postgres.git / summary / log / commit / refs

commit    060b22a99a67e01aa097f1a21d2123f166ccdb15
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Fri Nov 08 13:59:39 2013 +0000

    Fix subtly-wrong volatility checking in BeginCopyFrom().
    
    contain_volatile_functions() is best applied to the output of
    expression_planner(), not its input, so that insertion of function
    default arguments and constant-folding have been done.  (See comments
    at CheckMutability, for instance.)  It's perhaps unlikely that anyone
    will notice a difference in practice, but still we should do it properly.
    
    In passing, change variable type from Node* to Expr* to reduce the net
    number of casts needed.
    
    Noted while perusing uses of contain_volatile_functions().


 src/backend/commands/copy.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 6b20144a48c..0fa83a6e2fd 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -2506,18 +2506,22 @@ BeginCopyFrom(Relation rel,
 		{
 			/* attribute is NOT to be copied from input */
 			/* use default value if one exists */
-			Node	   *defexpr = build_column_default(cstate->rel, attnum);
+			Expr	   *defexpr = (Expr *) build_column_default(cstate->rel,
+																attnum);
 
 			if (defexpr != NULL)
 			{
-				/* Initialize expressions in copycontext. */
-				defexprs[num_defaults] = ExecInitExpr(
-								 expression_planner((Expr *) defexpr), NULL);
+				/* Run the expression through planner */
+				defexpr = expression_planner(defexpr);
+
+				/* Initialize executable expression in copycontext */
+				defexprs[num_defaults] = ExecInitExpr(defexpr, NULL);
 				defmap[num_defaults] = attnum - 1;
 				num_defaults++;
 
+				/* Check to see if we have any volatile expressions */
 				if (!volatile_defexprs)
-					volatile_defexprs = contain_volatile_functions(defexpr);
+					volatile_defexprs = contain_volatile_functions((Node *) defexpr);
 			}
 		}
 	}


[parent: 20803d7881c3]