[geary] Geary.RFC822.MailboxAddress: Handle long headers being folded

[Michael Gratton <mjog src gnome org>]

commit 3c4d5c5e9d1444cce1e2027091c4558262ef1a70
Author: Michael Gratton <mike vee net>
Date:   Wed Jan 20 19:22:46 2021 +1100

    Geary.RFC822.MailboxAddress: Handle long headers being folded
    
    Remove "\n " sequences from RFC822 text before decoding so that any
    long mailboxes/mailbox lists folded before the 80 char limit are
    unfolded.
    
    Fixes #1009

 src/engine/rfc822/rfc822-mailbox-address.vala       |  6 +++---
 test/engine/rfc822/rfc822-mailbox-address-test.vala | 21 +++++++++++++++------
 2 files changed, 18 insertions(+), 9 deletions(-)
---
diff --git a/src/engine/rfc822/rfc822-mailbox-address.vala b/src/engine/rfc822/rfc822-mailbox-address.vala
index 1e23fca47..90a337a2c 100644
--- a/src/engine/rfc822/rfc822-mailbox-address.vala
+++ b/src/engine/rfc822/rfc822-mailbox-address.vala
@@ -136,11 +136,11 @@ public class Geary.RFC822.MailboxAddress :
             : GMime.utils_decode_8bit(get_parser_options(), part.data)
         );
 
-        // unquote the string then decode the text
+        text = GMime.utils_header_unfold(text);
         GMime.utils_unquote_string(text);
 
-        // Sometimes quoted printables contain unencoded spaces which trips up GMime, so we want to
-        // encode them all here.
+        // Sometimes quoted printables contain unencoded spaces which
+        // trips up GMime, so we want to encode them all here.
         int offset = 0;
         int start;
         while ((start = text.index_of("=?", offset)) != -1) {
diff --git a/test/engine/rfc822/rfc822-mailbox-address-test.vala 
b/test/engine/rfc822/rfc822-mailbox-address-test.vala
index fdef5b0b7..a79a1a861 100644
--- a/test/engine/rfc822/rfc822-mailbox-address-test.vala
+++ b/test/engine/rfc822/rfc822-mailbox-address-test.vala
@@ -234,12 +234,21 @@ class Geary.RFC822.MailboxAddressTest : TestCase {
         assert(new MailboxAddress("test", "example@example example com").is_spoofed() == true);
         assert(new MailboxAddress("'prefix-example example com'", "example example com").is_spoofed() == 
true);
 
-        try {
-            assert(new 
MailboxAddress.from_rfc822_string("\"=?utf-8?b?dGVzdCIgPHBvdHVzQHdoaXRlaG91c2UuZ292Pg==?==?utf-8?Q?=00=0A?=\" 
<demo mailsploit com>")
-                   .is_spoofed() == true);
-        } catch (Error err) {
-            assert_no_error(err);
-        }
+        assert_false(
+            new MailboxAddress.from_rfc822_string(
+                "hello\n there <example example com>"
+            ).is_spoofed()
+        );
+        assert_false(
+            new MailboxAddress.from_rfc822_string(
+                "\"hello\n there\" <example example com>"
+            ).is_spoofed()
+        );
+        assert_true(
+            new MailboxAddress.from_rfc822_string(
+                "\"=?utf-8?b?dGVzdCIgPHBvdHVzQHdoaXRlaG91c2UuZ292Pg==?==?utf-8?Q?=00=0A?=\" <demo mailsploit 
com>"
+            ).is_spoofed()
+        );
     }
 
     public void to_full_display() throws GLib.Error {