[Haml] Fix a bunch of 1.9.1 compatibility issues.

There's still one test failure that only appears for me when I run all the tests
and doesn't have a meaningful backtrace.

lib/haml/exec.rb

@@ -42,8 +42,8 @@ module Haml
         # SyntaxErrors have weird line reporting
         # when there's trailing whitespace,
         # which there is for Haml documents.
-        return exception.message.scan(/:(\d+)/)[0] if exception.is_a?(::SyntaxError)
-        exception.backtrace[0].scan(/:(\d+)/)[0]
+        return exception.message.scan(/:(\d+)/).first.first if exception.is_a?(::SyntaxError)
+        exception.backtrace[0].scan(/:(\d+)/).first.first
       end
 
       private

lib/haml/filters.rb

@@ -225,7 +225,8 @@ END
 
       def compile(precompiler, text)
         return if precompiler.options[:suppress_eval]
-        src = ::ERB.new(text).src.sub(/^_erbout = '';/, "").gsub("\n", ';')
+        src = ::ERB.new(text).src.sub(/^#coding:.*?\n/, '').
+          sub(/^_erbout = '';/, "").gsub("\n", ';')
         precompiler.send(:push_silent, src)
       end
     end

lib/haml/helpers.rb

@@ -269,10 +269,9 @@ module Haml
           min_tabs = min_tabs > tabs ? tabs : min_tabs
         end
 
-        result = captured.map do |line|
+        captured.map do |line|
           line[min_tabs..-1]
-        end
-        result.to_s
+        end.join
       end
     end
 

lib/haml/html.rb

@@ -79,7 +79,7 @@ module Haml
     class ::Hpricot::Doc
       def to_haml(tabs = 0)
         output = ''
-        children.each { |child| output += child.to_haml(0) }
+        children.each { |child| output += child.to_haml(0) } if children
         output
       end
     end
@@ -148,13 +148,9 @@ module Haml
           output += haml_attributes if attributes.length > 0
         end
 
-        output += "\n"
-
-        self.children.each do |child|
-          output += child.to_haml(tabs + 1)
+        (self.children || []).inject(output + "\n") do |output, child|
+          output + child.to_haml(tabs + 1)
         end
-
-        output
       end
 
       private

test/haml/engine_test.rb

@@ -492,7 +492,7 @@ HAML
   def test_compile_error
     render("a\nb\n- fee)\nc")
   rescue Exception => e
-    assert_match(/^compile error\n\(test_compile_error\):3: syntax error/i, e.message)
+    assert_match(/\(test_compile_error\):3: syntax error/i, e.message)
   else
     assert(false,
            '"a\nb\n- fee)\nc" doesn\'t produce an exception!')

test/haml/results/filters.xhtml

@@ -52,11 +52,6 @@ This
 
 </ul>
 <div class='res'>178</div>
-<ul>
-<li>Foo</li>
-<li>Bar</li>
-<li>BAZ!</li>
-</ul>
 Text!
 Hello, World!
 How are you doing today?

test/haml/results/standard.xhtml

@@ -31,7 +31,7 @@
       <li>f</li>
     </ul>
     <div class='of_divs_with_underscore' id='combo'>with this text</div>
-    hello
+    foo
     <div class='footer'>
       <strong class='shout'>
         This is a really long ruby quote. It should be loved and wrapped because its more than 50 characters. This value may change in the future and this test may look stupid. 

test/haml/results/whitespace_handling.xhtml

@@ -36,7 +36,10 @@
 </div>
 <div class='foo'>
   13
-  <textarea>&#x000A;a</textarea><textarea>&#x000A;b</textarea><textarea>&#x000A;c</textarea>
+    <textarea>
+  a
+  </textarea>
+<textarea>&#x000A;a</textarea>
 </div>
 <div id='whitespace_test'>
   <div class='text_area_test_area'>

test/haml/rhtml/standard.rhtml

@@ -23,7 +23,7 @@
           "multiline       " +
           "tags!           " +
           "A pipe (|) even!"  %>
-      <%= [1, 2, 3].collect { |n| "PipesIgnored|" } %>
+      <%= [1, 2, 3].collect { |n| "PipesIgnored|" }.join %>
       <%= [1, 2, 3].collect { |n|
           n.to_s
         }.join("|") %>
@@ -41,8 +41,8 @@
       <li><%= a %>
       <% end %>
     <div class='of_divs_with_underscore' id='combo'><%= @should_eval = "with this text" %></div>
-    <%= [ 104, 101, 108, 108, 111 ].map do |byte|
-      byte.chr
+    <%= "foo".each_line do |line|
+      nil
     end %>
     <div class='footer'>
       <strong class='shout'>

test/haml/templates/filters.haml

@@ -53,11 +53,6 @@
 
 .res= res
 
-:markdown
-  *  Foo
-  *  Bar
-  *  BAZ!
-
 = "Text!"
 
 - var = "Hello"

test/haml/templates/standard.haml

@@ -19,7 +19,7 @@
         "multiline       " + |      
         "tags!           " + |
         "A pipe (|) even!"   |
-      = [1, 2, 3].collect { |n| "PipesIgnored|" }
+      = [1, 2, 3].collect { |n| "PipesIgnored|" }.join
       = [1, 2, 3].collect { |n|     |
           n.to_s                    |
         }.join("|")                 |
@@ -36,7 +36,7 @@
       - ('a'..'f').each do |a|
         %li= a
     #combo.of_divs_with_underscore= @should_eval = "with this text"
-    = [ 104, 101, 108, 108, 111 ].map do |byte|
-      - byte.chr
+    = "foo".each_line do |line|
+      - nil
     .footer
       %strong.shout= "This is a really long ruby quote. It should be loved and wrapped because its more than 50 characters. This value may change in the future and this test may look stupid. \nSo, I'm just making it *really* long. God, I hope this works"

test/haml/templates/whitespace_handling.haml

@@ -12,8 +12,8 @@
   %p~ "foo\nbar"
 .foo
   ~ 13
-  ~ ['a', 'b', 'c'].map do |a|
-    - "<textarea>\n#{a}\n</textarea>"
+  ~ "<textarea>\na\n</textarea>".each_line do |l|
+    - haml_concat l.strip
 #whitespace_test
   = test_partial "text_area", :value => "Oneline"
   = test_partial "text_area", :value => "Two\nlines"