Fix thinkos in LookupFuncName() for function name lookups

michaelpq · michaelpq · commit 131e545ac304 · 2019-06-25T11:16:04.000+09:00
This could trigger valgrind failures when doing ambiguous function name lookups when no arguments are provided by the caller. The problem has been introduced in aefeb68, so backpatch to v10. HEAD is fine thanks to the refactoring done in bfb456c. Reported-by: Alexander Lakhin Author: Alexander Lakhin, Michael Paquier Discussion: https://postgr.es/m/3d068be5-f617-a5ee-99f6-458a407bfd65@gmail.com Backpatch-through: 10
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
@@ -1950,9 +1950,10 @@ LookupFuncName(List *funcname, int nargs, const Oid *argtypes, bool noError)
 							 errmsg("function name \"%s\" is not unique",
 									NameListToString(funcname)),
 							 errhint("Specify the argument list to select the function unambiguously.")));
+				return InvalidOid;
 			}
-			else
-				return clist->oid;
+			/* Otherwise return the match */
+			return clist->oid;
 		}
 		else
 		{
@@ -1961,9 +1962,14 @@ LookupFuncName(List *funcname, int nargs, const Oid *argtypes, bool noError)
 						(errcode(ERRCODE_UNDEFINED_FUNCTION),
 						 errmsg("could not find a function named \"%s\"",
 								NameListToString(funcname))));
+			return InvalidOid;
 		}
 	}
 
+	/*
+	 * Otherwise, look for a match to the arg types.  FuncnameGetCandidates
+	 * has ensured that there's at most one match in the returned list.
+	 */
 	while (clist)
 	{
 		if (memcmp(argtypes, clist->args, nargs * sizeof(Oid)) == 0)

Original file line number	Diff line number	Diff line change
`@@ -1950,9 +1950,10 @@ LookupFuncName(List funcname, int nargs, const Oid argtypes, bool noError)`
`1950`	`1950`	`errmsg("function name \"%s\" is not unique",`
`1951`	`1951`	`NameListToString(funcname)),`
`1952`	`1952`	`errhint("Specify the argument list to select the function unambiguously.")));`
	`1953`	`+ return InvalidOid;`
`1953`	`1954`	`}`
`1954`		`- else`
`1955`		`- return clist->oid;`
	`1955`	`+ /* Otherwise return the match */`
	`1956`	`+ return clist->oid;`
`1956`	`1957`	`}`
`1957`	`1958`	`else`
`1958`	`1959`	`{`
`@@ -1961,9 +1962,14 @@ LookupFuncName(List funcname, int nargs, const Oid argtypes, bool noError)`
`1961`	`1962`	`(errcode(ERRCODE_UNDEFINED_FUNCTION),`
`1962`	`1963`	`errmsg("could not find a function named \"%s\"",`
`1963`	`1964`	`NameListToString(funcname))));`
	`1965`	`+ return InvalidOid;`
`1964`	`1966`	`}`
`1965`	`1967`	`}`
`1966`	`1968`
	`1969`	`+ /*`
	`1970`	`+ * Otherwise, look for a match to the arg types. FuncnameGetCandidates`
	`1971`	`+ * has ensured that there's at most one match in the returned list.`
	`1972`	`+ */`
`1967`	`1973`	`while (clist)`
`1968`	`1974`	`{`
`1969`	`1975`	`if (memcmp(argtypes, clist->args, nargs * sizeof(Oid)) == 0)`