pgp: fix pipe|open|save command behavior

Signed and/or encrypted PGP messages did not behave properly for pipe,
open, and save commands. Specifically, the proper Message Part would not
be passed to the command in the MessageViewer. This is due to the
encapsulation of the body structure. This patch fixes the behavior for
piping|opening|saving of message parts.

Fixes: https://todo.sr.ht/~rjarry/aerc/47
Reported-by: ~ph14nix
Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
Tested-by: Moritz Poldrack <moritz@poldrack.dev>
Acked-by: Robin Jarry <robin@jarry.cc>

commands/msg/pipe.go

@@ -182,12 +182,15 @@ func (Pipe) Execute(aerc *widgets.Aerc, args []string) error {
 			}
 		}()
 	} else if pipePart {
+		mv, ok := provider.(*widgets.MessageViewer)
+		if !ok {
+			return fmt.Errorf("can only pipe message part from a message view")
+		}
 		p := provider.SelectedMessagePart()
 		if p == nil {
 			return fmt.Errorf("could not fetch message part")
 		}
-		store := provider.Store()
-		store.FetchBodyPart(p.Msg.Uid, p.Index, func(reader io.Reader) {
+		mv.MessageView().FetchBodyPart(p.Index, func(reader io.Reader) {
 			if background {
 				doExec(reader)
 			} else {

commands/msgview/open.go

@@ -49,8 +49,7 @@ func (Open) Execute(aerc *widgets.Aerc, args []string) error {
 		return nil
 	}
 
-	store := mv.Store()
-	store.FetchBodyPart(p.Msg.Uid, p.Index, func(reader io.Reader) {
+	mv.MessageView().FetchBodyPart(p.Index, func(reader io.Reader) {
 		extension := ""
 		// try to determine the correct extension based on mimetype
 		if part, err := p.Msg.BodyStructure.PartAtIndex(p.Index); err == nil {

commands/msgview/save.go

@@ -13,7 +13,6 @@ import (
 	"github.com/mitchellh/go-homedir"
 
 	"git.sr.ht/~rjarry/aerc/commands"
-	"git.sr.ht/~rjarry/aerc/lib"
 	"git.sr.ht/~rjarry/aerc/logging"
 	"git.sr.ht/~rjarry/aerc/models"
 	"git.sr.ht/~rjarry/aerc/widgets"
@@ -105,8 +104,6 @@ func (Save) Execute(aerc *widgets.Aerc, args []string) error {
 		return fmt.Errorf("SelectedTab is not a MessageViewer")
 	}
 
-	store := mv.Store()
-
 	if params.attachments {
 		parts := mv.AttachmentParts()
 		if len(parts) == 0 {
@@ -114,7 +111,7 @@ func (Save) Execute(aerc *widgets.Aerc, args []string) error {
 		}
 		params.trailingSlash = true
 		for _, pi := range parts {
-			if err := savePart(pi, path, store, aerc, &params); err != nil {
+			if err := savePart(pi, path, mv, aerc, &params); err != nil {
 				return err
 			}
 		}
@@ -122,13 +119,13 @@ func (Save) Execute(aerc *widgets.Aerc, args []string) error {
 	}
 
 	pi := mv.SelectedMessagePart()
-	return savePart(pi, path, store, aerc, &params)
+	return savePart(pi, path, mv, aerc, &params)
 }
 
 func savePart(
 	pi *widgets.PartInfo,
 	path string,
-	store *lib.MessageStore,
+	mv *widgets.MessageViewer,
 	aerc *widgets.Aerc,
 	params *saveParams,
 ) error {
@@ -151,7 +148,7 @@ func savePart(
 	}
 
 	ch := make(chan error, 1)
-	store.FetchBodyPart(pi.Msg.Uid, pi.Index, func(reader io.Reader) {
+	mv.MessageView().FetchBodyPart(pi.Index, func(reader io.Reader) {
 		f, err := os.Create(path)
 		if err != nil {
 			ch <- err

widgets/msgviewer.go

@@ -290,6 +290,10 @@ func (mv *MessageViewer) SelectedAccount() *AccountView {
 	return mv.acct
 }
 
+func (mv *MessageViewer) MessageView() lib.MessageView {
+	return mv.msg
+}
+
 func (mv *MessageViewer) SelectedMessage() (*models.MessageInfo, error) {
 	if mv.msg == nil {
 		return nil, errors.New("no message selected")