more insertRow() bugs and fixes

First, a big thanks to Dave Cramer for working with me on the last
insertRow() issue I had--the patch works wonderfully!

Now, on to the next few things.

1. When you insert a row into a resultset that has no rows and then call
moveToCurrentRow(), you get a null pointer exception. Example code:

Statement stmt = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
ResultSet uprs = stmt.executeQuery("SELECT oid,* FROM school WHERE 1=0");
uprs.moveToInsertRow();
uprs.updateString("name", name);
uprs.insertRow();
uprs.moveToCurrentRow();

java.lang.ArrayIndexOutOfBoundsException: -1 < 0
at java.util.Vector.elementAt(Vector.java:437)
at
org.postgresql.jdbc2.AbstractJdbc2ResultSet.moveToCurrentRow(AbstractJdbc2Re
sultSet.java:667)

The cause of this is pretty straightforward. The offending line 667 in
AbstractJdbc2ResultSet.java is:

this_row = (byte[][]) rows.elementAt(current_row);

current_row is -1 because the current position is before any rows.

2. After moving onto the insert row, only a few of the resultset
cursor-moving functions clear the internal “onInsertRow” variable.
According to
http://java.sun.com/docs/books/tutorial/jdbc/jdbc2dot0/inserting.html :
“After you have called the method insertRow , you can start building another
row to be inserted, or you can move the cursor back to a result set row. You
can, for instance, invoke any of the methods that put the cursor on a
specific row, such as first , last , beforeFirst , afterLast , and absolute
. You can also use the methods previous , relative , and moveToCurrentRow.”

However, in the current driver, only first() and moveToCurrentRow() clear
the onInsertRow flag. This causes problems when you later try to update a
row in the same resultset. The functions that need to be modified that come
to mind are: last(), beforeFirst(), afterLast(), absolute(), previous(),
next(), and relative() (relative() uses absolute() internally, so I’ve
skipped putting any code in it).

I’ve included a patch to address these issues, but I’m still new to the
codebase (and my directory isn’t set up to compile), so it’ll need a good
looking-over.

Thanks again,
Joel