hint: fix panic when query block not found in prepare statement (#46818…

…) (#46842) close #46817
pingcap · Oct 18, 2023 · 288af37 · 288af37
1 parent 60b4dcc
commit 288af37
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/executor/prepared_test.go b/executor/prepared_test.go
@@ -96,6 +96,11 @@ func TestPreparedStmtWithHint(t *testing.T) {
 	go dom.ExpensiveQueryHandle().SetSessionManager(sv).Run()
 	tk.MustExec("prepare stmt from \"select /*+ max_execution_time(100) */ sleep(10)\"")
 	tk.MustQuery("execute stmt").Check(testkit.Rows("1"))
+
+	// see https://github.com/pingcap/tidb/issues/46817
+	tk.MustExec("use test")
+	tk.MustExec("create table if not exists t (i int)")
+	tk.MustExec("prepare stmt from 'with a as (select /*+ qb_name(qb1) */ * from t)  select /*+ leading(@qb1)*/ * from a;'")
 }
 
 func TestPreparedNullParam(t *testing.T) {

diff --git a/util/hint/hint_processor.go b/util/hint/hint_processor.go
@@ -595,8 +595,10 @@ func (p *BlockHintProcessor) GetCurrentStmtHints(hints []*ast.TableOptimizerHint
 		}
 		offset := p.GetHintOffset(hint.QBName, currentOffset)
 		if offset < 0 || !p.checkTableQBName(hint.Tables) {
-			hintStr := RestoreTableOptimizerHint(hint)
-			p.Ctx.GetSessionVars().StmtCtx.AppendWarning(fmt.Errorf("Hint %s is ignored due to unknown query block name", hintStr))
+			if p.Ctx != nil {
+				hintStr := RestoreTableOptimizerHint(hint)
+				p.Ctx.GetSessionVars().StmtCtx.AppendWarning(fmt.Errorf("Hint %s is ignored due to unknown query block name", hintStr))
+			}
 			continue
 		}
 		p.QbHints[offset] = append(p.QbHints[offset], hint)