Fix failure-to-copy bug in commit 6f6b99d13.

The previous coding of get_qual_for_list() was careful to copy everything
it was using from the input data structure.  The new version missed
making a copy of pass-by-ref datum values that it's inserting into Consts.
This is not optional, however, as revealed by buildfarm failures on
machines running -DRELCACHE_FORCE_RELEASE: we're copying from a relcache
entry that could go away before the required lifespan of our output
expression.  I'm pretty sure -DCLOBBER_CACHE_ALWAYS machines won't like
this either, but none of them have reported in yet.

diff --git a/src/backend/catalog/partition.c b/src/backend/catalog/partition.c
index c94ee941ded1d5e863b744874ad183ccd175e993..73eff17202c90f1d546228dbc61be7d6279026a7 100644 (file)
--- a/src/backend/catalog/partition.c
+++ b/src/backend/catalog/partition.c
@@ -1559,12 +1559,18 @@ get_qual_for_list(Relation parent, PartitionBoundSpec *spec)
        {
            Const      *val;
 
-           /* Construct const from datum */
+           /*
+            * Construct Const from known-not-null datum.  We must be careful
+            * to copy the value, because our result has to be able to outlive
+            * the relcache entry we're copying from.
+            */
            val = makeConst(key->parttypid[0],
                            key->parttypmod[0],
                            key->parttypcoll[0],
                            key->parttyplen[0],
-                           *boundinfo->datums[i],
+                           datumCopy(*boundinfo->datums[i],
+                                     key->parttypbyval[0],
+                                     key->parttyplen[0]),
                            false,  /* isnull */
                            key->parttypbyval[0]);