The 1979 ICC Trophy counted as the qualifier for non-test nations to get into the World Cup that year. Denmark were the only team of the 15 to win all their qualifying games* but had a stinker in the semi, losing very, very badly to Sri Lanka in the semi. Sri Lanka had a 2-1 record in the group (one game abandoned), and only made it to the semis on net run rate, but after rolling Denmark they beat Canada in the final, and then in the CWC, finished ahead of India in their group, and within three years were a test nation.
So given that winning the semi would have been enough to qualify for the World Cup, what if Denmark beat Sri Lanka that day?
*Bermuda were also undefeated in their group, with one game abandoned.