Index: openacs-4/packages/forums/tcl/forums-install-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/forums/tcl/forums-install-procs.tcl,v
diff -u -N -r1.10 -r1.10.2.1
--- openacs-4/packages/forums/tcl/forums-install-procs.tcl	7 Aug 2017 23:48:11 -0000	1.10
+++ openacs-4/packages/forums/tcl/forums-install-procs.tcl	7 May 2020 08:34:04 -0000	1.10.2.1
@@ -11,13 +11,19 @@
 ad_proc -private forum::install::package_install {} { 
     package install callback
 } {
-    forum::sc::register_implementations
+    # Since before 5.5, search is implemented using callbacks. New
+    # installations will not register search service contract
+    # implementations. See forums-callback-procs.
+    # forum::sc::register_implementations
 }
 
 ad_proc -private forum::install::package_uninstall {} { 
     package uninstall callback
 } {
-    forum::sc::unregister_implementations
+    # Since before 5.5, search is implemented using callbacks. New
+    # installations will not register search service contract
+    # implementations. See forums-callback-procs.
+    # forum::sc::unregister_implementations
 }
 
 ad_proc -private forum::install::package_upgrade {
@@ -34,6 +40,11 @@
                 # just need to install the forum_forum callback
                 forum::sc::register_forum_fts_impl
             }
+            1.3.1d17 1.3.1d18 {
+                # Unregister search service contract implementation
+                # and rely on callbacks from now on.
+                forum::sc::unregister_implementations
+            }
         }
 }