fix-index-mutability-checks.patch

Index: src/backend/commands/indexcmds.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v
retrieving revision 1.195
diff -c -r1.195 indexcmds.c
*** src/backend/commands/indexcmds.c	22 Mar 2010 15:24:11 -0000	1.195
--- src/backend/commands/indexcmds.c	17 May 2010 19:50:54 -0000
***************
*** 35,40 ****
--- 35,41 ----
  #include "miscadmin.h"
  #include "nodes/nodeFuncs.h"
  #include "optimizer/clauses.h"
+ #include "optimizer/planner.h"
  #include "parser/parse_coerce.h"
  #include "parser/parse_func.h"
  #include "parser/parse_oper.h"
***************
*** 776,781 ****
--- 777,809 ----
  
  
  /*
+  * CheckMutability
+  *		Test whether given expression is mutable
+  */
+ static bool
+ CheckMutability(Expr *expr)
+ {
+ 	/*
+ 	 * First run the expression through the planner.  This has a couple of
+ 	 * important consequences.  First, function default arguments will get
+ 	 * inserted, which may affect volatility (consider "default now()").
+ 	 * Second, inline-able functions will get inlined, which may allow us to
+ 	 * conclude that the function is really less volatile than it's marked.
+ 	 * As an example, polymorphic functions must be marked with the most
+ 	 * volatile behavior that they have for any input type, but once we
+ 	 * inline the function we may be able to conclude that it's not so
+ 	 * volatile for the particular input type we're dealing with.
+ 	 *
+ 	 * We assume here that expression_planner() won't scribble on its input.
+ 	 */
+ 	expr = expression_planner(expr);
+ 
+ 	/* Now we can search for non-immutable functions */
+ 	return contain_mutable_functions((Node *) expr);
+ }
+ 
+ 
+ /*
   * CheckPredicate
   *		Checks that the given partial-index predicate is valid.
   *
***************
*** 806,812 ****
  	 * A predicate using mutable functions is probably wrong, for the same
  	 * reasons that we don't allow an index expression to use one.
  	 */
! 	if (contain_mutable_functions((Node *) predicate))
  		ereport(ERROR,
  				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
  		   errmsg("functions in index predicate must be marked IMMUTABLE")));
--- 834,840 ----
  	 * A predicate using mutable functions is probably wrong, for the same
  	 * reasons that we don't allow an index expression to use one.
  	 */
! 	if (CheckMutability(predicate))
  		ereport(ERROR,
  				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
  		   errmsg("functions in index predicate must be marked IMMUTABLE")));
***************
*** 922,928 ****
  			 * if you aren't going to get the same result for the same data
  			 * every time, it's not clear what the index entries mean at all.
  			 */
! 			if (contain_mutable_functions(attribute->expr))
  				ereport(ERROR,
  						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
  						 errmsg("functions in index expression must be marked IMMUTABLE")));
--- 950,956 ----
  			 * if you aren't going to get the same result for the same data
  			 * every time, it's not clear what the index entries mean at all.
  			 */
! 			if (CheckMutability((Expr *) attribute->expr))
  				ereport(ERROR,
  						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
  						 errmsg("functions in index expression must be marked IMMUTABLE")));