Pass collations to functions in FunctionCallInfoData, not FmgrInfo.

Since collation is effectively an argument, not a property of the function,
FmgrInfo is really the wrong place for it; and this becomes critical in
cases where a cached FmgrInfo is used for varying purposes that might need
different collation settings.  Fix by passing it in FunctionCallInfoData
instead.  In particular this allows a clean fix for bug #5970 (record_cmp
not working).  This requires touching a bit more code than the original
method, but nobody ever thought that collations would not be an invasive
patch...

3 files changed, 14 insertions, 7 deletions

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index dde301b89aa..0568a1bcf86 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -1930,8 +1930,6 @@ compute_minimal_stats(VacAttrStatsP stats,
 	track_cnt = 0;
 
 	fmgr_info(mystats->eqfunc, &f_cmpeq);
-	/* We always use the default collation for statistics */
-	fmgr_info_set_collation(DEFAULT_COLLATION_OID, &f_cmpeq);
 
 	for (i = 0; i < samplerows; i++)
 	{
@@ -1990,7 +1988,10 @@ compute_minimal_stats(VacAttrStatsP stats,
 		firstcount1 = track_cnt;
 		for (j = 0; j < track_cnt; j++)
 		{
-			if (DatumGetBool(FunctionCall2(&f_cmpeq, value, track[j].value)))
+			/* We always use the default collation for statistics */
+			if (DatumGetBool(FunctionCall2Coll(&f_cmpeq,
+											   DEFAULT_COLLATION_OID,
+											   value, track[j].value)))
 			{
 				match = true;
 				break;
@@ -2253,8 +2254,6 @@ compute_scalar_stats(VacAttrStatsP stats,
 
 	SelectSortFunction(mystats->ltopr, false, &cmpFn, &cmpFlags);
 	fmgr_info(cmpFn, &f_cmpfn);
-	/* We always use the default collation for statistics */
-	fmgr_info_set_collation(DEFAULT_COLLATION_OID, &f_cmpfn);
 
 	/* Initial scan to find sortable values */
 	for (i = 0; i < samplerows; i++)
@@ -2729,7 +2728,9 @@ compare_scalars(const void *a, const void *b, void *arg)
 	CompareScalarsContext *cxt = (CompareScalarsContext *) arg;
 	int32		compare;
 
+	/* We always use the default collation for statistics */
 	compare = ApplySortFunction(cxt->cmpFn, cxt->cmpFlags,
+								DEFAULT_COLLATION_OID,
 								da, false, db, false);
 	if (compare != 0)
 		return compare;
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 6b1ade89903..ce36ea8be45 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -1822,7 +1822,8 @@ ExecCallTriggerFunc(TriggerData *trigdata,
 	/*
 	 * Call the function, passing no arguments but setting a context.
 	 */
-	InitFunctionCallInfoData(fcinfo, finfo, 0, (Node *) trigdata, NULL);
+	InitFunctionCallInfoData(fcinfo, finfo, 0,
+							 InvalidOid, (Node *) trigdata, NULL);
 
 	pgstat_init_function_usage(&fcinfo, &fcusage);
 
diff --git a/src/backend/commands/tsearchcmds.c b/src/backend/commands/tsearchcmds.c
index ce0086ffa17..d08c9bbbc5c 100644
--- a/src/backend/commands/tsearchcmds.c
+++ b/src/backend/commands/tsearchcmds.c
@@ -96,6 +96,11 @@ get_ts_parser_func(DefElem *defel, int attnum)
 			break;
 		case Anum_pg_ts_parser_prslextype:
 			nargs = 1;
+			/*
+			 * Note: because the lextype method returns type internal, it must
+			 * have an internal-type argument for security reasons.  The
+			 * argument is not actually used, but is just passed as a zero.
+			 */
 			break;
 		default:
 			/* should not be here */
@@ -1947,7 +1952,7 @@ getTokenTypes(Oid prsId, List *tokennames)
 		elog(ERROR, "method lextype isn't defined for text search parser %u",
 			 prsId);
 
-	/* OidFunctionCall0 is absent */
+	/* lextype takes one dummy argument */
 	list = (LexDescr *) DatumGetPointer(OidFunctionCall1(prs->lextypeOid,
 														 (Datum) 0));