GetFeeds must always discard actions with dangling repo_id (#19598)

* GetFeeds must always discard actions with dangling repo_id

See https://discourse.gitea.io/t/blank-page-after-login/5051/12
for a panic in 1.16.6.

* add comment to explain the dangling ID in the fixture

* loadRepoOwner must not attempt to use a nil action.Repo

* make fmt

Co-authored-by: Loïc Dachary <loic@dachary.org>

5 files changed, 37 insertions, 7 deletions

diff --git a/models/action.go b/models/action.go
index 5177616497..efbe243bed 100644
--- a/models/action.go
+++ b/models/action.go
@@ -340,14 +340,14 @@ func GetFeeds(ctx context.Context, opts GetFeedsOptions) (ActionList, error) {
 	}
 
 	e := db.GetEngine(ctx)
-	sess := e.Where(cond)
+	sess := e.Where(cond).Join("INNER", "repository", "`repository`.id = `action`.repo_id")
 
 	opts.SetDefaultValues()
 	sess = db.SetSessionPagination(sess, &opts)
 
 	actions := make([]*Action, 0, opts.PageSize)
 
-	if err := sess.Desc("created_unix").Find(&actions); err != nil {
+	if err := sess.Desc("`action`.created_unix").Find(&actions); err != nil {
 		return nil, fmt.Errorf("Find: %v", err)
 	}
 
@@ -417,7 +417,7 @@ func activityQueryCondition(opts GetFeedsOptions) (builder.Cond, error) {
 	}
 
 	if !opts.IncludePrivate {
-		cond = cond.And(builder.Eq{"is_private": false})
+		cond = cond.And(builder.Eq{"`action`.is_private": false})
 	}
 	if !opts.IncludeDeleted {
 		cond = cond.And(builder.Eq{"is_deleted": false})
@@ -430,8 +430,8 @@ func activityQueryCondition(opts GetFeedsOptions) (builder.Cond, error) {
 		} else {
 			dateHigh := dateLow.Add(86399000000000) // 23h59m59s
 
-			cond = cond.And(builder.Gte{"created_unix": dateLow.Unix()})
-			cond = cond.And(builder.Lte{"created_unix": dateHigh.Unix()})
+			cond = cond.And(builder.Gte{"`action`.created_unix": dateLow.Unix()})
+			cond = cond.And(builder.Lte{"`action`.created_unix": dateHigh.Unix()})
 		}
 	}
 
diff --git a/models/action_list.go b/models/action_list.go
index c180a82552..5f7b17b9de 100644
--- a/models/action_list.go
+++ b/models/action_list.go
@@ -80,6 +80,9 @@ func (actions ActionList) loadRepoOwner(e db.Engine, userMap map[int64]*user_mod
 	}
 
 	for _, action := range actions {
+		if action.Repo == nil {
+			continue
+		}
 		repoOwner, ok := userMap[action.Repo.OwnerID]
 		if !ok {
 			repoOwner, err = user_model.GetUserByID(action.Repo.OwnerID)
diff --git a/models/action_test.go b/models/action_test.go
index e247a5ec29..fb8a6c2686 100644
--- a/models/action_test.go
+++ b/models/action_test.go
@@ -211,3 +211,20 @@ func TestNotifyWatchers(t *testing.T) {
 		OpType:    action.OpType,
 	})
 }
+
+func TestGetFeedsCorrupted(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+	user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 1}).(*user_model.User)
+	unittest.AssertExistsAndLoadBean(t, &Action{
+		ID:     8,
+		RepoID: 1700,
+	})
+
+	actions, err := GetFeeds(db.DefaultContext, GetFeedsOptions{
+		RequestedUser:  user,
+		Actor:          user,
+		IncludePrivate: true,
+	})
+	assert.NoError(t, err)
+	assert.Len(t, actions, 0)
+}
diff --git a/models/fixtures/action.yml b/models/fixtures/action.yml
index e283b01db2..a75092feb0 100644
--- a/models/fixtures/action.yml
+++ b/models/fixtures/action.yml
@@ -56,3 +56,11 @@
   repo_id: 8 # public
   is_private: false
   created_unix: 1603011540 # grouped with id:7
+
+- id: 8
+  user_id: 1
+  op_type: 12 # close issue
+  act_user_id: 1
+  repo_id: 1700 # dangling intentional
+  is_private: false
+  created_unix: 1603011541
diff --git a/models/unittest/consistency.go b/models/unittest/consistency.go
index 2645084d3e..af05348868 100644
--- a/models/unittest/consistency.go
+++ b/models/unittest/consistency.go
@@ -175,8 +175,10 @@ func init() {
 
 	checkForActionConsistency := func(t assert.TestingT, bean interface{}) {
 		action := reflectionWrap(bean)
-		repoRow := AssertExistsAndLoadMap(t, "repository", builder.Eq{"id": action.int("RepoID")})
-		assert.Equal(t, parseBool(repoRow["is_private"]), action.bool("IsPrivate"), "action: %+v", action)
+		if action.int("RepoID") != 1700 { // dangling intentional
+			repoRow := AssertExistsAndLoadMap(t, "repository", builder.Eq{"id": action.int("RepoID")})
+			assert.Equal(t, parseBool(repoRow["is_private"]), action.bool("IsPrivate"), "action: %+v", action)
+		}
 	}
 
 	consistencyCheckMap["user"] = checkForUserConsistency