threadbuilder: show siblings even when no parent found

Show all threading associations even when not all nodes are present.
Indicate if a thread is incomplete, i.e. misses a direct parent node.

Use the `msglist_thread_orphan.fg=red` styleobject in your stylesheet to
indicate whether a messsage has a missing parent.

Also use a different thread prefix ("┬─" instead of "├─") not to confuse
them with regular threads that have a visible parent.

Signed-off-by: Koni Marti <koni.marti@gmail.com>
Signed-off-by: Robin Jarry <robin@jarry.cc>
Tested-by: Matěj Cepl <mcepl@cepl.eu>

2 files changed, 33 insertions, 21 deletions

diff --git a/lib/state/templates.go b/lib/state/templates.go
index e5206cf0..868f9184 100644
--- a/lib/state/templates.go
+++ b/lib/state/templates.go
@@ -28,7 +28,7 @@ type DataSetter interface {
 	SetHeaders(*mail.Header, *models.OriginalMail)
 	SetInfo(*models.MessageInfo, int, bool)
 	SetVisual(bool)
-	SetThreading(string, bool, int, int, bool, bool)
+	SetThreading(ThreadInfo)
 	SetComposer(Composer)
 	SetAccount(*config.AccountConfig)
 	SetFolder(*models.Directory)
@@ -44,6 +44,7 @@ type ThreadInfo struct {
 	Unread      int
 	Folded      bool
 	Context     bool
+	Orphan      bool
 }
 
 type templateData struct {
@@ -100,15 +101,8 @@ func (d *templateData) SetVisual(visual bool) {
 	d.visual = visual
 }
 
-func (d *templateData) SetThreading(prefix string, same bool, count int,
-	unread int, folded bool, context bool,
-) {
-	d.threadInfo.Prefix = prefix
-	d.threadInfo.SameSubject = same
-	d.threadInfo.Count = count
-	d.threadInfo.Unread = unread
-	d.threadInfo.Folded = folded
-	d.threadInfo.Context = context
+func (d *templateData) SetThreading(info ThreadInfo) {
+	d.threadInfo = info
 }
 
 func (d *templateData) SetAccount(acct *config.AccountConfig) {
@@ -334,6 +328,10 @@ func (d *templateData) ThreadContext() bool {
 	return d.threadInfo.Context
 }
 
+func (d *templateData) ThreadOrphan() bool {
+	return d.threadInfo.Orphan
+}
+
 func (d *templateData) Subject() string {
 	var subject string
 	switch {
diff --git a/lib/threadbuilder.go b/lib/threadbuilder.go
index c18ab3d0..b7dae431 100644
--- a/lib/threadbuilder.go
+++ b/lib/threadbuilder.go
@@ -165,23 +165,30 @@ func (builder *ThreadBuilder) buildTree(c jwz.Threadable, parent *types.Thread,
 		return
 	}
 	for node := c; node != nil; node = node.GetNext() {
-		thread := parent
-		if !node.IsDummy() {
-			thread = builder.newThread(node, parent)
-			if rootLevel {
-				thread.NextSibling = parent.FirstChild
-				parent.FirstChild = thread
-			} else {
-				parent.InsertCmp(thread, bigger)
-			}
+		thread := builder.newThread(node, parent, node.IsDummy())
+		if rootLevel {
+			thread.NextSibling = parent.FirstChild
+			parent.FirstChild = thread
+		} else {
+			parent.InsertCmp(thread, bigger)
 		}
 		builder.buildTree(node.GetChild(), thread, bigger, node.IsDummy())
 	}
 }
 
-func (builder *ThreadBuilder) newThread(c jwz.Threadable, parent *types.Thread) *types.Thread {
+func (builder *ThreadBuilder) newThread(c jwz.Threadable, parent *types.Thread,
+	hidden bool,
+) *types.Thread {
+	hide := 0
+	if hidden {
+		hide += 1
+	}
 	if threadable, ok := c.(*threadable); ok {
-		return &types.Thread{Uid: threadable.MsgInfo.Uid, Parent: parent}
+		return &types.Thread{
+			Uid:    threadable.UID(),
+			Parent: parent,
+			Hidden: hide,
+		}
 	}
 	return nil
 }
@@ -297,6 +304,13 @@ func cleanRefs(m, irp string, refs []string) []string {
 	return cleanRefs
 }
 
+func (t *threadable) UID() uint32 {
+	if t.MsgInfo == nil {
+		return 0
+	}
+	return t.MsgInfo.Uid
+}
+
 func (t *threadable) Subject() string {
 	// deactivate threading by subject for now
 	return ""