From f951d0241c8808ae6c0672dca7d51fec28c9fb9f Mon Sep 17 00:00:00 2001 From: William Langford Date: Fri, 22 Feb 2019 19:33:24 -0500 Subject: [PATCH] Change contains to return true for empty string needles The behavior of memmem for an empty needle is inconsistent between implementations of libc. Our tests imply that we want an empty string needle to be true, so check for an empty needle before calling memmem. --- src/jv.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/src/jv.c b/src/jv.c index 06b4e6a2..2427b009 100644 --- a/src/jv.c +++ b/src/jv.c @@ -1344,8 +1344,13 @@ int jv_contains(jv a, jv b) { } else if (jv_get_kind(a) == JV_KIND_ARRAY) { r = jv_array_contains(jv_copy(a), jv_copy(b)); } else if (jv_get_kind(a) == JV_KIND_STRING) { - r = _jq_memmem(jv_string_value(a), jv_string_length_bytes(jv_copy(a)), - jv_string_value(b), jv_string_length_bytes(jv_copy(b))) != 0; + int b_len = jv_string_length_bytes(jv_copy(b)); + if (b_len != 0) { + r = _jq_memmem(jv_string_value(a), jv_string_length_bytes(jv_copy(a)), + jv_string_value(b), b_len) != 0; + } else { + r = 1; + } } else { r = jv_equal(jv_copy(a), jv_copy(b)); }