https://sourceforge.net/p/mingw/bugs/21/ has preformatted sections but the original classic version looked like http://screencast.com/t/oCRcZFTc Original incorrect escaping aside, this shows a failure for the upgrade script to convert all syntax properly. See more details at https://sourceforge.net/p/allura/tickets/5679/#ec93/64b7
allura:db/5805
ForgeBlog/forgeblog/tests/test_commands.py passes as does tests/test_migrate.py in forge-classic (which also exercises this functionality).
Below is the raw text to use as a full test case. Paste it into a classic project ticket and make sure copy/paste preserves it as tabs. Migrate the project and allura should look the same as classic did (no indentation, no preformatting).