From 23796a46a0710f1cf25ae631d3e058d9f197c844 Mon Sep 17 00:00:00 2001
From: Ti Chi Robot <ti-community-prow-bot@tidb.io>
Date: Mon, 11 Dec 2023 11:58:48 +0800
Subject: [PATCH] ddl: fix recover table by JobID bug when JobID is set to 0
 tidb-server panic (#46343) (#48086)

close pingcap/tidb#46296
---
 executor/ddl.go          | 7 ++++---
 executor/recover_test.go | 5 +++++
 parser/ast/ddl.go        | 8 ++++----
 parser/parser_test.go    | 1 +
 4 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/executor/ddl.go b/executor/ddl.go
index 7dc2ab47de971..5b7556ef7b97e 100644
--- a/executor/ddl.go
+++ b/executor/ddl.go
@@ -392,10 +392,11 @@ func (e *DDLExec) executeRecoverTable(s *ast.RecoverTableStmt) error {
 	var job *model.Job
 	var err error
 	var tblInfo *model.TableInfo
-	if s.JobID != 0 {
-		job, tblInfo, err = e.getRecoverTableByJobID(s, dom)
-	} else {
+	// Let check table first. Related isssue #46296.
+	if s.Table != nil {
 		job, tblInfo, err = e.getRecoverTableByTableName(s.Table)
+	} else {
+		job, tblInfo, err = e.getRecoverTableByJobID(s, dom)
 	}
 	if err != nil {
 		return err
diff --git a/executor/recover_test.go b/executor/recover_test.go
index 0b8c342b1111c..27d20c24a1600 100644
--- a/executor/recover_test.go
+++ b/executor/recover_test.go
@@ -92,6 +92,11 @@ func TestRecoverTable(t *testing.T) {
 	err := tk.ExecToErr(fmt.Sprintf("recover table by job %d", 10000000))
 	require.Error(t, err)
 
+	// recover table by zero JobID.
+	// related issue: https://github.com/pingcap/tidb/issues/46296
+	err = tk.ExecToErr(fmt.Sprintf("recover table by job %d", 0))
+	require.Error(t, err)
+
 	// Disable GC by manual first, then after recover table, the GC enable status should also be disabled.
 	require.NoError(t, gcutil.DisableGC(tk.Session()))
 
diff --git a/parser/ast/ddl.go b/parser/ast/ddl.go
index 03f07ac194ff4..8f2ad83946d5d 100644
--- a/parser/ast/ddl.go
+++ b/parser/ast/ddl.go
@@ -4228,16 +4228,16 @@ type RecoverTableStmt struct {
 // Restore implements Node interface.
 func (n *RecoverTableStmt) Restore(ctx *format.RestoreCtx) error {
 	ctx.WriteKeyWord("RECOVER TABLE ")
-	if n.JobID != 0 {
-		ctx.WriteKeyWord("BY JOB ")
-		ctx.WritePlainf("%d", n.JobID)
-	} else {
+	if n.Table != nil {
 		if err := n.Table.Restore(ctx); err != nil {
 			return errors.Annotate(err, "An error occurred while splicing RecoverTableStmt Table")
 		}
 		if n.JobNum > 0 {
 			ctx.WritePlainf(" %d", n.JobNum)
 		}
+	} else {
+		ctx.WriteKeyWord("BY JOB ")
+		ctx.WritePlainf("%d", n.JobID)
 	}
 	return nil
 }
diff --git a/parser/parser_test.go b/parser/parser_test.go
index 91ee4c4b1c68c..2b4847afb72d7 100644
--- a/parser/parser_test.go
+++ b/parser/parser_test.go
@@ -3311,6 +3311,7 @@ func TestDDL(t *testing.T) {
 		{"recover table by job 11", true, "RECOVER TABLE BY JOB 11"},
 		{"recover table by job 11,12,13", false, ""},
 		{"recover table by job", false, ""},
+		{"recover table by job 0", true, "RECOVER TABLE BY JOB 0"},
 		{"recover table t1", true, "RECOVER TABLE `t1`"},
 		{"recover table t1,t2", false, ""},
 		{"recover table ", false, ""},