Adds a tricky user to test

This allows us to test aclitem encoding
with tricky SQL identifiers. The user actually
has to exist, or the aclitem will be incorrect.

.travis.yml

@@ -36,6 +36,7 @@ before_script:
   - psql -U postgres -c "create user pgx_ssl SUPERUSER PASSWORD 'secret'"
   - psql -U postgres -c "create user pgx_md5 SUPERUSER PASSWORD 'secret'"
   - psql -U postgres -c "create user pgx_pw  SUPERUSER PASSWORD 'secret'"
+  - psql -U postgres -c "create user \" tricky, ' } \"\" \\ test user \" superuser password 'secret'"
 
 install:
   - go get -u github.com/shopspring/decimal

README.md

@@ -66,6 +66,7 @@ To setup the normal test environment, first install these dependencies:
 Then run the following SQL:
 
     create user pgx_md5 password 'secret';
+    create user " tricky, ' } "" \ test user " superuser password 'secret';
     create database pgx_test;
 
 Connect to database pgx_test and run:

values.go

@@ -265,7 +265,18 @@ func (n NullString) Encode(w *WriteBuf, oid Oid) error {
 	return encodeString(w, oid, n.String)
 }
 
-// AclItem is used for PostgreSQL's aclitem data type.
+// AclItem is used for PostgreSQL's aclitem data type. A sample aclitem
+// might look like this:
+//
+//	postgres=arwdDxt/postgres
+//
+// Note, however, that because the user/role name part of an aclitem is
+// an identifier, it follows all the usual formatting rules for SQL
+// identifiers: if it contains spaces and other special characters,
+// it should appear in double-quotes:
+//
+//	postgres=arwdDxt/"role with spaces"
+//
 type AclItem string
 
 // NullAclItem represents a pgx.AclItem that may be null. NullAclItem implements the

values_test.go

@@ -600,6 +600,7 @@ func TestNullX(t *testing.T) {
 		{"select $1::\"char\"", []interface{}{pgx.NullChar{Char: 255, Valid: true}}, []interface{}{&actual.c}, allTypes{c: pgx.NullChar{Char: 255, Valid: true}}},
 		{"select $1::name", []interface{}{pgx.NullName{Name: "foo", Valid: true}}, []interface{}{&actual.n}, allTypes{n: pgx.NullName{Name: "foo", Valid: true}}},
 		{"select $1::name", []interface{}{pgx.NullName{Name: "foo", Valid: false}}, []interface{}{&actual.n}, allTypes{n: pgx.NullName{Name: "", Valid: false}}},
+		{"select $1::aclitem", []interface{}{pgx.NullAclItem{AclItem: `postgres=arwdDxt/" tricky, ' } "" \ test user "`, Valid: true}}, []interface{}{&actual.a}, allTypes{a: pgx.NullAclItem{AclItem: `postgres=arwdDxt/" tricky, ' } "" \ test user "`, Valid: true}}},
 		{"select $1::aclitem", []interface{}{pgx.NullAclItem{AclItem: "postgres=arwdDxt/postgres", Valid: true}}, []interface{}{&actual.a}, allTypes{a: pgx.NullAclItem{AclItem: "postgres=arwdDxt/postgres", Valid: true}}},
 		{"select $1::aclitem", []interface{}{pgx.NullAclItem{AclItem: "postgres=arwdDxt/postgres", Valid: false}}, []interface{}{&actual.a}, allTypes{a: pgx.NullAclItem{AclItem: "", Valid: false}}},
 		{"select $1::cid", []interface{}{pgx.NullCid{Cid: 1, Valid: true}}, []interface{}{&actual.cid}, allTypes{cid: pgx.NullCid{Cid: 1, Valid: true}}},