.dump generates invalid NULL in output for tables that have a UNIQUE constraint

[Doug Stevenson]

Run the following SQL, noting the UNIQUE:

CREATE TABLE example_gid_counts (
    gid TEXT UNIQUE NOT NULL,
    row_count INTEGER NOT NULL
);

Then run .dump:

CREATE TABLE example_gid_counts (
gid TEXT UNIQUE NOT NULL,
row_count INTEGER NOT NULL
);
NULL

Note the extra trailing NULL in the output, which causes problems when loaded back into a database.

Without UNIQUE it works as expected:

CREATE TABLE example_gid_counts (
    gid TEXT NOT NULL,
    row_count INTEGER NOT NULL
);

.dump:

CREATE TABLE example_gid_counts (
gid TEXT NOT NULL,
row_count INTEGER NOT NULL
);