Fix division by zero in the new range type histogram creation.

Report and analysis by Matthias.

diff --git a/src/backend/utils/adt/rangetypes_typanalyze.c b/src/backend/utils/adt/rangetypes_typanalyze.c
index e276ad8e18125683c56ba0bd57ca88afd618fe57..5f346834e759c02713ba87675ff0203b6793e9f9 100644 (file)
--- a/src/backend/utils/adt/rangetypes_typanalyze.c
+++ b/src/backend/utils/adt/rangetypes_typanalyze.c
@@ -158,7 +158,10 @@ compute_range_stats(VacAttrStats *stats, AnalyzeAttrFetchFunc fetchfunc,
        /* Must copy the target values into anl_context */
        old_cxt = MemoryContextSwitchTo(stats->anl_context);
 
-       if (non_empty_cnt > 0)
+       /*
+        * Generate a histogram slot entry if there are at least two values.
+        */
+       if (non_empty_cnt >= 2)
        {
            /* Sort bound values */
            qsort_arg(lowers, non_empty_cnt, sizeof(RangeBound),