[rubocop#1117] Correct indentation around block comments

The earlier solution simply avoided auto-correcting every node that
contains a block comment. This solution indents as usual but leaves
block comments untouched.

lib/rubocop/cop/correctors/alignment_corrector.rb

@@ -17,9 +17,9 @@ def correct(processed_source, node, column_delta)
 
           @processed_source = processed_source
           expr = node.respond_to?(:loc) ? node.loc.expression : node
-          return if block_comment_within?(expr)
 
-          taboo_ranges = inside_string_ranges(node)
+          taboo_ranges = inside_string_ranges(node) +
+                         block_comment_ranges
 
           lambda do |corrector|
             each_line(expr) do |line_begin_pos|
@@ -79,9 +79,14 @@ def inside_regular_string_range(node)
           loc.begin.end.join(loc.end.begin)
         end
 
-        def block_comment_within?(expr)
-          processed_source.comments.select(&:document?).any? do |c|
-            within?(c.loc.expression, expr)
+        def block_comment_ranges
+          processed_source.comments.select(&:document?).map do |c|
+            range = c.loc.expression
+            if range.source.end_with?("\n")
+              range.adjust(end_pos: -1)
+            else
+              range
+            end
           end
         end
 

spec/rubocop/cop/alignment_corrector_spec.rb

@@ -115,5 +115,31 @@
         OUTPUT
       end
     end
+
+    context 'with block comments' do
+      it 'does not indent block comments' do
+        expect(autocorrect_source(<<~INPUT)).to eq(<<~OUTPUT)
+          # >> 2
+          begin
+            bar
+          =begin
+          Ancient
+          comment
+          =end
+            baz
+          end
+        INPUT
+          # >> 2
+            begin
+              bar
+          =begin
+          Ancient
+          comment
+          =end
+              baz
+            end
+        OUTPUT
+      end
+    end
   end
 end

spec/rubocop/cop/layout/indentation_width_spec.rb

@@ -248,27 +248,34 @@ class Test
           RUBY
         end
 
-        it 'does not correct in scopes that contain block comments' do
+        it 'does not indent block comments' do
           source = <<~RUBY
             module Foo
-            # The class has a block comment within, so it's not corrected.
             class Bar
             =begin
             This is a nice long
             comment
             which spans a few lines
+            and must not be indented
             =end
-            # The method has no block comment inside,
-            # but it's within a class that has a block
-            # comment, so it's not corrected either.
-            def baz
-            do_something
-            end
+              do_something # indented
             end
             end
           RUBY
 
-          expect(autocorrect_source(source)).to eq source
+          expect(autocorrect_source(source)).to eq <<~RUBY
+            module Foo
+              class Bar
+            =begin
+            This is a nice long
+            comment
+            which spans a few lines
+            and must not be indented
+            =end
+                do_something # indented
+              end
+            end
+          RUBY
         end
 
         it 'does not indent heredoc strings' do