From: Guido van Rossum <guido@python.org>
Date: Mon, 28 Jan 2019 16:34:32 +0000 (-0800)
Subject: Add guards to some '== TYPE_COMMENT' checks, hopefully fixing a crash
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1667b8c40557fa2e47fbd78dacae709383d83aa6;p=thirdparty%2FPython%2Fcpython.git

Add guards to some '== TYPE_COMMENT' checks, hopefully fixing a crash
---

diff --git a/Python/ast.c b/Python/ast.c
index e18b20ea003e..0da33f7a9c0d 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -1538,7 +1538,7 @@ ast_for_arguments(struct compiling *c, const node *n)
                     return NULL;
                 asdl_seq_SET(posargs, k++, arg);
                 i += 1; /* the name */
-                if (TYPE(CHILD(n, i)) == COMMA)
+                if (i < NCH(n) && TYPE(CHILD(n, i)) == COMMA)
                     i += 1; /* the comma, if present */
                 break;
             case STAR:
@@ -1554,7 +1554,7 @@ ast_for_arguments(struct compiling *c, const node *n)
                     int res = 0;
                     i += 2; /* now follows keyword only arguments */
 
-                    if (TYPE(CHILD(n, i)) == TYPE_COMMENT) {
+                    if (i < NCH(n) && TYPE(CHILD(n, i)) == TYPE_COMMENT) {
                         ast_error(c, CHILD(n, i),
                                 "bare * has associated type comment");
                         return NULL;
@@ -1571,10 +1571,10 @@ ast_for_arguments(struct compiling *c, const node *n)
                         return NULL;
 
                 i += 2; /* the star and the name */
-                if (TYPE(CHILD(n, i)) == COMMA)
+                if (i < NCH(n) && TYPE(CHILD(n, i)) == COMMA)
                     i += 1; /* the comma, if present */
 
-                    if (TYPE(CHILD(n, i)) == TYPE_COMMENT) {
+                if (i < NCH(n) && TYPE(CHILD(n, i)) == TYPE_COMMENT) {
                         vararg->type_comment = NEW_TYPE_COMMENT(CHILD(n, i));
                         i += 1;
                     }