BUG #5390: pg_dump does not check/include additional schema dependencies when writing schema/search path

The following bug has been logged online:

Bug reference:      5390
Logged by:          Timothy Seever
Email address:      tim.seever@gmail.com
PostgreSQL version: 8.3.5, others
Operating system:   Linux/RHEL5.2
Description:        pg_dump does not check/include additional schema
dependencies when writing schema/search path
Details:

To reproduce:

1. Create schema A
2. Create schema B
3. Create function in schema A which depends on something in schema B
without specifying it (i.e. the connected user has B included in the
search_path, and the function A.xyz() has something like   val := yyz();
where yyz is actually B.yyz.
4. This works properly in place due to the search path...  however upon
dumping/restoring, pg_dump only specifies the single schema+public before
each section, so it will fail to add A.xyz()/view/etc leading to cascaded
missing items.