Forward port MvL's fix in 43227:
Fix crash when a Unicode string containing an encoding declaration is
compile()d. Fixes #1115379.
diff --git a/Python/ast.c b/Python/ast.c
index 3c339f0..30275a6 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -191,6 +191,10 @@
if (flags && flags->cf_flags & PyCF_SOURCE_IS_UTF8) {
c.c_encoding = "utf-8";
+ if (TYPE(n) == encoding_decl) {
+ ast_error(n, "encoding declaration in Unicode string");
+ goto error;
+ }
} else if (TYPE(n) == encoding_decl) {
c.c_encoding = STR(n);
n = CHILD(n, 0);