Fix ruleutils to produce correct output for array assignment, such

as UPDATE foo SET arr[3] = 42.

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 6d4da07207af6a09e00f36e9ccf93cd32c30792b..7d44657429d6910085f94866056b4c16f6e840c5 100644 (file)
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -3,7 +3,7 @@
  *                       out of its tuple
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.58 2000/08/08 15:42:21 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.59 2000/08/12 04:04:53 tgl Exp $
  *
  *       This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -107,6 +107,7 @@ static void get_func_expr(Expr *expr, deparse_context *context);
 static void get_tle_expr(TargetEntry *tle, deparse_context *context);
 static void get_const_expr(Const *constval, deparse_context *context);
 static void get_sublink_expr(Node *node, deparse_context *context);
+static bool tleIsArrayAssign(TargetEntry *tle);
 static char *quote_identifier(char *ident);
 static char *get_relation_name(Oid relid);
 static char *get_attribute_name(Oid relid, int2 attnum);
@@ -1186,8 +1187,14 @@ get_update_query_def(Query *query, deparse_context *context)
 
                appendStringInfo(buf, sep);
                sep = ", ";
-               appendStringInfo(buf, "%s = ",
-                                                quote_identifier(tle->resdom->resname));
+               /*
+                * If the update expression is an array assignment, we mustn't
+                * put out "attname =" here; it will come out of the display
+                * of the ArrayRef node instead.
+                */
+               if (! tleIsArrayAssign(tle))
+                       appendStringInfo(buf, "%s = ",
+                                                        quote_identifier(tle->resdom->resname));
                get_tle_expr(tle, context);
        }
 
@@ -1409,10 +1416,20 @@ get_rule_expr(Node *node, deparse_context *context)
                case T_ArrayRef:
                        {
                                ArrayRef   *aref = (ArrayRef *) node;
+                               bool            savevarprefix = context->varprefix;
                                List       *lowlist;
                                List       *uplist;
 
+                               /*
+                                * If we are doing UPDATE array[n] = expr, we need to
+                                * suppress any prefix on the array name.  Currently,
+                                * that is the only context in which we will see a non-null
+                                * refassgnexpr --- but someday a smarter test may be needed.
+                                */
+                               if (aref->refassgnexpr)
+                                       context->varprefix = false;
                                get_rule_expr(aref->refexpr, context);
+                               context->varprefix = savevarprefix;
                                lowlist = aref->reflowerindexpr;
                                foreach(uplist, aref->refupperindexpr)
                                {
@@ -1426,7 +1443,11 @@ get_rule_expr(Node *node, deparse_context *context)
                                        get_rule_expr((Node *) lfirst(uplist), context);
                                        appendStringInfo(buf, "]");
                                }
-                               /* XXX need to do anything with refassgnexpr? */
+                               if (aref->refassgnexpr)
+                               {
+                                       appendStringInfo(buf, " = ");
+                                       get_rule_expr(aref->refassgnexpr, context);
+                               }
                        }
                        break;
 
@@ -1842,6 +1863,31 @@ get_sublink_expr(Node *node, deparse_context *context)
                appendStringInfoChar(buf, ')');
 }
 
+/* ----------
+ * tleIsArrayAssign                    - check for array assignment
+ * ----------
+ */
+static bool
+tleIsArrayAssign(TargetEntry *tle)
+{
+       ArrayRef   *aref;
+
+       if (tle->expr == NULL || !IsA(tle->expr, ArrayRef))
+               return false;
+       aref = (ArrayRef *) tle->expr;
+       if (aref->refassgnexpr == NULL)
+               return false;
+       /*
+        * Currently, it should only be possible to see non-null refassgnexpr
+        * if we are indeed looking at an "UPDATE array[n] = expr" situation.
+        * So aref->refexpr ought to match the tle's target.
+        */
+       if (aref->refexpr == NULL || !IsA(aref->refexpr, Var) ||
+               ((Var *) aref->refexpr)->varno != tle->resdom->resno)
+               elog(NOTICE, "tleIsArrayAssign: I'm confused ...");
+       return true;
+}
+
 /* ----------
  * quote_identifier                    - Quote an identifier only if needed
  *