Change SET LOCAL/CONSTRAINTS/TRANSACTION and ABORT behavior

Change SET LOCAL/CONSTRAINTS/TRANSACTION behavior outside of a
transaction block from error (post-9.3) to warning.  (Was nothing in <=
9.3.)  Also change ABORT outside of a transaction block from notice to
warning.

1 files changed, 30 insertions, 7 deletions

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 0591f3fd562..bab048d38a1 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -265,6 +265,8 @@ static void CallSubXactCallbacks(SubXactEvent event,
 					 SubTransactionId mySubid,
 					 SubTransactionId parentSubid);
 static void CleanupTransaction(void);
+static void CheckTransactionChain(bool isTopLevel, bool throwError,
+					 const char *stmtType);
 static void CommitTransaction(void);
 static TransactionId RecordTransactionAbort(bool isSubXact);
 static void StartTransaction(void);
@@ -2949,6 +2951,26 @@ PreventTransactionChain(bool isTopLevel, const char *stmtType)
 }
 
 /*
+ *	These two functions allow for warnings or errors if a command is
+ *	executed outside of a transaction block.
+ *
+ *	While top-level transaction control commands (BEGIN/COMMIT/ABORT) and
+ *	SET that have no effect issue warnings, all other no-effect commands
+ *	generate errors.
+ */
+void
+WarnNoTransactionChain(bool isTopLevel, const char *stmtType)
+{
+	CheckTransactionChain(isTopLevel, false, stmtType);
+}
+
+void
+RequireTransactionChain(bool isTopLevel, const char *stmtType)
+{
+	CheckTransactionChain(isTopLevel, true, stmtType);
+}
+
+/*
  *	RequireTransactionChain
  *
  *	This routine is to be called by statements that must run inside
@@ -2957,16 +2979,16 @@ PreventTransactionChain(bool isTopLevel, const char *stmtType)
  *	is presumably an error).  DECLARE CURSOR is an example.
  *
  *	If we appear to be running inside a user-defined function, we do not
- *	issue an error, since the function could issue more commands that make
+ *	issue anything, since the function could issue more commands that make
  *	use of the current statement's results.  Likewise subtransactions.
  *	Thus this is an inverse for PreventTransactionChain.
  *
  *	isTopLevel: passed down from ProcessUtility to determine whether we are
  *	inside a function.
- *	stmtType: statement type name, for error messages.
+ *	stmtType: statement type name, for warning or error messages.
  */
-void
-RequireTransactionChain(bool isTopLevel, const char *stmtType)
+static void
+CheckTransactionChain(bool isTopLevel, bool throwError, const char *stmtType)
 {
 	/*
 	 * xact block already started?
@@ -2986,11 +3008,12 @@ RequireTransactionChain(bool isTopLevel, const char *stmtType)
 	if (!isTopLevel)
 		return;
 
-	ereport(ERROR,
+	ereport(throwError ? ERROR : WARNING,
 			(errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
 	/* translator: %s represents an SQL statement name */
 			 errmsg("%s can only be used in transaction blocks",
 					stmtType)));
+	return;
 }
 
 /*
@@ -3425,12 +3448,12 @@ UserAbortTransactionBlock(void)
 
 			/*
 			 * The user issued ABORT when not inside a transaction. Issue a
-			 * NOTICE and go to abort state.  The upcoming call to
+			 * WARNING and go to abort state.  The upcoming call to
 			 * CommitTransactionCommand() will then put us back into the
 			 * default state.
 			 */
 		case TBLOCK_STARTED:
-			ereport(NOTICE,
+			ereport(WARNING,
 					(errcode(ERRCODE_NO_ACTIVE_SQL_TRANSACTION),
 					 errmsg("there is no transaction in progress")));
 			s->blockState = TBLOCK_ABORT_PENDING;