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 */