Merge pull request #38059 from eugeneius/source_extract_encode_template

Encode template source before extracting lines

actionpack/test/dispatch/debug_exceptions_test.rb

@@ -61,7 +61,7 @@ class DebugExceptionsTest < ActionDispatch::IntegrationTest
     def call(env)
       env["action_dispatch.show_detailed_exceptions"] = @detailed
       req = ActionDispatch::Request.new(env)
-      template = ActionView::Template.new(File.read(__FILE__), __FILE__, ActionView::Template::Handlers::Raw.new, format: :html, locals: [])
+      template = ActionView::Template.new(File.binread(__FILE__), __FILE__, ActionView::Template::Handlers::Raw.new, format: :html, locals: [])
 
       case req.path
       when "/pass"
@@ -118,6 +118,12 @@ class DebugExceptionsTest < ActionDispatch::IntegrationTest
         raise CustomActionableError
       when %r{/nil_annoted_source_code_error}
         method_that_raises_nil_annoted_source_code
+      when "/utf8_template_error"
+        begin
+          eval "“fancy string”"
+        rescue Exception
+          raise ActionView::Template::Error.new(template)
+        end
       else
         raise "puke!"
       end
@@ -686,4 +692,17 @@ class DebugExceptionsTest < ActionDispatch::IntegrationTest
     assert_select "header h1", /DebugExceptionsTest::Boomer::NilAnnotedSourceCodeError/
     assert_select "#container h2", /nil annoted_source_code/
   end
+
+  test "debug exceptions app shows diagnostics for template errors that contain UTF-8 characters" do
+    @app = DevelopmentApp
+
+    io = StringIO.new
+    logger = ActiveSupport::Logger.new(io)
+
+    get "/utf8_template_error", headers: { "action_dispatch.logger" => logger }
+
+    assert_response 500
+    assert_select "#container p", /Showing #{__FILE__} where line #\d+ raised/
+    assert_select "#container code", /undefined local variable or method `string”'/
+  end
 end

actionview/lib/action_view/template/error.rb

@@ -85,7 +85,7 @@ module ActionView
         return [] unless num = line_number
         num = num.to_i
 
-        source_code = @template.source.split("\n")
+        source_code = @template.encode!.split("\n")
 
         start_on_line = [ num - SOURCE_CODE_RADIUS - 1, 0 ].max
         end_on_line   = [ num + SOURCE_CODE_RADIUS - 1, source_code.length].min