Fix misuse of TextDatumGetCString().

tglsfdc · tglsfdc · commit ac50f84866b2 · 2015-07-02T17:02:08.000-04:00
"TextDatumGetCString(PG_GETARG_TEXT_P(x))" is formally wrong: a text*
is not a Datum.  Although this coding will accidentally fail to fail on
all known platforms, it risks leaking memory if a detoast step is needed,
unlike "TextDatumGetCString(PG_GETARG_DATUM(x))" which is what's used
elsewhere.  Make pg_get_object_address() fall in line with other uses.

Noted while reviewing two-arg current_setting() patch.
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
@@ -1831,7 +1831,7 @@ textarray_to_strvaluelist(ArrayType *arr)
 Datum
 pg_get_object_address(PG_FUNCTION_ARGS)
 {
-	char	   *ttype = TextDatumGetCString(PG_GETARG_TEXT_P(0));
+	char	   *ttype = TextDatumGetCString(PG_GETARG_DATUM(0));
 	ArrayType  *namearr = PG_GETARG_ARRAYTYPE_P(1);
 	ArrayType  *argsarr = PG_GETARG_ARRAYTYPE_P(2);
 	int			itype;

Original file line number	Diff line number	Diff line change
`@@ -1831,7 +1831,7 @@ textarray_to_strvaluelist(ArrayType *arr)`
`1831`	`1831`	`Datum`
`1832`	`1832`	`pg_get_object_address(PG_FUNCTION_ARGS)`
`1833`	`1833`	`{`
`1834`		`- char *ttype = TextDatumGetCString(PG_GETARG_TEXT_P(0));`
	`1834`	`+ char *ttype = TextDatumGetCString(PG_GETARG_DATUM(0));`
`1835`	`1835`	`ArrayType *namearr = PG_GETARG_ARRAYTYPE_P(1);`
`1836`	`1836`	`ArrayType *argsarr = PG_GETARG_ARRAYTYPE_P(2);`
`1837`	`1837`	`int itype;`