Prevents position update for image diff notes

app/models/diff_note.rb

@@ -18,7 +18,8 @@ class DiffNote < Note
   validate :positions_complete
   validate :verify_supported
 
-  before_validation :set_original_position, :update_position, on: :create
+  before_validation :set_original_position, on: :create
+  before_validation :update_position, on: :create, if: :on_text?
   before_validation :set_line_code
   after_save :keep_around_commits
 

changelogs/unreleased/issue_40058.yml

@@ -0,0 +1,5 @@
+---
+title: Prevents position update for image diff notes
+merge_request:
+author:
+type: fixed

spec/models/diff_note_spec.rb

@@ -283,6 +283,12 @@ describe DiffNote do
         expect(diff_line).to be nil
         expect(subject).to be_valid
       end
+
+      it "does not update the position" do
+        expect(subject).not_to receive(:update_position)
+
+        subject.save
+      end
     end
 
     it "returns true for on_image?" do