Index: openacs-4/packages/tsearch2-driver/tcl/tsearch2-driver-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/tsearch2-driver/tcl/tsearch2-driver-procs.tcl,v
diff -u -r1.33 -r1.34
--- openacs-4/packages/tsearch2-driver/tcl/tsearch2-driver-procs.tcl	7 Aug 2017 23:48:29 -0000	1.33
+++ openacs-4/packages/tsearch2-driver/tcl/tsearch2-driver-procs.tcl	28 Feb 2018 08:35:16 -0000	1.34
@@ -9,6 +9,29 @@
 
 namespace eval tsearch2 {}
 
+ad_proc -private tsearch2::trunc_to_max {txt} {
+    
+    tsearch has (at least up to PostgreSQL 10) the limitation that
+    the length of tsvector is 1MB. so make sure, we do not raise
+    errors, when this happens.
+    
+    https://www.postgresql.org/docs/current/static/textsearch-limitations.html
+} {
+    set max_size_to_index [db_string get_max_size_to_index {
+	select min(default_value) from apm_parameters
+	where package_key = 'tsearch2-driver' and
+	parameter_name = 'max_size_to_index'
+    } -default "1048575"]
+    if {$max_size_to_index == 0} {
+	set max_size_to_index 1048575
+    }
+    if {$max_size_to_index > 0 && [string length $txt] > $max_size_to_index} {
+	ns_log notice "tsearch2: truncate overlong string to $max_size_to_index bytes"
+        set txt [string range $txt 0 $max_size_to_index-1]
+    }
+    return $txt
+}
+
 ad_proc -public tsearch2::index {
     object_id
     txt
@@ -29,11 +52,8 @@
 } {
     set index_exists_p [db_0or1row object_exists "select 1 from txt where object_id=:object_id"]
     if {!$index_exists_p} {
-      set max_size_to_index [db_string get_max_size_to_index "select min(default_value) from apm_parameters where package_key = 'tsearch2-driver' and parameter_name = 'max_size_to_index'" -default "0"]
-      if {$max_size_to_index > 0} {
-        set txt [string range $txt 0 $max_size_to_index]
-      }
-      db_dml index {}
+	set txt [tsearch2::trunc_to_max $txt]
+	db_dml index {}
     } else {
         tsearch2::update_index $object_id $txt $title $keywords
     }
@@ -76,10 +96,7 @@
     if {!$index_exists_p} {
         tsearch2::index $object_id $txt $title $keywords
     } else {
-      set max_size_to_index [db_string get_max_size_to_index "select min(default_value) from apm_parameters where package_key = 'tsearch2-driver' and parameter_name = 'max_size_to_index'" -default "0"]
-      if {$max_size_to_index > 0} {
-        set txt [string range $txt 0 $max_size_to_index]
-      }
+	set txt [tsearch2::trunc_to_max $txt]
         db_dml update_index ""
     }
 }