Bug#907121: Fixed upstream

[Benjamin Moody]

Control: tags 907121 + patch

This issue appears to have been fixed upstream:
https://github.com/aptly-dev/aptly/commit/86dc10028f4f2a045797c9d3b072c7a034c257f7

Here's a slightly modified version of the above patch, which will fix
the issue for version 1.3.0:

--- aptly-1.3.0+ds1.orig/deb/format.go
+++ aptly-1.3.0+ds1/deb/format.go
@@ -4,6 +4,7 @@ import (
        "bufio"
        "errors"
        "io"
+       "sort"
        "strings"
        "unicode"
 )
@@ -166,8 +167,16 @@ func (s Stanza) WriteTo(w *bufio.Writer,
                }
        }

-       for field, value := range s {
-               err := writeField(w, field, value, isRelease)
+       // Print extra fields in deterministic order (alphabetical)
+       keys := make([]string, len(s))
+       i := 0
+       for field := range s {
+               keys[i] = field
+               i++
+       }
+       sort.Strings(keys)
+       for _, field := range keys {
+               err := writeField(w, field, s[field], isRelease)
                if err != nil {
                        return err
                }