From accd08139f9c6782847fc74dcecec9b6729b4d08 Mon Sep 17 00:00:00 2001
From: freestrings <freestrings@gmail.com>
Date: Sun, 16 Feb 2020 13:14:31 +0900
Subject: [PATCH]  Negative slice out of bounds does not return values #35

---
 src/select/mod.rs |  4 ++--
 tests/filter.rs   | 10 ++++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/select/mod.rs b/src/select/mod.rs
index 20ee770..c6f7716 100644
--- a/src/select/mod.rs
+++ b/src/select/mod.rs
@@ -439,9 +439,9 @@ fn walk<'a, F>(vec: &[&'a Value], tmp: &mut Vec<&'a Value>, fun: &F)
 
 fn abs_index(n: isize, len: usize) -> usize {
     if n < 0_isize {
-        (n + len as isize) as usize
+        (n + len as isize).max(0) as usize
     } else {
-        n as usize
+        n.min(len as isize) as usize
     }
 }
 
diff --git a/tests/filter.rs b/tests/filter.rs
index f64588c..8fd220d 100644
--- a/tests/filter.rs
+++ b/tests/filter.rs
@@ -602,6 +602,16 @@ fn range() {
         json!(["first", "second", "third", "forth", "fifth"]),
         json!(["first", "third"]),
     );
+    select_and_then_compare(
+        "$[-4:]",
+        json!(["first", "second", "third"]),
+        json!(["first", "second", "third"]),
+    );
+    select_and_then_compare(
+        "$[:4]",
+        json!(["first", "second", "third"]),
+        json!(["first", "second", "third"]),
+    );
 }
 
 #[test]