Index: openacs-4/packages/acs-api-browser/www/proc-view.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-api-browser/www/proc-view.tcl,v
diff -u -r1.16.2.3 -r1.16.2.4
--- openacs-4/packages/acs-api-browser/www/proc-view.tcl	30 Mar 2019 19:54:53 -0000	1.16.2.3
+++ openacs-4/packages/acs-api-browser/www/proc-view.tcl	1 Apr 2019 16:43:06 -0000	1.16.2.4
@@ -151,7 +151,7 @@
         set documentation [api_proc_documentation -script $proc_index]
     }
 }
-set procViewToggleURL [export_vars -base proc-view -no_empty {proc {source_p [expr {!$source_p}]} version_id}]
+set procViewToggleURL [export_vars -base proc-view -no_empty {proc {source_p "[expr {!$source_p}]"} version_id}]
 set setDefaultURL     [export_vars -base set-default {source_p return_url}]
 
 #