Who were Josiah's sons, and why does Zedekiah come twice?

This chapter names four: "the firstborn Johanan, the second Jehoiakim, the third Zedekiah, and the fourth Shallum" (3:15). The next verse has "The sons of Jehoiakim: Jeconiah his son, and Zedekiah his son" (3:16), so a Zedekiah comes in both verses. 2 Kings tells of "Jehoahaz the son of Josiah" (2 Kings 23:30), of "Eliakim the son of Josiah", whose name was changed to Jehoiakim (2 Kings 23:34), and of Mattaniah, "Jehoiachin’s father’s brother", whose name was changed to Zedekiah (2 Kings 24:17). 2 Chronicles says Nebuchadnezzar brought Jehoiachin to Babylon "and made Zedekiah his brother king over Judah and Jerusalem" (2 Chronicles 36:10). Jeremiah speaks of "Shallum the son of Josiah, king of Judah, who reigned instead of Josiah his father" (Jeremiah 22:11), and 2 Kings says the people made Jehoahaz "king in his father’s place" (2 Kings 23:30). Kings names no son of Josiah called Johanan (tap Johanan). The Bible doesn't say how these lists fit together, and they are left here as they stand.