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),