Allow to send calendar update multiple times

Changelog.md

@@ -11,6 +11,8 @@ Changelog [format](http://keepachangelog.com/en/1.0.0/)
 * Bump crypto version to v0.0.0-20200818122824-ed5d25e28db8
 * GODT-785 Clear separation of different message IDs in integration tests.
 
+* Bump crypto version to v0.0.0-20200818122824-ed5d25e28db8.
+* GODT-374 Allow to send calendar update multiple times.
 
 ## [IE 1.1.1] Danube (beta 2020-09-xx) [Bridge 1.4.1] Forth (beta 2020-09-xx)
 

internal/smtp/send_recorder.go

@@ -20,6 +20,7 @@ package smtp
 import (
 	"crypto/sha256"
 	"fmt"
+	"strings"
 	"sync"
 	"time"
 
@@ -48,6 +49,15 @@ func newSendRecorder() *sendRecorder {
 }
 
 func (q *sendRecorder) getMessageHash(message *pmapi.Message) string {
+	// Outlook Calendar updates has only headers (no body) and thus have always
+	// the same hash. If the message is type of calendar, the "is sending"
+	// check to avoid potential duplicates is skipped. Duplicates should not
+	// be a problem in this case as calendar updates are small.
+	contentType := message.Header.Get("Content-Type")
+	if strings.HasPrefix(contentType, "text/calendar") {
+		return ""
+	}
+
 	h := sha256.New()
 	_, _ = h.Write([]byte(message.AddressID + message.Subject))
 	if message.Sender != nil {
@@ -101,6 +111,10 @@ func (q *sendRecorder) isSendingOrSent(client messageGetter, hash string) (isSen
 	q.lock.Lock()
 	defer q.lock.Unlock()
 
+	if hash == "" {
+		return false, false
+	}
+
 	q.deleteExpiredKeys()
 	value, ok := q.hashes[hash]
 	if !ok {

internal/smtp/send_recorder_test.go

@@ -349,6 +349,32 @@ func TestSendRecorder_getMessageHash(t *testing.T) {
 			},
 			false,
 		},
+		{ // Different content type - calendar
+			&pmapi.Message{
+				Header: mail.Header{
+					"Content-Type": []string{"text/calendar"},
+				},
+				AddressID: "address123",
+				Subject:   "Subject #1",
+				Sender: &mail.Address{
+					Address: "from@pm.me",
+				},
+				ToList: []*mail.Address{
+					{Address: "to@pm.me"},
+				},
+				CCList:  []*mail.Address{},
+				BCCList: []*mail.Address{},
+				Body:    "body",
+				Attachments: []*pmapi.Attachment{
+					{
+						Name:     "att1",
+						MIMEType: "image/png",
+						Size:     12345,
+					},
+				},
+			},
+			false,
+		},
 	}
 	for i, tc := range testCases {
 		tc := tc // bind
@@ -382,12 +408,13 @@ func TestSendRecorder_isSendingOrSent(t *testing.T) {
 		{"hash", &pmapi.Message{Type: pmapi.MessageTypeDraft, Time: time.Now().Unix()}, nil, true, false},
 		{"hash", &pmapi.Message{Type: pmapi.MessageTypeSent}, nil, false, true},
 		{"hash", &pmapi.Message{Type: pmapi.MessageTypeInboxAndSent}, nil, false, true},
+		{"", &pmapi.Message{Type: pmapi.MessageTypeInboxAndSent}, nil, false, false},
 	}
 	for i, tc := range testCases {
 		tc := tc // bind
 		t.Run(fmt.Sprintf("%d / %v / %v / %v", i, tc.hash, tc.message, tc.err), func(t *testing.T) {
 			messageGetter := &testSendRecorderGetMessageMock{message: tc.message, err: tc.err}
-			isSending, wasSent := q.isSendingOrSent(messageGetter, "hash")
+			isSending, wasSent := q.isSendingOrSent(messageGetter, tc.hash)
 			assert.Equal(t, tc.wantIsSending, isSending, "isSending does not match")
 			assert.Equal(t, tc.wantWasSent, wasSent, "wasSent does not match")
 		})