psql/pg_dump vs. dollar signs in identifiers

An example being discussed on the jdbc list led me to try this:

regression=# create table a$b$c (f1 int);
CREATE TABLE
regression=# \d a$b$c
Did not find any relation named "a$b$c".

It works if you use quotes:

regression=# \d "a$b$c"
Table "public.a$b$c"
Column | Type | Modifiers
--------+---------+-----------
f1 | integer |

The reason it doesn't work without quotes is that processSQLNamePattern()
thinks this:

* Inside double quotes, or at all times if force_escape is true,
* quote regexp special characters with a backslash to avoid
* regexp errors. Outside quotes, however, let them pass through
* as-is; this lets knowledgeable users build regexp expressions
* that are more powerful than shell-style patterns.

and of course $ is a regexp special character, so it bollixes up the
match.

Now, because we surround the pattern with ^...$ anyway, I can't offhand
see a use-case for putting $ with its regexp meaning into the pattern.
And since we do allow $ as a non-first character of identifiers, there
is a use-case for expecting it to be treated like an ordinary character.

So I'm thinking that $ ought to be quoted whether it's inside double
quotes or not. This change would affect psql's describe commands as
well as pg_dump -t and -n patterns.

Comments?

regards, tom lane