Comments do not show up in diffs

1. Have a look at http://codereview.qt-project.org/8510 , Patch set 22, file tests/system/README .
   The file contains four comments.
2. Above the patch sets, select "Old Version History: 22"
3. Look at the diff of tests/system/README in Patch set 23.
4. Select "Context: 10 lines".
   Only two of the comments are being shown.

All comments should be shown. Usually these are there because someone wanted a change. As a user I want to see if someone ignored such a suggestion.