Fix const qualification in prune_freeze_setup()

The const qualification of the presult argument to prune_freeze_setup()
is later cast away, so it was not correct. Remove it and add a comment
explaining that presult should not be modified.

Author: Peter Eisentraut <[email protected]>
Reviewed-by: Melanie Plageman <[email protected]>
Discussion: https://postgr.es/m/fb97d0ae-a0bc-411d-8a87-f84e7e146488%40eisentraut.org

diff --git a/src/backend/access/heap/pruneheap.c b/src/backend/access/heap/pruneheap.c
index ca44225a10edde7986b0fd674f25f33f9eab3d3e..f99d92725b8841cb59549ceaabe6b0d310f3330a 100644 (file)
--- a/src/backend/access/heap/pruneheap.c
+++ b/src/backend/access/heap/pruneheap.c
@@ -160,7 +160,7 @@ typedef struct
 static void prune_freeze_setup(PruneFreezeParams *params,
                               TransactionId *new_relfrozen_xid,
                               MultiXactId *new_relmin_mxid,
-                              const PruneFreezeResult *presult,
+                              PruneFreezeResult *presult,
                               PruneState *prstate);
 static void prune_freeze_plan(Oid reloid, Buffer buffer,
                              PruneState *prstate,
@@ -322,12 +322,15 @@ heap_page_prune_opt(Relation relation, Buffer buffer)
 /*
  * Helper for heap_page_prune_and_freeze() to initialize the PruneState using
  * the provided parameters.
+ *
+ * params, new_relfrozen_xid, new_relmin_mxid, and presult are input
+ * parameters and are not modified by this function. Only prstate is modified.
  */
 static void
 prune_freeze_setup(PruneFreezeParams *params,
                   TransactionId *new_relfrozen_xid,
                   MultiXactId *new_relmin_mxid,
-                  const PruneFreezeResult *presult,
+                  PruneFreezeResult *presult,
                   PruneState *prstate)
 {
    /* Copy parameters to prstate */
@@ -382,7 +385,7 @@ prune_freeze_setup(PruneFreezeParams *params,
    prstate->recently_dead_tuples = 0;
    prstate->hastup = false;
    prstate->lpdead_items = 0;
-   prstate->deadoffsets = (OffsetNumber *) presult->deadoffsets;
+   prstate->deadoffsets = presult->deadoffsets;
    prstate->frz_conflict_horizon = InvalidTransactionId;
 
    /*