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Fix broken list-slinging logic in func_select_candidate and

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agg_select_candidate, which could cause them to keep more candidates
than they should and thus fail to select a single match.  I had
previously fixed the identical bug in oper_select_candidate, but
didn't realize that the same error was repeated over here.
Also, repair func_select_candidate's curious notion that it could
scribble on the input type-OID vector.  That was causing failure to
apply necessary type coercion later on, leading to malfunction of
examples such as select date('now').
This commit is contained in:
Tom Lane 2000-02-20 06:35:08 +00:00
parent f4d108a257
commit 5253c518ae
1 changed files with 42 additions and 24 deletions
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50
src/backend/parser/parse_func.c
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@ -8,7 +8,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.69 2000/02/15 03:37:47 thomas Exp $ * $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.70 2000/02/20 06:35:08 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -45,8 +45,7 @@ static Oid **argtype_inherit(int nargs, Oid *oid_array);
static int find_inheritors(Oid relid, Oid **supervec); static int find_inheritors(Oid relid, Oid **supervec);
static CandidateList func_get_candidates(char *funcname, int nargs); static CandidateList func_get_candidates(char *funcname, int nargs);
static bool static bool func_get_detail(char *funcname,
func_get_detail(char *funcname,
int nargs, int nargs,
Oid *oid_array, Oid *oid_array,
Oid *funcid, /* return value */ Oid *funcid, /* return value */
@ -228,10 +227,11 @@ agg_select_candidate(Oid typeid, CandidateList candidates)
} }
} }
/* otherwise, don't bother keeping this one around... */ /* otherwise, don't bother keeping this one around... */
else if (last_candidate != NULL)
last_candidate->next = NULL;
} }
if (last_candidate) /* terminate rebuilt list */
last_candidate->next = NULL;
return ((ncandidates == 1) ? candidates->args[0] : 0); return ((ncandidates == 1) ? candidates->args[0] : 0);
} /* agg_select_candidate() */ } /* agg_select_candidate() */
@ -559,8 +559,8 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
} }
/* Most of the rest of the parser just assumes that functions do not /* Most of the rest of the parser just assumes that functions do not
* have more than FUNC_MAX_ARGS parameters. We have to test here to protect * have more than FUNC_MAX_ARGS parameters. We have to test here
* against array overruns, etc. * to protect against array overruns, etc.
*/ */
if (nargs >= FUNC_MAX_ARGS) if (nargs >= FUNC_MAX_ARGS)
elog(ERROR, "Cannot pass more than %d arguments to a function", elog(ERROR, "Cannot pass more than %d arguments to a function",
@ -892,6 +892,7 @@ func_select_candidate(int nargs,
if ((nmatch + nident) == nargs) if ((nmatch + nident) == nargs)
return current_candidate->args; return current_candidate->args;
/* take this one as the best choice so far? */
if ((nmatch > nbestMatch) || (last_candidate == NULL)) if ((nmatch > nbestMatch) || (last_candidate == NULL))
{ {
nbestMatch = nmatch; nbestMatch = nmatch;
@ -899,16 +900,19 @@ func_select_candidate(int nargs,
last_candidate = current_candidate; last_candidate = current_candidate;
ncandidates = 1; ncandidates = 1;
} }
/* no worse than the last choice, so keep this one too? */
else if (nmatch == nbestMatch) else if (nmatch == nbestMatch)
{ {
last_candidate->next = current_candidate; last_candidate->next = current_candidate;
last_candidate = current_candidate; last_candidate = current_candidate;
ncandidates++; ncandidates++;
} }
else /* otherwise, don't bother keeping this one... */
last_candidate->next = NULL;
} }
if (last_candidate) /* terminate rebuilt list */
last_candidate->next = NULL;
if (ncandidates == 1) if (ncandidates == 1)
return candidates->args; return candidates->args;
@ -922,6 +926,7 @@ func_select_candidate(int nargs,
{ {
slot_category = INVALID_TYPE; slot_category = INVALID_TYPE;
slot_type = InvalidOid; slot_type = InvalidOid;
last_candidate = NULL;
for (current_candidate = candidates; for (current_candidate = candidates;
current_candidate != NULL; current_candidate != NULL;
current_candidate = current_candidate->next) current_candidate = current_candidate->next)
@ -935,26 +940,39 @@ func_select_candidate(int nargs,
slot_category = current_category; slot_category = current_category;
slot_type = current_type; slot_type = current_type;
} }
else if ((current_category != slot_category) else if (current_category != slot_category)
&& IS_BUILTIN_TYPE(current_type)) {
/* punt if more than one category for this slot */
return NULL; return NULL;
}
else if (current_type != slot_type) else if (current_type != slot_type)
{ {
if (IsPreferredType(slot_category, current_type)) if (IsPreferredType(slot_category, current_type))
{ {
slot_type = current_type; slot_type = current_type;
/* forget all previous candidates */
candidates = current_candidate; candidates = current_candidate;
last_candidate = current_candidate;
} }
else if (IsPreferredType(slot_category, slot_type)) else if (IsPreferredType(slot_category, slot_type))
candidates->next = current_candidate->next; {
/* forget this candidate */
if (last_candidate)
last_candidate->next = current_candidate->next;
else
candidates = current_candidate->next;
} }
} else
last_candidate = current_candidate;
if (slot_type != InvalidOid)
input_typeids[i] = slot_type;
} }
else else
{ {
/* keep this candidate */
last_candidate = current_candidate;
}
}
if (last_candidate) /* terminate rebuilt list */
last_candidate->next = NULL;
} }
} }