX

The function dd_table_open_on_dd_obj() is modified to convert the name
to lower case before loading the table definition and adding to the
dictionary cache on case insensitive file sytem.

Change-Id: Id902acfc3622b6af869f5b9dc830d0be58cc09c8

Author: Nisha Gopalakrishnan

storage/innobase/dict/dict0dd.cc

@@ -435,39 +435,46 @@ int dd_table_open_on_dd_obj(THD *thd, dd::cache::Dictionary_client *client,
 
   TABLE_SHARE ts;
   TABLE table_def;
-  dd::Schema *schema;
 
   error =
       acquire_uncached_table(thd, client, &dd_table, tbl_name, &ts, &table_def);
   if (error != 0) {
     return (error);
   }
 
-  char tmp_name[MAX_FULL_NAME_LEN + 1];
-  const char *tab_namep;
-  if (tbl_name) {
-    tab_namep = tbl_name;
-  } else {
-    char tmp_schema[MAX_DATABASE_NAME_LEN + 1];
-    char tmp_tablename[MAX_TABLE_NAME_LEN + 1];
+  const char *table_name = tbl_name;
+  if (!tbl_name) {
+    dd::Schema *schema;
     error = client->acquire_uncached<dd::Schema>(dd_table.schema_id(), &schema);
     if (error != 0) {
       return error;
     }
-    tablename_to_filename(schema->name().c_str(), tmp_schema,
-                          MAX_DATABASE_NAME_LEN + 1);
-    tablename_to_filename(dd_table.name().c_str(), tmp_tablename,
-                          MAX_TABLE_NAME_LEN + 1);
-    snprintf(tmp_name, sizeof tmp_name, "%s/%s", tmp_schema, tmp_tablename);
-    tab_namep = tmp_name;
+
+    bool truncated;
+    char tmp_name[FN_REFLEN + 1];
+    build_table_filename(tmp_name, sizeof(tmp_name) - 1, schema->name().c_str(),
+                         dd_table.name().c_str(), nullptr, 0, &truncated);
+
+    if (truncated) {
+      ut_d(ut_error);
+      ut_o(return DB_TOO_LONG_PATH);
+    }
+    table_name = tmp_name;
+  }
+
+  char norm_name[FN_REFLEN];
+  if (!normalize_table_name(norm_name, table_name)) {
+    ut_d(ut_error);
+    ut_o(return DB_TOO_LONG_PATH);
   }
+
   if (dd_part == nullptr) {
-    table = dd_open_table(client, &table_def, tab_namep, &dd_table, thd);
+    table = dd_open_table(client, &table_def, norm_name, &dd_table, thd);
     if (table == nullptr) {
       error = HA_ERR_GENERIC;
     }
   } else {
-    table = dd_open_table(client, &table_def, tab_namep, dd_part, thd);
+    table = dd_open_table(client, &table_def, norm_name, dd_part, thd);
   }
   release_uncached_table(&ts, &table_def);
   return error;