Index: src/include/access/xact.h
===================================================================
RCS file: /home/ncvs/pgsql/pgsql-server/src/include/access/xact.h,v
retrieving revision 1.52
diff -u -r1.52 xact.h
--- src/include/access/xact.h	14 May 2003 03:26:03 -0000	1.52
+++ src/include/access/xact.h	30 Jul 2003 21:27:04 -0000
@@ -33,6 +33,7 @@
 /* Xact read-only state */
 extern bool	DefaultXactReadOnly;
 extern bool	XactReadOnly;
+extern bool	JailReadOnlyXacts;
 
 /*
  *	transaction states - transaction state from server perspective
Index: src/backend/utils/misc/guc.c
===================================================================
RCS file: /home/ncvs/pgsql/pgsql-server/src/backend/utils/misc/guc.c,v
retrieving revision 1.144
diff -u -r1.144 guc.c
--- src/backend/utils/misc/guc.c	29 Jul 2003 00:03:18 -0000	1.144
+++ src/backend/utils/misc/guc.c	30 Jul 2003 21:30:50 -0000
@@ -94,6 +94,7 @@
 static const char *assign_log_error_verbosity(const char *newval, bool doit,
 						   bool interactive);
 static bool assign_phony_autocommit(bool newval, bool doit, bool interactive);
+static bool assign_transaction_read_only(bool newval, bool doit, bool interactive);
 
 
 /*
@@ -814,6 +815,15 @@
 			GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 		},
 		&XactReadOnly,
+		false, assign_transaction_read_only, NULL
+	},
+	{
+		{"jail_read_only_transactions", PGC_SUSET, CLIENT_CONN_STATEMENT,
+			gettext_noop("Jails transactions that are READ ONLY so that users can't change the transaction from being in a READ ONLY mode"),
+			NULL,
+			GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE
+		},
+		&JailReadOnlyXacts,
 		false, NULL, NULL
 	},
 	{
@@ -4375,6 +4385,39 @@
 		return false;
 	}
 	return true;
+}
+
+
+static bool
+assign_transaction_read_only(bool newval, bool doit, bool interactive)
+{
+	if (JailReadOnlyXacts == false)
+	{
+		if (doit == true)
+			XactReadOnly = newval;
+		return true;
+	} else {
+		if (superuser() == false)
+		{
+			if (newval == true)
+			{
+				if (doit)
+					XactReadOnly = true;
+
+				return true;
+			} else {
+				if (doit && interactive)
+					ereport(ERROR,
+						(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+						 errmsg("Insufficient privileges to SET transaction_read_only TO FALSE")));
+				return false;
+			}
+		} else {
+			if (doit)
+				XactReadOnly = newval;
+			return true;
+		}
+	}
 }
 
 
Index: src/backend/access/transam/xact.c
===================================================================
RCS file: /home/ncvs/pgsql/pgsql-server/src/backend/access/transam/xact.c,v
retrieving revision 1.149
diff -u -r1.149 xact.c
--- src/backend/access/transam/xact.c	21 Jul 2003 20:29:39 -0000	1.149
+++ src/backend/access/transam/xact.c	30 Jul 2003 21:31:17 -0000
@@ -211,6 +211,7 @@
 
 bool		DefaultXactReadOnly = false;
 bool		XactReadOnly;
+bool		JailReadOnlyXacts = false;
 
 int			CommitDelay = 0;	/* precommit delay in microseconds */
 int			CommitSiblings = 5; /* number of concurrent xacts needed to