Doc: explain how to test ADMIN privilege with pg_has_role().

This has always been possible, but the syntax is a bit obscure,
and our user-facing docs were not very helpful.  Spell it out
more clearly.

Per complaint from Dominique Devienne.  Back-patch to
all supported branches.

Discussion: https://postgr.es/m/CAFCRh-8JNEy+dV4SXFOrWca50u+d=--TO4cq=+ac1oBtfJy4AA@mail.gmail.com

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index fd877a4ea813091ad0ba11bbeffb3aee84ad7620..6ee09fc288acdccec2ed7daa62c35b4f09861887 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -22594,6 +22594,10 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
         the role (that is, the right to do SET ROLE), while
         USAGE denotes whether the privileges of the role
         are immediately available without doing SET ROLE.
+        WITH ADMIN OPTION or WITH GRANT
+        OPTION can be added to either of these privilege types to
+        test whether the ADMIN privilege is held (all
+        four spellings test the same thing).
         This function does not allow the special case of
         setting user to public,
         because the PUBLIC pseudo-role can never be a member of real roles.