keyspace: address review comments for group removal

Signed-off-by: bufferflies <1045931706@qq.com>

Author: bufferflies

pkg/keyspace/tso_keyspace_group.go

@@ -445,6 +445,12 @@ func (m *GroupManager) RemoveKeyspacesFromGroup(groupID uint32, keyspaceIDs []ui
 		if kg == nil {
 			return errs.ErrKeyspaceGroupNotExists.FastGenByArgs(groupID)
 		}
+		if kg.IsSplitting() {
+			return errs.ErrKeyspaceGroupInSplit.FastGenByArgs(groupID)
+		}
+		if kg.IsMerging() {
+			return errs.ErrKeyspaceGroupInMerging.FastGenByArgs(groupID)
+		}
 
 		// Build a set of keyspaces to remove (excluding default keyspace)
 		toRemove := make(map[uint32]struct{})

server/apiv2/handlers/tso_keyspace_group.go

@@ -579,7 +579,7 @@ func RemoveKeyspacesFromGroup(c *gin.Context) {
 	// Parse request body
 	var params RemoveKeyspacesFromGroupParams
 	if err := c.BindJSON(&params); err != nil {
-		c.AbortWithStatusJSON(http.StatusBadRequest, errs.ErrBindJSON.Wrap(err).GenWithStackByCause())
+		c.AbortWithStatusJSON(http.StatusBadRequest, errs.ErrBindJSON.Wrap(err).GenWithStackByCause().Error())
 		return
 	}
 
@@ -629,6 +629,10 @@ func RemoveKeyspacesFromGroup(c *gin.Context) {
 			c.AbortWithStatusJSON(http.StatusInternalServerError, err.Error())
 			return
 		}
+		if kg == nil {
+			c.AbortWithStatusJSON(http.StatusInternalServerError, errs.ErrKeyspaceGroupNotExists.FastGenByArgs(groupID).Error())
+			return
+		}
 		c.IndentedJSON(http.StatusOK, kg)
 		return
 	}

tests/server/apiv2/handlers/tso_keyspace_group_test.go

@@ -274,7 +274,9 @@ func (suite *keyspaceGroupTestSuite) TestKeyspaceGroupErrorMessage() {
 func (suite *keyspaceGroupTestSuite) TestRemoveKeyspacesFromGroup() {
 	re := suite.Require()
 	re.NoError(failpoint.Enable("github.com/tikv/pd/server/delayStartServerLoop", `return(true)`))
+	defer re.NoError(failpoint.Disable("github.com/tikv/pd/server/delayStartServerLoop"))
 	re.NoError(failpoint.Enable("github.com/tikv/pd/pkg/keyspace/skipSplitRegion", "return(true)"))
+	defer re.NoError(failpoint.Disable("github.com/tikv/pd/pkg/keyspace/skipSplitRegion"))
 
 	keyspaceManager := suite.server.GetKeyspaceManager()
 	re.NotNil(keyspaceManager)