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Turns out that Mazurkiewicz's gripe about 'function inheritance' is
actually a type-coercion problem. If you have a function defined on class A, and class B inherits from A, then the function ought to work on class B as well --- but coerce_type didn't know that. Now it does.
This commit is contained in:
Tom Lane
parent
d4a2c86eaf
commit
d14c8aab99
@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/parser/parse_coerce.c,v 2.35 2000/03/14 23:06:32 thomas Exp $
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* $Header: /cvsroot/pgsql/src/backend/parser/parse_coerce.c,v 2.36 2000/03/16 06:35:07 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -103,6 +103,11 @@ coerce_type(ParseState *pstate, Node *node, Oid inputTypeId,
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result = (Node *) relabel;
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}
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else if (typeInheritsFrom(inputTypeId, targetTypeId))
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{
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/* Input class type is a subclass of target, so nothing to do */
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result = node;
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}
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else
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{
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/*
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@ -156,62 +161,69 @@ coerce_type(ParseState *pstate, Node *node, Oid inputTypeId,
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bool
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can_coerce_type(int nargs, Oid *input_typeids, Oid *func_typeids)
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{
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HeapTuple ftup;
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int i;
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Type tp;
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HeapTuple ftup;
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Oid oid_array[FUNC_MAX_ARGS];
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/* run through argument list... */
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for (i = 0; i < nargs; i++)
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{
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if (input_typeids[i] != func_typeids[i])
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{
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Oid inputTypeId = input_typeids[i];
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Oid targetTypeId = func_typeids[i];
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/* no problem if same type */
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if (inputTypeId == targetTypeId)
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continue;
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/*
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* one of the known-good transparent conversions? then drop
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* through...
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*/
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if (IS_BINARY_COMPATIBLE(input_typeids[i], func_typeids[i]))
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;
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if (IS_BINARY_COMPATIBLE(inputTypeId, targetTypeId))
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continue;
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/* don't know what to do for the output type? then quit... */
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else if (func_typeids[i] == InvalidOid)
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if (targetTypeId == InvalidOid)
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return false;
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/* don't know what to do for the input type? then quit... */
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else if (input_typeids[i] == InvalidOid)
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if (inputTypeId == InvalidOid)
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return false;
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/*
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* if not unknown input type, try for explicit conversion
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* using functions...
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* If input is an untyped string constant, assume we can
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* convert it to anything except a class type.
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*/
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else if (input_typeids[i] != UNKNOWNOID)
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if (inputTypeId == UNKNOWNOID)
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{
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MemSet(oid_array, 0, FUNC_MAX_ARGS * sizeof(Oid));
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oid_array[0] = input_typeids[i];
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if (ISCOMPLEX(targetTypeId))
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return false;
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continue;
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}
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/*
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* look for a single-argument function named with the
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* target type name
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* If input is a class type that inherits from target, no problem
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*/
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if (typeInheritsFrom(inputTypeId, targetTypeId))
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continue;
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/*
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* Else, try for explicit conversion using functions:
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* look for a single-argument function named with the
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* target type name and accepting the source type.
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*/
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MemSet(oid_array, 0, FUNC_MAX_ARGS * sizeof(Oid));
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oid_array[0] = inputTypeId;
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ftup = SearchSysCacheTuple(PROCNAME,
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PointerGetDatum(typeidTypeName(func_typeids[i])),
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PointerGetDatum(typeidTypeName(targetTypeId)),
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Int32GetDatum(1),
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PointerGetDatum(oid_array),
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0);
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/*
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* should also check the function return type just to be
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* safe...
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*/
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if (!HeapTupleIsValid(ftup))
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return false;
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}
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tp = typeidType(input_typeids[i]);
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if (typeTypeFlag(tp) == 'c')
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return false;
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}
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/*
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* should also check the function return type just to be safe...
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*/
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}
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return true;
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@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.74 2000/03/14 23:06:32 thomas Exp $
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* $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.75 2000/03/16 06:35:07 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -68,7 +68,6 @@ static Oid *func_select_candidate(int nargs, Oid *input_typeids,
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static int agg_get_candidates(char *aggname, Oid typeId, CandidateList *candidates);
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static Oid agg_select_candidate(Oid typeid, CandidateList candidates);
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#define ISCOMPLEX(type) (typeidTypeRelid(type) ? true : false)
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/*
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** ParseNestedFuncOrColumn
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@ -1360,6 +1359,40 @@ gen_cross_product(InhPaths *arginh, int nargs)
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}
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/*
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* Given two type OIDs, determine whether the first is a complex type
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* (class type) that inherits from the second.
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*/
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bool
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typeInheritsFrom(Oid subclassTypeId, Oid superclassTypeId)
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{
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Oid relid;
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Oid *supervec;
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int nsupers,
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i;
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bool result;
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if (!ISCOMPLEX(subclassTypeId) || !ISCOMPLEX(superclassTypeId))
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return false;
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relid = typeidTypeRelid(subclassTypeId);
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if (relid == InvalidOid)
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return false;
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nsupers = find_inheritors(relid, &supervec);
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result = false;
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for (i = 0; i < nsupers; i++)
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{
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if (supervec[i] == superclassTypeId)
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{
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result = true;
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break;
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}
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}
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if (supervec)
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pfree(supervec);
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return result;
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}
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/* make_arguments()
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* Given the number and types of arguments to a function, and the
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* actual arguments and argument types, do the necessary typecasting.
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@ -7,7 +7,7 @@
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* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: parse_func.h,v 1.22 2000/01/26 05:58:27 momjian Exp $
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* $Id: parse_func.h,v 1.23 2000/03/16 06:35:06 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -47,6 +47,8 @@ extern Node *ParseFuncOrColumn(ParseState *pstate,
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extern List *setup_base_tlist(Oid typeid);
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extern bool typeInheritsFrom(Oid subclassTypeId, Oid superclassTypeId);
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extern void func_error(char *caller, char *funcname,
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int nargs, Oid *argtypes, char *msg);
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@ -7,7 +7,7 @@
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* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $Id: parse_type.h,v 1.12 2000/01/26 05:58:27 momjian Exp $
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* $Id: parse_type.h,v 1.13 2000/03/16 06:35:06 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -35,4 +35,6 @@ extern Oid GetArrayElementType(Oid typearray);
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extern Oid typeInfunc(Type typ);
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extern Oid typeOutfunc(Type typ);
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#define ISCOMPLEX(typeid) (typeidTypeRelid(typeid) != InvalidOid)
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#endif /* PARSE_TYPE_H */
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