lib: prepare attachments for multiple reads

Prepare attachments for multiple reads. The data for lib.PartAttachment
is stored as an io.Reader which can only be read once. This will cause
an issue when we want to call composer.WriteMessage multiple times, i.e.
for a message preview. We fix this by keeping a copy of the data and
create a new reader everytime the attachment is read.

Signed-off-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>

1 files changed, 5 insertions, 1 deletions

diff --git a/commands/msg/forward.go b/commands/msg/forward.go
index 78c24380..ccfaa086 100644
--- a/commands/msg/forward.go
+++ b/commands/msg/forward.go
@@ -205,8 +205,12 @@ func (forward) Execute(aerc *widgets.Aerc, args []string) error {
 							name = fmt.Sprintf("%s_%s_%d", bs.MIMEType, bs.MIMESubType, rand.Uint64())
 						}
 						mu.Lock()
-						composer.AddPartAttachment(name, mime, params, reader)
+						err := composer.AddPartAttachment(name, mime, params, reader)
 						mu.Unlock()
+						if err != nil {
+							logging.Errorf(err.Error())
+							aerc.PushError(err.Error())
+						}
 					})
 				}
 			}