jmap: explicitly fetch body structure subparts

When requesting the bodyStructure email property, the spec says that the
default returned body part properties are: ["partId", "blobId", "size",
"name", "type", "charset", "disposition", "cid", "language",
"location"].

Specifically, the "subParts" property is *NOT* expected by default.

Fastmail servers seem to use a different default "bodyProperties" list
and implicitly return "subParts" even if not requested.

Other JMAP server implementations (e.g. Apache James) do use the RFC
default "bodyProperties" and therefore omit returning "subParts" unless
explicitly asked to.

Change the requested "bodyProperties" to include "subParts" as well.
Aerc needs them to display messages.

NB: for later, we should probably change our message abstraction not to
include any body structure. This makes very little sense to expose that
to users. In fact, aerc has code to explicitly prevent users from
selecting multipart/* parts. Not requesting that information to the
server would make it easier.

Link: https://datatracker.ietf.org/doc/html/rfc8621#section-4.2
Reported-by: Benoit Tellier <[email protected]>
Signed-off-by: Robin Jarry <[email protected]>
Reviewed-by: Tim Culverhouse <[email protected]>

worker/jmap/fetch.go

@@ -13,7 +13,21 @@ import (
 	"github.com/emersion/go-message/charset"
 )
 
-var headersProperties = []string{
+var bodyProperties = []string{
+	"blobId",
+	"charset",
+	"cid",
+	"disposition",
+	"language",
+	"location",
+	"name",
+	"partId",
+	"size",
+	"subParts",
+	"type",
+}
+
+var emailProperties = []string{
 	"id",
 	"blobId",
 	"threadId",
@@ -57,9 +71,10 @@ func (w *JMAPWorker) handleFetchMessageHeaders(msg *types.FetchMessageHeaders) e
 		var req jmap.Request
 
 		req.Invoke(&email.Get{
-			Account:    w.AccountId(),
-			IDs:        emailIdsToFetch,
-			Properties: headersProperties,
+			Account:        w.AccountId(),
+			IDs:            emailIdsToFetch,
+			Properties:     emailProperties,
+			BodyProperties: bodyProperties,
 		})
 
 		resp, err := w.Do(&req)

worker/jmap/push.go

@@ -114,8 +114,9 @@ func (w *JMAPWorker) refresh(newState jmap.TypeState) error {
 			SinceState: emailState,
 		})
 		emailUpdated = req.Invoke(&email.Get{
-			Account:    w.AccountId(),
-			Properties: headersProperties,
+			Account:        w.AccountId(),
+			Properties:     emailProperties,
+			BodyProperties: bodyProperties,
 			ReferenceIDs: &jmap.ResultReference{
 				ResultOf: callID,
 				Name:     "Email/changes",
@@ -124,8 +125,9 @@ func (w *JMAPWorker) refresh(newState jmap.TypeState) error {
 		})
 
 		emailCreated = req.Invoke(&email.Get{
-			Account:    w.AccountId(),
-			Properties: headersProperties,
+			Account:        w.AccountId(),
+			Properties:     emailProperties,
+			BodyProperties: bodyProperties,
 			ReferenceIDs: &jmap.ResultReference{
 				ResultOf: callID,
 				Name:     "Email/changes",
@@ -378,9 +380,10 @@ func (w *JMAPWorker) refreshQueriesAndThreads(
 	}
 
 	req.Invoke(&email.Get{
-		Account:    w.AccountId(),
-		Properties: headersProperties,
-		IDs:        emailsToFetch,
+		Account:        w.AccountId(),
+		Properties:     emailProperties,
+		BodyProperties: bodyProperties,
+		IDs:            emailsToFetch,
 	})
 
 	resp, err := w.Do(&req)

worker/jmap/threads.go

@@ -29,7 +29,8 @@ func (w *JMAPWorker) fetchEntireThreads(threads []jmap.ID) ([]*email.Email, erro
 			Name:     "Thread/get",
 			Path:     "/list/*/emailIds",
 		},
-		Properties: headersProperties,
+		Properties:     emailProperties,
+		BodyProperties: bodyProperties,
 	})
 
 	resp, err := w.Do(&req)