fix(pgmq): fix drop_queue overloading bug

ansible/files/postgresql_extension_custom_scripts/pgmq/after-create.sql

@@ -21,14 +21,16 @@ begin
     this update is backwards compatible with version 1.4.4 but should be removed once we're on
     physical backups everywhere
 */
--- Detach and delete the official function
-if extversion = '1.4.4' then
-  alter extension pgmq drop function pgmq.drop_queue;
-  drop function pgmq.drop_queue;
-else -- 1.5.1+
-  alter extension pgmq drop function pgmq.drop_queue(TEXT);
-  drop function pgmq.drop_queue(TEXT);
-end if;
+  -- detach both historical drop_queue signatures, if present as extension members
+  if to_regprocedure('pgmq.drop_queue(text)') is not null then
+    alter extension pgmq drop function pgmq.drop_queue(text);
+  end if;
+  if to_regprocedure('pgmq.drop_queue(text, boolean)') is not null then
+    alter extension pgmq drop function pgmq.drop_queue(text, boolean);
+  end if;
+
+  drop function if exists pgmq.drop_queue(text);
+  drop function if exists pgmq.drop_queue(text, boolean);
 
 -- Create and reattach the patched function
 CREATE FUNCTION pgmq.drop_queue(queue_name TEXT)
@@ -143,11 +145,17 @@ BEGIN
 END;
 $func$ LANGUAGE plpgsql;
 
-if extversion = '1.4.4' then
-  alter extension pgmq add function pgmq.drop_queue;
-else -- 1.5.1+
-  alter extension pgmq add function pgmq.drop_queue(TEXT);
-end if;
+  alter extension pgmq add function pgmq.drop_queue(text);
+
+-- compat shim, not reattached: keeps ALTER EXTENSION UPDATE from ever touching it
+CREATE OR REPLACE FUNCTION pgmq.drop_queue(queue_name TEXT, partitioned BOOLEAN)
+RETURNS BOOLEAN AS $shim$
+BEGIN
+    RETURN pgmq.drop_queue(queue_name);
+END;
+$shim$ LANGUAGE plpgsql;
+
+  alter function pgmq.drop_queue(text, boolean) owner to postgres;
 
 
   update pg_extension set extowner = 'postgres'::regrole where extname = 'pgmq';

ansible/files/postgresql_extension_custom_scripts/pgmq/before-create.sql

@@ -0,0 +1,4 @@
+-- clear a leftover drop_queue(text, boolean) compat shim from a prior
+-- install: it isn't an extension member, so DROP EXTENSION never removes it,
+-- and pgmq's own install script would otherwise collide with it
+drop function if exists pgmq.drop_queue(text, boolean);

nix/ext/tests/pgmq-drop-queue-overload.nix

@@ -0,0 +1,84 @@
+{ self, pkgs }:
+let
+  pname = "pgmq";
+  inherit (pkgs) lib;
+  system = pkgs.pkgsLinux.stdenv.hostPlatform.system;
+  testLib = import ./lib.nix { inherit self pkgs; };
+
+  installedExtension = self.legacyPackages.${system}."psql_15".exts."${pname}";
+  versions = installedExtension.versions;
+in
+pkgs.testers.runNixOSTest {
+  name = "pgmq-drop-queue-overload";
+  nodes.server =
+    { ... }:
+    {
+      imports = [
+        (testLib.makeSupabaseTestConfig {
+          majorVersion = "15";
+        })
+      ];
+    };
+  testScript =
+    { ... }:
+    let
+      versionList = lib.concatStringsSep ", " (map (v: ''"${v}"'') versions);
+    in
+    ''
+      versions = [${versionList}]
+
+      def sql(query):
+          return server.succeed(
+              "psql -U supabase_admin -d postgres -t -A -F',' -c \"" + query.replace('"', '\\"') + "\""
+          ).strip()
+
+      def drop_queue_overloads():
+          # owned flag first: pg_get_function_identity_arguments() can itself
+          # contain a comma ("queue_name text, partitioned boolean"), so put the
+          # single-char flag first and split on the first comma only.
+          out = sql(
+              "select (d.objid is not null), pg_get_function_identity_arguments(p.oid) "
+              "from pg_proc p "
+              "left join pg_depend d on d.objid = p.oid and d.deptype = 'e' "
+              "  and d.refobjid = (select oid from pg_extension where extname = 'pgmq') "
+              "where p.pronamespace = 'pgmq'::regnamespace and p.proname = 'drop_queue' "
+              "order by 2;"
+          )
+          return [line.split(",", 1) for line in out.splitlines() if line]
+
+      # every calling convention drop_queue has ever supported still works
+      def check_callers(qname):
+          sql(f"select pgmq.create('{qname}_a'); select pgmq.drop_queue('{qname}_a');")
+          sql(f"select pgmq.create('{qname}_b'); select pgmq.drop_queue('{qname}_b', false);")
+          # WRONG flag on purpose (queue isn't partitioned) - must still
+          # succeed, safely ignored in favour of pgmq.meta
+          sql(f"select pgmq.create('{qname}_c'); select pgmq.drop_queue('{qname}_c', true);")
+          sql(
+              f"select pgmq.create('{qname}_d'); "
+              f"select pgmq.drop_queue(queue_name => '{qname}_d', partitioned => true);"
+          )
+
+      start_all()
+      server.wait_for_unit("supabase-db-init.service")
+
+      # fresh install of each pinned version: check the overload split, then the callers
+      for version in versions:
+          with subtest(f"install pgmq {version}"):
+              server.succeed("psql -U supabase_admin -d postgres -c 'DROP EXTENSION IF EXISTS pgmq;'")
+              server.succeed(
+                  f"psql -U supabase_admin -d postgres -c \"CREATE EXTENSION pgmq WITH VERSION '{version}' CASCADE;\""
+              )
+
+              overloads = drop_queue_overloads()
+              print(f"[{version}] drop_queue overloads: {overloads}")
+              assert overloads == [
+                  ["t", "queue_name text"],
+                  ["f", "queue_name text, partitioned boolean"],
+              ], (
+                  f"[{version}] expected one extension-owned drop_queue(text) plus "
+                  f"an unattached drop_queue(text, boolean) compat shim, got: {overloads}"
+              )
+
+              check_callers(f"q_{version.replace('.', '_')}")
+    '';
+}

nix/tests/expected/pgmq.out

@@ -175,7 +175,6 @@ order by
  pgmq        | delete                        | postgres
  pgmq        | detach_archive                | postgres
  pgmq        | drop_queue                    | postgres
- pgmq        | drop_queue                    | postgres
  pgmq        | format_table_name             | postgres
  pgmq        | list_queues                   | postgres
  pgmq        | metrics                       | postgres
@@ -198,7 +197,7 @@ order by
  pgmq        | send_batch                    | postgres
  pgmq        | set_vt                        | postgres
  pgmq        | validate_queue_name           | postgres
-(40 rows)
+(39 rows)
 
 -- assert search_path is preserved after after-create script is run
 show search_path;