Add explicit cast to amcostestimate call.

My compiler doesn't complain here, but David Rowley's does ...

diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 8fb483aaebd96618d421e510bea1d5ef67ed2602..eaeb17fcd4158facd283aa7ac38e55df066c52a4 100644 (file)
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -419,9 +419,10 @@ cost_index(IndexPath *path, PlannerInfo *root, double loop_count)
         * Call index-access-method-specific code to estimate the processing cost
         * for scanning the index, as well as the selectivity of the index (ie,
         * the fraction of main-table tuples we will have to retrieve) and its
-        * correlation to the main-table tuple order.
+        * correlation to the main-table tuple order.  We need a cast here because
+        * relation.h uses a weak function type to avoid including amapi.h.
         */
-       amcostestimate = index->amcostestimate;         /* cast to proper type */
+       amcostestimate = (amcostestimate_function) index->amcostestimate;
        amcostestimate(root, path, loop_count,
                                   &indexStartupCost, &indexTotalCost,
                                   &indexSelectivity, &indexCorrelation);