Fix tsquerysel() to not fail on an empty TSQuery. Per report from

Tatsuo Ishii.

diff --git a/src/backend/tsearch/ts_selfuncs.c b/src/backend/tsearch/ts_selfuncs.c
index 27cb30f77b75b58c4310fa3c1e1fdc370c97e705..890019c05897c5c212b10bac0a76a71b0c396580 100644 (file)
--- a/src/backend/tsearch/ts_selfuncs.c
+++ b/src/backend/tsearch/ts_selfuncs.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/tsearch/ts_selfuncs.c,v 1.2 2009/01/01 17:23:48 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/tsearch/ts_selfuncs.c,v 1.3 2009/06/03 18:42:13 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -146,19 +146,23 @@ static Selectivity
 tsquerysel(VariableStatData *vardata, Datum constval)
 {
        Selectivity                     selec;
+       TSQuery                         query;
+
+       /* The caller made sure the const is a TSQuery, so get it now */
+       query = DatumGetTSQuery(constval);
+
+       /* Empty query matches nothing */
+       if (query->size == 0)
+               return (Selectivity) 0.0;
 
        if (HeapTupleIsValid(vardata->statsTuple))
        {
-               TSQuery                         query;
                Form_pg_statistic       stats;
                Datum                           *values;
                int                                     nvalues;
                float4                          *numbers;
                int                                     nnumbers;
 
-               /* The caller made sure the const is a TSQuery, so get it now */
-               query = DatumGetTSQuery(constval);
-
                stats = (Form_pg_statistic) GETSTRUCT(vardata->statsTuple);
 
                /* MCELEM will be an array of TEXT elements for a tsvector column */