test case for RT#96878 : inserting into a contentless FTS table

OK without bind values
NOK with bind values ("constraint failed")
In the end, it's not really a bug, but rather a matter of usage pattern

MANIFEST

@@ -105,6 +105,7 @@ t/rt_77724_primary_key_with_a_whitespace.t
 t/rt_78833_utf8_flag_for_column_names.t
 t/rt_81536_multi_column_primary_key_info.t
 t/rt_88228_sqlite_3_8_0_crash.t
+t/rt_96878_fts_contentless_table.t
 typemap
 util/getsqlite.pl
 xt/meta.t

t/rt_96878_fts_contentless_table.t

@@ -0,0 +1,58 @@
+#!/usr/bin/perl
+
+# In a contentless FTS table, the columns are hidden from the schema,
+# and therefore SQLite has no information to infer column types, so
+# these are typed as SQLITE_NULL ... and this type conflicts with the
+# constraint on the 'docid' column. So we have to explicitly type that
+# column, using a CAST expression or a call to bind_param().
+
+# TMP HACK
+use lib "..";
+use lib "../blib/arch";
+use lib "../lib";
+
+
+use strict;
+BEGIN {
+	$|  = 1;
+	$^W = 1;
+}
+
+use t::lib::Test;
+use Test::More;
+use DBI qw/SQL_INTEGER/;
+plan tests => 8;
+use Test::NoWarnings;
+
+my $dbh = connect_ok(RaiseError => 1, AutoCommit => 1);
+
+# $dbh->trace(15);
+
+my $sql = q{CREATE VIRTUAL TABLE foo USING fts4 (content="", a, b)};
+ok( $dbh->do($sql), 'CREATE TABLE' );
+
+
+ok($dbh->do("INSERT INTO foo(docid, a, b) VALUES(1, 'a', 'b')"),
+   "insert without bind");
+
+# The following yields a constraint error because docid is improperly typed
+# $dbh->do("INSERT INTO foo(docid, a, b) VALUES(?, ?, ?)", {}, qw/2 aa bb/);
+
+# This works, thanks to the cast expression
+ok($dbh->do("INSERT INTO foo(docid, a, b) VALUES(CAST(? AS INTEGER), ?, ?)",
+            {}, qw/2 aa bb/),
+   "insert with bind and cast");
+
+# This also works, thanks to the bind_param() call
+my $sth = $dbh->prepare("INSERT INTO foo(docid, a, b) VALUES(?, ?, ?)");
+$sth->bind_param(1, 3, SQL_INTEGER);
+$sth->bind_param(2, "aaa");
+$sth->bind_param(3, "bbb");
+ok($sth->execute(),
+   "insert with bind_param and explicit type ");
+
+# Check that all terms were properly inserted
+ok( $dbh->do("CREATE VIRTUAL TABLE foo_aux USING fts4aux(foo)"), 'FTS4AUX');
+my $data = $dbh->selectcol_arrayref("select term from foo_aux where col='*'");
+is_deeply ([sort @$data], [qw/a aa aaa b bb bbb/], "terms properly indexed");
+