avoid auto_linking already linked emails; more robust detection of li…

…nked URLs

References #1523  [#1862 state:resolved]  [#3591 state:resolved]

Add test that shows how link text can contain HTML if needed:
the trick is using block form in combination with `raw`.
Let link text be automatically HTML-escaped

[#2017 state:resolved]

actionpack/lib/action_view/helpers/text_helper.rb

@@ -534,7 +534,12 @@ def set_cycle(name, cycle_object)
         AUTO_LINK_RE = %r{
             (?: ([\w+.:-]+:)// | www\. )
             [^\s<]+
-          }x unless const_defined?(:AUTO_LINK_RE)
+          }x
+
+        # regexps for determining context, used high-volume
+        AUTO_LINK_CRE = [/<[^>]+$/, /^[^>]*>/, /<a\b.*?>/i, /<\/a>/i]
+
+        AUTO_EMAIL_RE = /[\w.!#\$%+-]+@[\w-]+(?:\.[\w-]+)+/
 
         BRACKETS = { ']' => '[', ')' => '(', '}' => '{' }
 
@@ -545,9 +550,8 @@ def auto_link_urls(text, html_options = {})
           text.gsub(AUTO_LINK_RE) do
             scheme, href = $1, $&
             punctuation = ''
-            left, right = $`, $'
-            # detect already linked URLs and URLs in the middle of a tag
-            if left =~ /<[^>]+$/ && right =~ /^[^>]*>/
+
+            if auto_linked?($`, $')
               # do not change string; URL is already linked
               href
             else
@@ -570,18 +574,23 @@ def auto_link_urls(text, html_options = {})
         # Turns all email addresses into clickable links.  If a block is given,
         # each email is yielded and the result is used as the link text.
         def auto_link_email_addresses(text, html_options = {})
-          body = text.dup
-          text.gsub(/([\w\.!#\$%\-+.]+@[A-Za-z0-9\-]+(\.[A-Za-z0-9\-]+)+)/) do
-            text = $1
+          text.gsub(AUTO_EMAIL_RE) do
+            text = $&
 
-            if body.match(/<a\b[^>]*>(.*)(#{Regexp.escape(text)})(.*)<\/a>/)
+            if auto_linked?($`, $')
               text
             else
               display_text = (block_given?) ? yield(text) : text
               mail_to text, display_text, html_options
             end
           end
         end
+
+        # Detects already linked context or position in the middle of a tag
+        def auto_linked?(left, right)
+          (left =~ AUTO_LINK_CRE[0] and right =~ AUTO_LINK_CRE[1]) or
+            (left.rindex(AUTO_LINK_CRE[2]) and $' !~ AUTO_LINK_CRE[3])
+        end
     end
   end
 end

actionpack/test/template/text_helper_test.rb

@@ -296,6 +296,7 @@ def test_auto_linking
     assert_equal %(<p>Link #{link_result_with_options}</p>), auto_link("<p>Link #{link_raw}</p>", :all, {:target => "_blank"})
     assert_equal %(Go to #{link_result}.), auto_link(%(Go to #{link_raw}.))
     assert_equal %(<p>Go to #{link_result}, then say hello to #{email_result}.</p>), auto_link(%(<p>Go to #{link_raw}, then say hello to #{email_raw}.</p>))
+    assert_equal %(#{link_result} #{link_result}), auto_link(%(#{link_result} #{link_raw}))
 
     email2_raw    = '+david@loudthinking.com'
     email2_result = %{<a href="mailto:#{email2_raw}">#{email2_raw}</a>}
@@ -382,9 +383,24 @@ def test_auto_link_other_protocols
 
   def test_auto_link_already_linked
     linked1 = generate_result('Ruby On Rails', 'http://www.rubyonrails.com')
-    linked2 = generate_result('www.rubyonrails.com', 'http://www.rubyonrails.com')
+    linked2 = %('<a href="http://www.example.com">www.example.com</a>')
+    linked3 = %('<a href="http://www.example.com" rel="nofollow">www.example.com</a>')
+    linked4 = %('<a href="http://www.example.com"><b>www.example.com</b></a>')
+    linked5 = %('<a href="#close">close</a> <a href="http://www.example.com"><b>www.example.com</b></a>')
     assert_equal linked1, auto_link(linked1)
     assert_equal linked2, auto_link(linked2)
+    assert_equal linked3, auto_link(linked3)
+    assert_equal linked4, auto_link(linked4)
+    assert_equal linked5, auto_link(linked5)
+
+    linked_email = %Q(<a href="mailto:david@loudthinking.com">Mail me</a>)
+    assert_equal linked_email, auto_link(linked_email)
+  end
+
+  def test_auto_link_within_tags
+    link_raw    = 'http://www.rubyonrails.org/images/rails.png'
+    link_result = %Q(<img src="#{link_raw}" />)
+    assert_equal link_result, auto_link(link_result)
   end
 
   def test_auto_link_with_brackets
@@ -404,12 +420,6 @@ def test_auto_link_with_brackets
     assert_equal "{link: #{link3_result}}", auto_link("{link: #{link3_raw}}")
   end
 
-  def test_auto_link_in_tags
-    link_raw    = 'http://www.rubyonrails.org/images/rails.png'
-    link_result = %Q(<img src="#{link_raw}" />)
-    assert_equal link_result, auto_link(link_result)
-  end
-
   def test_auto_link_at_eol
     url1 = "http://api.rubyonrails.com/Foo.html"
     url2 = "http://www.ruby-doc.org/core/Bar.html"
@@ -423,6 +433,19 @@ def test_auto_link_with_block
 
     assert_equal %(<p><a href="#{url}">#{url[0...7]}...</a><br /><a href="mailto:#{email}">#{email[0...7]}...</a><br /></p>), auto_link("<p>#{url}<br />#{email}<br /></p>") { |url| truncate(url, :length => 10) }
   end
+
+  def test_auto_link_with_block_with_html
+    pic = "http://example.com/pic.png"
+    url = "http://example.com/album?a&b=c"
+
+    assert_equal %(My pic: <a href="#{pic}"><img src="#{pic}" width="160px"></a> -- full album here #{generate_result(url)}), auto_link("My pic: #{pic} -- full album here #{url}") { |link|
+      if link =~ /\.(jpg|gif|png|bmp|tif)$/i
+        raw %(<img src="#{link}" width="160px">)
+      else
+        link
+      end
+    }
+  end
 
   def test_auto_link_with_options_hash
     assert_dom_equal 'Welcome to my new blog at <a href="http://www.myblog.com/" class="menu" target="_blank">http://www.myblog.com/</a>. Please e-mail me at <a href="mailto:me@email.com" class="menu" target="_blank">me@email.com</a>.',