Don't blindly call blame_file! on exceptions in ActiveSupport::Dependencies::Loadable

It is possible under some environments to receive an Exception that is
not extended with Blamable (e.g. JRuby).
ActiveSupport::Dependencies::Loadable#load_dependency blindly call
blame_file! on the exception which throws it's own NoMethodError
exception and hides the original Exception.

This commit fixes #9521

2 files changed, 13 insertions, 0 deletions

diff --git a/activesupport/test/dependencies/raises_exception_without_blame_file.rb b/activesupport/test/dependencies/raises_exception_without_blame_file.rb
new file mode 100644
index 0000000000..4b2da6ff30
--- /dev/null
+++ b/activesupport/test/dependencies/raises_exception_without_blame_file.rb
@@ -0,0 +1,5 @@
+exception = Exception.new('I am not blamable!')
+class << exception
+  undef_method(:blame_file!)
+end
+raise exception
diff --git a/activesupport/test/dependencies_test.rb b/activesupport/test/dependencies_test.rb
index 4b1426bb2e..68b6cc6e8c 100644
--- a/activesupport/test/dependencies_test.rb
+++ b/activesupport/test/dependencies_test.rb
@@ -76,6 +76,14 @@ class DependenciesTest < ActiveSupport::TestCase
     end
   end
 
+  def test_dependency_which_raises_doesnt_blindly_call_blame_file!
+    with_loading do
+      filename = 'dependencies/raises_exception_without_blame_file'
+
+      assert_raises(Exception) { require_dependency filename }
+    end
+  end
+
   def test_warnings_should_be_enabled_on_first_load
     with_loading 'dependencies' do
       old_warnings, ActiveSupport::Dependencies.warnings_on_first_load = ActiveSupport::Dependencies.warnings_on_first_load, true