Bug#36234681: InnoDB: Failing assertion: result != FTS_INVALID

ANALYSIS

DELETE operation on a table with self referential foreign key
constraint and full text index may trigger an assert.

When performing the DELETE operation, marking of deletion of the
full text row happens twice due to the self referential foreign
key constraint. Hence the state of the row becomes invalid and
the assert is triggered.

Fix

Avoid updating the full text index if the foreign key has self
referential constraint.

Change-Id: I0c018b63f259b7b1c89c10de8e560d34a63bbd0c

Author: Nisha Gopalakrishnan

storage/innobase/dict/dict0mem.cc

@@ -872,6 +872,28 @@ bool dict_foreign_set_validate(const dict_table_t &table) {
   return (dict_foreign_set_validate(table.foreign_set) &&
           dict_foreign_set_validate(table.referenced_set));
 }
+
+bool dict_foreign_t::is_fts_col_affected() const {
+  /* The check is skipped:
+     - if the table has no full text index defined.
+     - if it is a self referential foreign constaint. This is because
+       in the context of cascading DML operation, only the referenced
+       table is relevant for the validation even if the current table
+       has FTS index.*/
+  if (!foreign_table->fts || foreign_table == referenced_table) {
+    return false;
+  }
+
+  for (ulint i = 0; i < n_fields; i++) {
+    const dict_col_t *col = foreign_index->get_col(i);
+    if (dict_table_is_fts_column(foreign_table->fts->indexes,
+                                 dict_col_get_no(col),
+                                 col->is_virtual()) != ULINT_UNDEFINED) {
+      return true;
+    }
+  }
+  return false;
+}
 #endif /* !UNIV_HOTBACKUP */
 
 std::ostream &operator<<(std::ostream &out, const dict_foreign_t &foreign) {

storage/innobase/include/dict0mem.h

@@ -1698,6 +1698,15 @@ struct dict_foreign_t {
 
   dict_vcol_set *v_cols; /*!< set of virtual columns affected
                          by foreign key constraint. */
+
+  /** Check whether foreign key constraint contains a column with a full
+  index on it. The function is used in the context of cascading DML
+  operations.
+  @retval true  if the column has FTS index on it.
+  @retval false if the FK table has no FTS index or has self referential
+               relationship
+  */
+  bool is_fts_col_affected() const;
 };
 
 std::ostream &operator<<(std::ostream &out, const dict_foreign_t &foreign);

storage/innobase/row/row0ins.cc

@@ -490,7 +490,7 @@ static bool row_ins_cascade_ancestor_updates_table(
 
   n_fields_updated = 0;
 
-  *fts_col_affected = false;
+  *fts_col_affected = foreign->is_fts_col_affected();
 
   if (table->fts) {
     doc_id_pos = dict_table_get_nth_col_pos(table, table->fts->doc_col);
@@ -593,14 +593,6 @@ static bool row_ins_cascade_ancestor_updates_table(
           dfield_set_data(&ufield->new_val, padded_data, min_size);
         }
 
-        /* Check whether the current column has
-        FTS index on it */
-        if (table->fts &&
-            dict_table_is_fts_column(table->fts->indexes, dict_col_get_no(col),
-                                     col->is_virtual()) != ULINT_UNDEFINED) {
-          *fts_col_affected = true;
-        }
-
         /* If Doc ID is updated, check whether the
         Doc ID is valid */
         if (table->fts && ufield->field_no == doc_id_pos) {
@@ -986,7 +978,6 @@ static void row_ins_foreign_fill_virtual(upd_node_t *cascade, const rec_t *rec,
   trx_t *trx;
   mem_heap_t *tmp_heap = nullptr;
   doc_id_t doc_id = FTS_NULL_DOC_ID;
-  bool fts_col_affacted = false;
 
   DBUG_TRACE;
   ut_a(thr);
@@ -1191,16 +1182,9 @@ static void row_ins_foreign_fill_virtual(upd_node_t *cascade, const rec_t *rec,
       ufield->orig_len = 0;
       ufield->exp = nullptr;
       dfield_set_null(&ufield->new_val);
-
-      if (table->fts &&
-          dict_table_is_fts_column(table->fts->indexes, index->get_col_no(i),
-                                   index->get_col(i)->is_virtual()) !=
-              ULINT_UNDEFINED) {
-        fts_col_affacted = true;
-      }
     }
 
-    if (fts_col_affacted) {
+    if (foreign->is_fts_col_affected()) {
       fts_trx_add_op(trx, table, doc_id, FTS_DELETE, nullptr);
     }
 
@@ -1215,26 +1199,18 @@ static void row_ins_foreign_fill_virtual(upd_node_t *cascade, const rec_t *rec,
 
   } else if (table->fts && cascade->is_delete) {
     /* DICT_FOREIGN_ON_DELETE_CASCADE case */
-    for (i = 0; i < foreign->n_fields; i++) {
-      if (table->fts &&
-          dict_table_is_fts_column(table->fts->indexes, index->get_col_no(i),
-                                   index->get_col(i)->is_virtual()) !=
-              ULINT_UNDEFINED) {
-        fts_col_affacted = true;
-      }
-    }
-
-    if (fts_col_affacted) {
+    if (foreign->is_fts_col_affected()) {
       fts_trx_add_op(trx, table, doc_id, FTS_DELETE, nullptr);
     }
   }
 
   if (!node->is_delete && (foreign->type & DICT_FOREIGN_ON_UPDATE_CASCADE)) {
+    bool fts_col_affected = false;
     /* Build the appropriate update vector which sets changing
     foreign->n_fields first fields in rec to new values */
 
     n_to_update = row_ins_cascade_calc_update_vec(node, foreign, tmp_heap, trx,
-                                                  &fts_col_affacted);
+                                                  &fts_col_affected);
 
     if (foreign->v_cols != nullptr && foreign->v_cols->size() > 0) {
       row_ins_foreign_fill_virtual(cascade, clust_rec, clust_index, node,
@@ -1271,7 +1247,7 @@ static void row_ins_foreign_fill_virtual(upd_node_t *cascade, const rec_t *rec,
     }
 
     /* Mark the old Doc ID as deleted */
-    if (fts_col_affacted) {
+    if (fts_col_affected) {
       ut_ad(table->fts);
       fts_trx_add_op(trx, table, doc_id, FTS_DELETE, nullptr);
     }