Fix address with Q-encoded display name containing double quotes

lib/mail/constants.rb

@@ -42,6 +42,7 @@ module Constants
     HYPHEN         = '-'
     COLON          = ':'
     ASTERISK       = '*'
+    DOUBLE_QUOTE   = '"'
     CR             = "\r"
     LF             = "\n"
     CR_ENCODED     = "=0D"

lib/mail/parsers/address_lists_parser.rb

@@ -86,15 +86,15 @@ def parse(s)
 
         # Don't set the display name until the
         # address has actually started. This allows
-        # us to choose quoted_s version if it
-        # exists and always use the 'full' phrase
+        # us to always use the 'full' phrase
         # version.
         when :angle_addr_s
-          if qstr
-            address.display_name = qstr
-            qstr = nil
-          elsif phrase_e
-            address.display_name = s[phrase_s..phrase_e].strip
+          if phrase_e
+            phrase = s[phrase_s..phrase_e].strip
+            if phrase[0, 1] == DOUBLE_QUOTE && phrase[-1, 1] == DOUBLE_QUOTE
+              phrase = phrase[1..-2]
+            end
+            address.display_name = phrase
             phrase_e = phrase_s = nil
           end
 
@@ -110,7 +110,7 @@ def parse(s)
         when :local_dot_atom_pre_comment_e
           local_dot_atom_pre_comment_e = p-1
         when :local_quoted_string_e
-          address.local = '"' + qstr + '"' if address
+          address.local = DOUBLE_QUOTE + qstr + DOUBLE_QUOTE if address
 
         # obs_domain_list
         when :obs_domain_list_s then obs_domain_list_s = p

lib/mail/utilities.rb

@@ -54,7 +54,7 @@ def quote_token( str )
     #  string = 'This is "a string"'
     #  dquote(string #=> '"This is \"a string\"'
     def dquote( str )
-      '"' + unquote(str).gsub(/[\\"]/n) {|s| '\\' + s } + '"'
+      DOUBLE_QUOTE + unquote(str).gsub(/[\\"]/n) {|s| '\\' + s } + DOUBLE_QUOTE
     end
 
     # Unwraps supplied string from inside double quotes and

spec/mail/elements/address_spec.rb

@@ -80,6 +80,26 @@
     it "should decode the display name without calling #decoded first" do
       encoded = '=?ISO-8859-1?Q?Jan_Kr=FCtisch?= <jan@krutisch.de>'
       expect(Mail::Address.new(encoded).display_name).to eq 'Jan Krütisch'
+
+      encoded = '=?ISO-8859-1?Q?Ja(n_Kr=FCt)isch?= <jan@krutisch.de>'
+      expect(Mail::Address.new(encoded).display_name).to eq 'Jaisch'
+      expect(Mail::Address.new(encoded).comments).to eq ['n_Kr=FCt']
+
+      encoded = '=?ISO-8859-1?Q?Jan_Kr=FCt(isc)h?= <jan@krutisch.de>'
+      expect(Mail::Address.new(encoded).display_name).to eq 'Jan Krüth'
+      expect(Mail::Address.new(encoded).comments).to eq ['isc']
+    end
+
+    it "should decode Q-encoded display name containing double quotes" do
+      encoded = '=?ISO-8859-1?Q?"Jan_Kr=FCtisch"?= <jan@krutisch.de>'
+      expect(Mail::Address.new(encoded).display_name).to eq '"Jan Krütisch"'
+
+      encoded = '=?ISO-8859-1?Q?Jan_Kr=FCti"s"ch?= <jan@krutisch.de>'
+      expect(Mail::Address.new(encoded).display_name).to eq 'Jan Krüti"s"ch'
+
+      encoded = '=?ISO-8859-1?Q?J(an)_Kr=FCti"s"ch?= <jan@krutisch.de>'
+      expect(Mail::Address.new(encoded).display_name).to eq 'J Krüti"s"ch'
+      expect(Mail::Address.new(encoded).comments).to eq ['an']
     end
 
     it "should give back the local part" do
@@ -669,7 +689,7 @@
       expect(address.encoded).to eq '=?UTF-8?B?44G+44GR44KL?= <mikel@test.lindsaar.net>'
     end
 
-    it "should provide an encoded output for non us-ascii" do
+    it "should provide a decoded output for non us-ascii" do
       address              = Mail::Address.new
       address.display_name = "まける"
       address.address      = "mikel@test.lindsaar.net"