Default $bootstrap-sass-asset-helper to true only if asset helper is

defined.
Thanks @cimmanon! See also: http://stackoverflow.com/questions/20706908/test-whether-a-sass-function-is-defined

README.md

@@ -59,12 +59,7 @@ Require the gem, and load paths and Sass helpers will be configured automaticall
 require 'bootstrap-sass'
 ```
 
-When using outside ruby (e.g. as a bower package), disable ruby asset lookup helper:
-
-```sass
-$bootstrap-sass-asset-helper: false
-```
-
+You can use bootstrap-sass as a Bower package as well.
 
 #### JS and fonts
 

lib/bootstrap-sass/sass_functions.rb

@@ -13,6 +13,7 @@ module Sass::Script::Functions
   declare :twbs_image_path, [:source]
 
   def twbs_asset_path(source, type)
+    return Sass::Script::String.new('', :string) if source.to_s.empty?
     url = if Bootstrap.asset_pipeline? && (context = sprockets_context)
             context.send(:"#{type}_path", source.value)
           elsif Bootstrap.compass?
@@ -23,7 +24,7 @@ module Sass::Script::Functions
     url ||= source.value.gsub('"', '')
     Sass::Script::String.new(url, :string)
   end
-  declare :twbs_asset_path, [:source]
+  declare :twbs_asset_path, [:source, :type]
 
   unless Sass::Script::Functions.instance_methods.include?(:ie_hex_str)
     # polyfill sass < 3.2.6 (taken from sass 3.2.12):

tasks/converter/less_conversion.rb

@@ -74,8 +74,9 @@ class Converter
           when 'variables.less'
             file = insert_default_vars(file)
             file = <<-SCSS + file
-// bootstrap specific variable. set to false if not using ruby + asset pipeline / compass.
-$bootstrap-sass-asset-helper: true !default;
+// whether to use bootstrap-sass asset pipeline / compass integration
+// defaults to true if twbs-font-path function is present.
+$bootstrap-sass-asset-helper: (twbs-font-path('') != unquote("twbs-font-path('')")) !default;
             SCSS
             file = replace_all file, /(\$icon-font-path:).*(!default)/, '\1 "bootstrap/" \2'
           when 'close.less'

tasks/converter/network.rb

@@ -87,6 +87,7 @@ class Converter
 
     # get sha of the branch (= the latest commit)
     def get_branch_sha
+      return @branch if @branch =~ /[0-9a-f]+/
       cmd = "git ls-remote '#@repo_url' | awk '/#@branch/ {print $1}'"
       puts cmd
       @branch_sha ||= %x[#{cmd}].chomp
@@ -107,4 +108,4 @@ class Converter
       JSON.parse get_file(url)
     end
   end
-end
+end

vendor/assets/stylesheets/bootstrap/_variables.scss

@@ -1,5 +1,6 @@
-// bootstrap specific variable. set to false if not using ruby + asset pipeline / compass.
-$bootstrap-sass-asset-helper: true !default;
+// whether to use bootstrap-sass asset pipeline / compass integration
+// defaults to true if twbs-font-path function is present.
+$bootstrap-sass-asset-helper: (twbs-font-path('') != unquote("twbs-font-path('')")) !default;
 //
 // Variables
 // --------------------------------------------------