[Sass] Make 1px/2px compile to that, literally, when necessary for CSS compatibility.

lib/sass/script/number.rb

@@ -25,6 +25,8 @@ module Sass::Script
     # @return [Array<String>]
     attr_reader :denominator_units
 
+    attr_accessor :original
+
     # The precision with which numbers will be printed to CSS files.
     # For example, if this is `1000.0`,
     # `3.1415926` will be printed as `3.142`.
@@ -134,7 +136,9 @@ module Sass::Script
     # @return [Literal] The result of the operation
     def div(other)
       if other.is_a? Number
-        operate(other, :/)
+        res = operate(other, :/)
+        res.original = "#{self.original}/#{other.original}" if self.original && other.original
+        res
       else
         super
       end
@@ -221,6 +225,7 @@ module Sass::Script
     # @raise [Sass::SyntaxError] if this number has units that can't be used in CSS
     #   (e.g. `px*in`)
     def to_s
+      return original if original
       raise Sass::SyntaxError.new("#{inspect} isn't a valid CSS value.") unless legal_units?
       inspect
     end

lib/sass/script/parser.rb

@@ -262,9 +262,13 @@ RUBY
 
       def paren
         return variable unless try_tok(:lparen)
+        was_in_parens = @in_parens
+        @in_parens = true
         e = assert_expr(:expr)
         assert_tok(:rparen)
         return e
+      ensure
+        @in_parens = was_in_parens
       end
 
       def variable
@@ -273,7 +277,7 @@ RUBY
       end
 
       def string
-        return literal unless first = try_tok(:string)
+        return number unless first = try_tok(:string)
         return first.value unless try_tok(:begin_interpolation)
         line = @lexer.line
         mid = parse_interpolated
@@ -283,8 +287,15 @@ RUBY
         op
       end
 
+      def number
+        return literal unless tok = try_tok(:number)
+        num = tok.value
+        num.original = num.to_s unless @in_parens
+        num
+      end
+
       def literal
-        (t = try_tok(:number, :color, :bool)) && (return t.value)
+        (t = try_tok(:color, :bool)) && (return t.value)
       end
 
       # It would be possible to have unified #assert and #try methods,

lib/sass/script/variable.rb

@@ -36,8 +36,12 @@ module Sass
       # @return [Literal] The SassScript object that is the value of the variable
       # @raise [Sass::SyntaxError] if the variable is undefined
       def _perform(environment)
-        (val = environment.var(name)) && (return val)
+        raise SyntaxError.new("Undefined variable: \"$#{name}\".") unless val = environment.var(name)
-        raise SyntaxError.new("Undefined variable: \"$#{name}\".")
+        if val.is_a?(Number)
+          val = val.dup
+          val.original = nil
+        end
+        return val
       end
     end
   end

test/sass/script_test.rb

@@ -182,8 +182,8 @@ SASS
     assert_equal "2", resolve("1 + 1")
     assert_equal "0", resolve("1 - 1")
     assert_equal "8", resolve("2 * 4")
-    assert_equal "0.5", resolve("2 / 4")
+    assert_equal "0.5", resolve("(2 / 4)")
-    assert_equal "2", resolve("4 / 2")
+    assert_equal "2", resolve("(4 / 2)")
 
     assert_equal "-1", resolve("-1")
   end

test/sass/scss/css_test.rb

@@ -297,7 +297,7 @@ SCSS
     assert_parses <<SCSS
 foo {
   a: foo bar baz;
-  b: foo, #abc, -12;
+  b: foo, #aabbcc, -12;
   c: 1px/2px/-3px;
   d: foo bar, baz/bang; }
 SCSS

test/sass/templates/script.sass

@@ -78,8 +78,8 @@ $complex = 1px/1em
     
 #div
   :num
-    :num= 10 / 3.0
+    :num= (10 / 3.0)
-    :num2= 10 / 3
+    :num2= (10 / 3)
   :col
     :num= #12468a / 2
     :col= #abcdef / #0f0f0f