The list comp patch checked for the second child node of the 'listmaker'

Yhg1s · Yhg1s · commit 87df80d542b5 · 2000-08-13T17:05:17.000Z
node, without checking if the node actually had more than one child. It can
have only one node, though: '[' test ']'. This fixes it.
diff --git a/Python/compile.c b/Python/compile.c
@@ -1045,7 +1045,7 @@ static void
 com_listmaker(struct compiling *c, node *n)
 {
 	/* listmaker: test ( list_iter | (',' test)* [','] ) */
-	if (TYPE(CHILD(n, 1)) == list_iter)
+	if (NCH(n) > 1 && TYPE(CHILD(n, 1)) == list_iter)
 		com_list_comprehension(c, n);
 	else {
 		int len = 0;

Original file line number	Diff line number	Diff line change
`@@ -1045,7 +1045,7 @@ static void`
`1045`	`1045`	`com_listmaker(struct compiling c, node n)`
`1046`	`1046`	`{`
`1047`	`1047`	`/* listmaker: test ( list_iter \| (',' test)* [','] ) */`
`1048`		`- if (TYPE(CHILD(n, 1)) == list_iter)`
	`1048`	`+ if (NCH(n) > 1 && TYPE(CHILD(n, 1)) == list_iter)`
`1049`	`1049`	`com_list_comprehension(c, n);`
`1050`	`1050`	`else {`
`1051`	`1051`	`int len = 0;`