normalize localparts with unicode nfc when parsing

both when parsing our configs, and for incoming on smtp or in messages.
so we properly compare things like é and e+accent as equal, and accept the
different encodings of that same address.

webmail/api.go

@@ -1347,7 +1347,7 @@ func (Webmail) CompleteRecipient(ctx context.Context, search string) ([]string,
 	acc.WithRLock(func() {
 		xdbread(ctx, acc, func(tx *bstore.Tx) {
 			type key struct {
-				localpart smtp.Localpart
+				localpart string
 				domain    string
 			}
 			seen := map[key]bool{}
@@ -1360,7 +1360,7 @@ func (Webmail) CompleteRecipient(ctx context.Context, search string) ([]string,
 					return nil
 				}
 				// todo: we should have the address including name available in the database for searching. Will result in better matching, and also for the name.
-				address := fmt.Sprintf("<%s@%s>", r.Localpart.String(), r.Domain)
+				address := fmt.Sprintf("<%s@%s>", r.Localpart, r.Domain)
 				if !strings.Contains(strings.ToLower(address), search) {
 					return nil
 				}
@@ -1382,7 +1382,7 @@ func (Webmail) CompleteRecipient(ctx context.Context, search string) ([]string,
 					xcheckf(ctx, err, "parsing domain of recipient")
 
 					var found bool
-					lp := r.Localpart.String()
+					lp := r.Localpart
 					checkAddrs := func(l []message.Address) {
 						if found {
 							return

webmail/api.json

@@ -1009,7 +1009,7 @@
 				},
 				{
 					"Name": "User",
-					"Docs": "Localpart.",
+					"Docs": "Localpart, encoded as string. Must be parsed before using as Localpart.",
 					"Typewords": [
 						"string"
 					]
@@ -1063,7 +1063,7 @@
 				},
 				{
 					"Name": "Unicode",
-					"Docs": "Name as U-labels. Empty if this is an ASCII-only domain. No trailing dot.",
+					"Docs": "Name as U-labels, in Unicode NFC. Empty if this is an ASCII-only domain. No trailing dot.",
 					"Typewords": [
 						"string"
 					]
@@ -2817,7 +2817,7 @@
 		},
 		{
 			"Name": "Localpart",
-			"Docs": "Localpart is a decoded local part of an email address, before the \"@\".\nFor quoted strings, values do not hold the double quote or escaping backslashes.\nAn empty string can be a valid localpart.",
+			"Docs": "Localpart is a decoded local part of an email address, before the \"@\".\nFor quoted strings, values do not hold the double quote or escaping backslashes.\nAn empty string can be a valid localpart.\nLocalparts are in Unicode NFC.",
 			"Values": null
 		}
 	],

webmail/api.ts

@@ -106,7 +106,7 @@ export interface Envelope {
 // Address as used in From and To headers.
 export interface Address {
 	Name: string  // Free-form name for display in mail applications.
-	User: string  // Localpart.
+	User: string  // Localpart, encoded as string. Must be parsed before using as Localpart.
 	Host: string  // Domain in ASCII.
 }
 
@@ -124,7 +124,7 @@ export interface MessageAddress {
 // trailing dot. When using with StrictResolver, add the trailing dot.
 export interface Domain {
 	ASCII: string  // A non-unicode domain, e.g. with A-labels (xn--...) or NR-LDH (non-reserved letters/digits/hyphens) labels. Always in lower case. No trailing dot.
-	Unicode: string  // Name as U-labels. Empty if this is an ASCII-only domain. No trailing dot.
+	Unicode: string  // Name as U-labels, in Unicode NFC. Empty if this is an ASCII-only domain. No trailing dot.
 }
 
 // SubmitMessage is an email message to be sent to one or more recipients.
@@ -516,6 +516,7 @@ export enum SecurityResult {
 // Localpart is a decoded local part of an email address, before the "@".
 // For quoted strings, values do not hold the double quote or escaping backslashes.
 // An empty string can be a valid localpart.
+// Localparts are in Unicode NFC.
 export type Localpart = string
 
 export const structTypes: {[typename: string]: boolean} = {"Address":true,"Attachment":true,"ChangeMailboxAdd":true,"ChangeMailboxCounts":true,"ChangeMailboxKeywords":true,"ChangeMailboxRemove":true,"ChangeMailboxRename":true,"ChangeMailboxSpecialUse":true,"ChangeMsgAdd":true,"ChangeMsgFlags":true,"ChangeMsgRemove":true,"ChangeMsgThread":true,"Domain":true,"DomainAddressConfig":true,"Envelope":true,"EventStart":true,"EventViewChanges":true,"EventViewErr":true,"EventViewMsgs":true,"EventViewReset":true,"File":true,"Filter":true,"Flags":true,"ForwardAttachments":true,"Mailbox":true,"Message":true,"MessageAddress":true,"MessageEnvelope":true,"MessageItem":true,"NotFilter":true,"Page":true,"ParsedMessage":true,"Part":true,"Query":true,"RecipientSecurity":true,"Request":true,"SpecialUse":true,"SubmitMessage":true}