[geary/wip/491-email-spoofing-case] Fix "'test example com' <test example com>" marked as spoofed

[Michael Gratton <mjog src gnome org>]

commit bed1bad3ea0250d6d3998fcee8204f66bc4b7636
Author: Michael Gratton <mike vee net>
Date:   Sat Jul 6 14:38:05 2019 +1000

    Fix "'test example com' <test example com>" marked as spoofed
    
    Make RFC833.MailboxAddress.has_distinct_name() consider substrings
    rather than straight-up string comparison.
    
    See #491

 src/engine/rfc822/rfc822-mailbox-address.vala | 18 ++++++++++--------
 test/engine/rfc822-mailbox-address-test.vala  | 26 +++++++++++++++-----------
 2 files changed, 25 insertions(+), 19 deletions(-)
---
diff --git a/src/engine/rfc822/rfc822-mailbox-address.vala b/src/engine/rfc822/rfc822-mailbox-address.vala
index 448c6c9c..07560000 100644
--- a/src/engine/rfc822/rfc822-mailbox-address.vala
+++ b/src/engine/rfc822/rfc822-mailbox-address.vala
@@ -409,17 +409,19 @@ public class Geary.RFC822.MailboxAddress :
      * Determines if the name part is different to the address part.
      *
      * @return //true// if {@link name} is not empty, and the
-     * normalised name part and {@link address} are not equal when
-     * performing a case-insensitive comparison.
+     * normalised {@link address} part is not contained within the
+     * name part when performing a case-insensitive comparison.
      */
     public bool has_distinct_name() {
         string name = Geary.String.reduce_whitespace(this.name);
-        return (
-            !Geary.String.is_empty(name) &&
-            name.normalize().casefold() != Geary.String.reduce_whitespace(
-                this.address.normalize().casefold()
-            )
-        );
+        bool ret = false;
+        if (!Geary.String.is_empty(name)) {
+            string address = Geary.String.reduce_whitespace(
+                this.address.normalize()
+            );
+            ret = !(address.normalize().casefold() in name.casefold());
+        }
+        return ret;
     }
 
     /**
diff --git a/test/engine/rfc822-mailbox-address-test.vala b/test/engine/rfc822-mailbox-address-test.vala
index b6e30789..ceb32381 100644
--- a/test/engine/rfc822-mailbox-address-test.vala
+++ b/test/engine/rfc822-mailbox-address-test.vala
@@ -12,8 +12,9 @@ class Geary.RFC822.MailboxAddressTest : TestCase {
         add_test("is_valid_address", is_valid_address);
         add_test("unescaped_constructor", unescaped_constructor);
         add_test("from_rfc822_string_encoded", from_rfc822_string_encoded);
-        add_test("is_spoofed", is_spoofed);
+        // latter depends on the former, so test that first
         add_test("has_distinct_name", has_distinct_name);
+        add_test("is_spoofed", is_spoofed);
         add_test("to_full_display", to_full_display);
         add_test("to_short_display", to_short_display);
         // latter depends on the former, so test that first
@@ -151,6 +152,17 @@ class Geary.RFC822.MailboxAddressTest : TestCase {
         }
     }
 
+    public void has_distinct_name() throws Error {
+        assert(new MailboxAddress("example", "example example com").has_distinct_name() == true);
+
+        assert(new MailboxAddress("", "example example com").has_distinct_name() == false);
+        assert(new MailboxAddress(" ", "example example com").has_distinct_name() == false);
+        assert(new MailboxAddress("example example com", "example example com").has_distinct_name() == 
false);
+        assert(new MailboxAddress(" example example com ", "example example com").has_distinct_name() == 
false);
+        assert(new MailboxAddress(" example example com ", "example example com").has_distinct_name() == 
false);
+        assert(new MailboxAddress("'example example com'", "example example com").has_distinct_name() == 
false);
+    }
+
     public void is_spoofed() throws Error {
         assert(new MailboxAddress(null, "example example com").is_spoofed() == false);
         assert(new MailboxAddress("", "example example com").is_spoofed() == false);
@@ -161,6 +173,7 @@ class Geary.RFC822.MailboxAddressTest : TestCase {
         assert(new MailboxAddress("test?", "example example com").is_spoofed() == false);
         assert(new MailboxAddress("test example com", "test example com").is_spoofed() == false);
         assert(new MailboxAddress("test EXAMPLE com", "test example com").is_spoofed() == false);
+        assert(new MailboxAddress("'example example com'", "example example com").is_spoofed() == false);
 
         assert(new MailboxAddress("test example com", "example example com").is_spoofed() == true);
         assert(new MailboxAddress("test @ example . com", "example example com").is_spoofed() == true);
@@ -169,6 +182,7 @@ class Geary.RFC822.MailboxAddressTest : TestCase {
         assert(new MailboxAddress("test", "example@\nexample example com").is_spoofed() == true);
         assert(new MailboxAddress("test", "example@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);
@@ -177,16 +191,6 @@ class Geary.RFC822.MailboxAddressTest : TestCase {
         }
     }
 
-    public void has_distinct_name() throws Error {
-        assert(new MailboxAddress("example", "example example com").has_distinct_name() == true);
-
-        assert(new MailboxAddress("", "example example com").has_distinct_name() == false);
-        assert(new MailboxAddress(" ", "example example com").has_distinct_name() == false);
-        assert(new MailboxAddress("example example com", "example example com").has_distinct_name() == 
false);
-        assert(new MailboxAddress(" example example com ", "example example com").has_distinct_name() == 
false);
-        assert(new MailboxAddress(" example example com ", "example example com").has_distinct_name() == 
false);
-    }
-
     public void to_full_display() throws Error {
         assert(new MailboxAddress("", "example example com").to_full_display() ==
                "example example com");