From 8d10e053d4f424a87fb63627366ed1bbe5bc7e51 Mon Sep 17 00:00:00 2001
From: kolaente
Date: Sun, 28 Jun 2026 00:01:07 +0200
Subject: [PATCH] fix(caldav): store markdown descriptions as HTML, skip
spurious updates
Incoming CalDAV descriptions are markdown; convert them back to canonical HTML
(rebuilding mentions) before persisting. Skip the conversion when the markdown
is unchanged from the stored HTML so a passthrough sync doesn't churn the value
or bump the ETag.
---
pkg/routes/caldav/description_test.go | 88 ++++++++++++++++++++++++
pkg/routes/caldav/listStorageProvider.go | 34 +++++++++
2 files changed, 122 insertions(+)
create mode 100644 pkg/routes/caldav/description_test.go
diff --git a/pkg/routes/caldav/description_test.go b/pkg/routes/caldav/description_test.go
new file mode 100644
index 000000000..f70288d35
--- /dev/null
+++ b/pkg/routes/caldav/description_test.go
@@ -0,0 +1,88 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see .
+
+package caldav
+
+import (
+ "testing"
+
+ "code.vikunja.io/api/pkg/db"
+ "code.vikunja.io/api/pkg/models"
+
+ "github.com/stretchr/testify/assert"
+ "github.com/stretchr/testify/require"
+)
+
+func TestApplyDescriptionFromMarkdown(t *testing.T) {
+ t.Run("unchanged round trip keeps stored html verbatim", func(t *testing.T) {
+ db.LoadAndAssertFixtures(t)
+ s := db.NewSession()
+ defer s.Close()
+
+ const stored = `Hello world
`
+ vTask := &models.Task{Description: "Hello **world**"}
+
+ require.NoError(t, applyDescriptionFromMarkdown(s, vTask, stored))
+ assert.Equal(t, stored, vTask.Description)
+ })
+
+ t.Run("edited markdown is converted to html", func(t *testing.T) {
+ db.LoadAndAssertFixtures(t)
+ s := db.NewSession()
+ defer s.Close()
+
+ const stored = `Hello world
`
+ vTask := &models.Task{Description: "Hello **mars**"}
+
+ require.NoError(t, applyDescriptionFromMarkdown(s, vTask, stored))
+ assert.Equal(t, "Hello mars
", vTask.Description)
+ })
+
+ t.Run("mention is rebuilt from markdown", func(t *testing.T) {
+ db.LoadAndAssertFixtures(t)
+ s := db.NewSession()
+ defer s.Close()
+
+ vTask := &models.Task{Description: "ping @user1"}
+
+ require.NoError(t, applyDescriptionFromMarkdown(s, vTask, ""))
+ assert.Contains(t, vTask.Description, `done
")
+ })
+
+ t.Run("emptying a description is honoured", func(t *testing.T) {
+ db.LoadAndAssertFixtures(t)
+ s := db.NewSession()
+ defer s.Close()
+
+ vTask := &models.Task{Description: ""}
+
+ require.NoError(t, applyDescriptionFromMarkdown(s, vTask, "was here
"))
+ assert.Empty(t, vTask.Description)
+ })
+}
diff --git a/pkg/routes/caldav/listStorageProvider.go b/pkg/routes/caldav/listStorageProvider.go
index 60a151e2d..e59761328 100644
--- a/pkg/routes/caldav/listStorageProvider.go
+++ b/pkg/routes/caldav/listStorageProvider.go
@@ -28,6 +28,7 @@ import (
"code.vikunja.io/api/pkg/events"
"code.vikunja.io/api/pkg/log"
"code.vikunja.io/api/pkg/models"
+ "code.vikunja.io/api/pkg/richtext"
user2 "code.vikunja.io/api/pkg/user"
"code.vikunja.io/api/pkg/web"
"github.com/samedi/caldav-go/data"
@@ -364,6 +365,14 @@ func (vcls *VikunjaCaldavProjectStorage) CreateResource(rpath, content string) (
return nil, errs.ForbiddenError
}
+ // Inbound CalDAV descriptions are markdown; store them as canonical HTML.
+ if err := applyDescriptionFromMarkdown(s, vTask, ""); err != nil {
+ log.Errorf("[CALDAV] Failed to convert description in CreateResource: %v", err)
+ _ = s.Rollback()
+ events.CleanupPending(s)
+ return nil, err
+ }
+
// Create the task
err = vTask.Create(s, vcls.user)
if err != nil {
@@ -408,6 +417,23 @@ func (vcls *VikunjaCaldavProjectStorage) CreateResource(rpath, content string) (
return &r, nil
}
+// applyDescriptionFromMarkdown converts a task's inbound CalDAV description
+// (markdown) to canonical HTML, rebuilding @mentions. Unchanged markdown keeps the
+// stored HTML verbatim, so a no-op read-modify-write doesn't churn it or move Updated.
+func applyDescriptionFromMarkdown(s *xorm.Session, vTask *models.Task, storedHTML string) error {
+ if !richtext.Changed(storedHTML, vTask.Description) {
+ vTask.Description = storedHTML
+ return nil
+ }
+
+ htmlDesc, err := richtext.MarkdownToHTMLWithMentions(s, vTask.Description)
+ if err != nil {
+ return err
+ }
+ vTask.Description = htmlDesc
+ return nil
+}
+
// UpdateResource updates a resource
func (vcls *VikunjaCaldavProjectStorage) UpdateResource(rpath, content string) (*data.Resource, error) {
@@ -443,6 +469,14 @@ func (vcls *VikunjaCaldavProjectStorage) UpdateResource(rpath, content string) (
return nil, errs.ForbiddenError
}
+ // Inbound markdown → canonical HTML, kept verbatim when unchanged.
+ if err := applyDescriptionFromMarkdown(s, vTask, vcls.task.Description); err != nil {
+ log.Errorf("[CALDAV] Failed to convert description in UpdateResource: %v", err)
+ _ = s.Rollback()
+ events.CleanupPending(s)
+ return nil, err
+ }
+
// Update the task
err = vTask.Update(s, vcls.user)
if err != nil {