details: https://hg.nginx.org/njs/rev/6be62551e6d4
branches:
changeset: 1081:6be62551e6d4
user: Valentin Bartenev <vbart@nginx.com>
date: Sun Jul 28 17:19:51 2019 +0300
description:
Fixed undefined behaviour in left shift of negative numbers.

Now it's implementation defined.

diffstat:

njs/njs_vmcode.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diffs (13 lines):

diff -r 07989e97b198 -r 6be62551e6d4 njs/njs_vmcode.c
--- a/njs/njs_vmcode.c Sun Jul 28 15:00:40 2019 +0300
+++ b/njs/njs_vmcode.c Sun Jul 28 17:19:51 2019 +0300
@@ -421,7 +421,8 @@ next:
i32 = njs_number_to_int32(num);

if (op == NJS_VMCODE_LEFT_SHIFT) {
- i32 <<= u32;
+ /* Shifting of negative numbers is undefined. */
+ i32 = (uint32_t) i32 << u32;
} else {
i32 >>= u32;
}
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