Index: openacs-4/packages/acs-tcl/tcl/apm-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/apm-procs.tcl,v
diff -u -N -r1.114.2.13 -r1.114.2.14
--- openacs-4/packages/acs-tcl/tcl/apm-procs.tcl	13 Jul 2020 12:02:33 -0000	1.114.2.13
+++ openacs-4/packages/acs-tcl/tcl/apm-procs.tcl	1 Sep 2020 17:31:32 -0000	1.114.2.14
@@ -993,9 +993,11 @@
     package_key
 } {
     return [db_string apm_package_installed_p {
-        select exists (select 1 from apm_package_versions
-                        where package_key = :package_key
-                          and installed_p) from dual
+        select case when exists
+        (select 1 from apm_package_versions
+         where package_key = :package_key
+         and installed_p) then 1 else 0 end
+        from dual
     }]
 }