[Fix rubocop#9333] Fix an error for Style/IfInsideElse

Fixes rubocop#9333.

This PR fixes an error for `Style/IfInsideElse`
when using a modifier `if` nested inside an `else` after `elsif`.

changelog/fix_an_error_for_style_if_inside_else.md

@@ -0,0 +1 @@
+* [#9333](https://github.com/rubocop-hq/rubocop/issues/9333): Fix an error for `Style/IfInsideElse` when using a modifier `if` nested inside an `else` after `elsif`. ([@koic][])

lib/rubocop/cop/style/if_inside_else.rb

@@ -82,12 +82,10 @@ def on_if(node)
         def autocorrect(corrector, node)
           if node.modifier_form?
             correct_to_elsif_from_modifier_form(corrector, node)
-            end_range = node.parent.loc.end
           else
             correct_to_elsif_from_if_inside_else_form(corrector, node, node.condition)
-            end_range = node.loc.end
           end
-          corrector.remove(range_by_whole_lines(end_range, include_final_newline: true))
+          corrector.remove(range_by_whole_lines(find_end_range(node), include_final_newline: true))
           corrector.remove(
             range_by_whole_lines(node.if_branch.source_range, include_final_newline: true)
           )
@@ -110,6 +108,13 @@ def correct_to_elsif_from_if_inside_else_form(corrector, node, condition)
           corrector.remove(condition)
         end
 
+        def find_end_range(node)
+          end_range = node.loc.end
+          return end_range if end_range
+
+          find_end_range(node.parent)
+        end
+
         def allow_if_modifier_in_else_branch?(else_branch)
           allow_if_modifier? && else_branch&.modifier_form?
         end

spec/rubocop/cop/style/if_inside_else_spec.rb

@@ -84,6 +84,29 @@
     RUBY
   end
 
+  it 'catches a modifier if nested inside an else after elsif' do
+    expect_offense(<<~RUBY)
+      if a
+        blah
+      elsif b
+        foo
+      else
+        bar if condition
+            ^^ Convert `if` nested inside `else` to `elsif`.
+      end
+    RUBY
+
+    expect_correction(<<~RUBY)
+      if a
+        blah
+      elsif b
+        foo
+      elsif condition
+        bar
+      end
+    RUBY
+  end
+
   context 'when AllowIfModifier is false' do
     it 'catches a modifier if nested inside an else' do
       expect_offense(<<~RUBY)