New nullness error in 3.32 on if/else condition

[jpschewe]

This code was fine with 3.31 and I don't understand how prep can be null after the if/else statements as it's assigned in both branches.

import java.sql.PreparedStatement;
import java.sql.Connection;
import java.sql.SQLException;

import org.checkerframework.checker.nullness.qual.Nullable;

public class IfConditionNullness {

  private @Nullable PreparedStatement prep = null;
  
  public static final int NON_PERFORMANCE_RUN_NUMBER = -1;
  
  private void createResultSet(final Connection connection,
                               final int tournament,
                               final String categoryName)
    throws SQLException {
    if (NON_PERFORMANCE_RUN_NUMBER == 4) {
      prep = connection.prepareStatement("SELECT * FROM "
                                         + categoryName
                                         + " WHERE TeamNumber = ? AND Tournament = ?");
    } else {
      prep = connection.prepareStatement("SELECT * FROM "
                                         + categoryName
                                         + " WHERE TeamNumber = ? AND Tournament = ? AND RunNumber = ?");
      prep.setInt(3, 5);
    }
    prep.setInt(1, 2);
  }
}

The output is

IfConditionNullness.java:29: error: [dereference.of.nullable] dereference of possibly-null reference prep
    prep.setInt(1, 2);
    ^

[smillst]

This code was fine with 3.31 and I don't understand how prep can be null after the if/else statements as it's assigned in both branches.

prep.setInt(3, 5) could set prep to null. I could write an example like I did here: #5717 (comment).

[mernst]

In this particular case, you could annotate prep as @MonotonicNonNull rather than @Nullable (assuming it is never set to null except at its declaration). See https://checkerframework.org/manual/#type-refinement-purity .

[jpschewe]

It is set to null in other places, so I can't use @MonotonicNonNull.

Solved with answer at #5717 (comment)