Update Go doc comments to Go 1.19's format

This patch is the result of running Go 1.19's `gofmt` on the codebase,
which automatically updates all Go doc comments to the new format.

https://tip.golang.org/doc/go1.19#go-doc

internal/aliases/aliases.go

@@ -3,16 +3,15 @@
 // The resolver can parse many files for different domains, and perform
 // lookups to resolve the aliases.
 //
-//
-// File format
+// # File format
 //
 // It generally follows the traditional aliases format used by sendmail and
 // exim.
 //
 // The file can contain lines of the form:
 //
-//   user: address, address
-//   user: | command
+//	user: address, address
+//	user: | command
 //
 // Lines starting with "#" are ignored, as well as empty lines.
 // User names cannot contain spaces, ":" or commas, for parsing reasons. This
@@ -27,18 +26,16 @@
 // If the user is the string "*", then it is considered a "catch-all alias":
 // emails that don't match any known users or other aliases will be sent here.
 //
-//
-// Recipients
+// # Recipients
 //
 // Recipients can be of different types:
-//  - Email: the usual user@domain we all know and love, this is the default.
-//  - Pipe: if the right side starts with "| ", the rest of the line specifies
-//      a command to pipe the email through.
-//      Command and arguments are space separated. No quoting, escaping, or
-//      replacements of any kind.
+//   - Email: the usual user@domain we all know and love, this is the default.
+//   - Pipe: if the right side starts with "| ", the rest of the line specifies
+//     a command to pipe the email through.
+//     Command and arguments are space separated. No quoting, escaping, or
+//     replacements of any kind.
 //
-//
-// Lookups
+// # Lookups
 //
 // The resolver will perform lookups recursively, until it finds all the final
 // recipients.
@@ -46,8 +43,7 @@
 // There are recursion limits to avoid alias loops. If the limit is reached,
 // the entire resolution will fail.
 //
-//
-// Suffix removal
+// # Suffix removal
 //
 // The resolver can also remove suffixes from emails, and drop characters
 // completely. This can be used to turn "user+blah@domain" into "user@domain",

internal/auth/auth.go

@@ -162,7 +162,8 @@ func (a *Authenticator) Reload() error {
 // DecodeResponse decodes a plain auth response.
 //
 // It must be a a base64-encoded string of the form:
-//   <authorization id> NUL <authentication id> NUL <password>
+//
+//	<authorization id> NUL <authentication id> NUL <password>
 //
 // https://tools.ietf.org/html/rfc4954#section-4.1.
 //

internal/courier/mda.go

@@ -20,8 +20,8 @@ var (
 
 // MDA delivers local mail by executing a local binary, like procmail or
 // maildrop.  It works with any binary that:
-//  - Receives the email to deliver via stdin.
-//  - Exits with code EX_TEMPFAIL (75) for transient issues.
+//   - Receives the email to deliver via stdin.
+//   - Exits with code EX_TEMPFAIL (75) for transient issues.
 type MDA struct {
 	Binary  string        // Path to the binary.
 	Args    []string      // Arguments to pass.

internal/smtp/smtp.go

@@ -1,9 +1,8 @@
 // Package smtp implements the Simple Mail Transfer Protocol as defined in RFC
 // 5321.  It extends net/smtp as follows:
 //
-//  - Supports SMTPUTF8, via MailAndRcpt.
-//  - Adds IsPermanent.
-//
+//   - Supports SMTPUTF8, via MailAndRcpt.
+//   - Adds IsPermanent.
 package smtp
 
 import (
@@ -87,11 +86,11 @@ func (c *Client) MailAndRcpt(from string, to string) error {
 
 // prepareForSMTPUTF8 prepares the address for SMTPUTF8.
 // It returns:
-//  - The address to use. It is based on addr, and possibly modified to make
-//    it not need the extension, if the server does not support it.
-//  - Whether the address needs the extension or not.
-//  - An error if the address needs the extension, but the client does not
-//    support it.
+//   - The address to use. It is based on addr, and possibly modified to make
+//     it not need the extension, if the server does not support it.
+//   - Whether the address needs the extension or not.
+//   - An error if the address needs the extension, but the client does not
+//     support it.
 func (c *Client) prepareForSMTPUTF8(addr string) (string, bool, error) {
 	// ASCII address pass through.
 	if isASCII(addr) {

internal/sts/sts.go

@@ -3,7 +3,6 @@
 // Note that "report" mode is not supported.
 //
 // Reference: https://tools.ietf.org/html/rfc8461
-//
 package sts
 
 import (

internal/userdb/userdb.go

@@ -1,7 +1,6 @@
 // Package userdb implements a simple user database.
 //
-//
-// Format
+// # Format
 //
 // The user database is a file containing a list of users and their passwords,
 // encrypted with some scheme.
@@ -13,21 +12,18 @@
 // Users must be UTF-8 and NOT contain whitespace; the library will enforce
 // this.
 //
-//
-// Schemes
+// # Schemes
 //
 // The default scheme is SCRYPT, with hard-coded parameters. The API does not
 // allow the user to change this, at least for now.
 // A PLAIN scheme is also supported for debugging purposes.
 //
-//
-// Writing
+// # Writing
 //
 // The functions that write a database file will not preserve ordering,
 // invalid lines, empty lines, or any formatting.
 //
 // It is also not safe for concurrent use from different processes.
-//
 package userdb
 
 //go:generate protoc --go_out=. --go_opt=paths=source_relative userdb.proto

test/util/minidns/minidns.go

@@ -5,18 +5,17 @@
 //
 // It takes an "answers" file which contains lines with the following format:
 //
-//   <domain> <type> <value>
+//	<domain> <type> <value>
 //
 // For example:
 //
-//   blah A  1.2.3.4
-//   blah MX mx1
+//	blah A  1.2.3.4
+//	blah MX mx1
 //
 // Supported types: A, AAAA, MX, TXT.
 //
 // It's only meant to be used for testing, so it's not robust, performant, or
 // standards compliant.
-//
 package main
 
 import (