From 0fad84fe0656ce8e93409c4f429839879091e44b Mon Sep 17 00:00:00 2001
From: Stephan Hadinger <stephan.hadinger@gmail.com>
Date: Sun, 28 Nov 2021 19:41:26 +0100
Subject: [PATCH] Berry fix ranges with negative indices

---
 lib/libesp32/Berry/src/be_listlib.c |  6 ++++++
 lib/libesp32/Berry/tests/list.be    | 11 +++++++++++
 2 files changed, 17 insertions(+)

diff --git a/lib/libesp32/Berry/src/be_listlib.c b/lib/libesp32/Berry/src/be_listlib.c
index b584aef90..a98b679df 100644
--- a/lib/libesp32/Berry/src/be_listlib.c
+++ b/lib/libesp32/Berry/src/be_listlib.c
@@ -134,9 +134,15 @@ static int item_range(bvm *vm)
     /* get index range */
     be_getmember(vm, 2, "__lower__");
     lower = be_toint(vm, -1);
+    if (lower < 0) {
+        lower = size + lower;
+    }
     be_pop(vm, 1);
     be_getmember(vm, 2, "__upper__");
     upper = be_toint(vm, -1);
+    if (upper < 0) {
+        upper = size + upper;
+    }
     be_pop(vm, 1);
     /* protection scope */
     upper = upper < size ? upper : size - 1;
diff --git a/lib/libesp32/Berry/tests/list.be b/lib/libesp32/Berry/tests/list.be
index d0b9099ba..a2da2ca47 100644
--- a/lib/libesp32/Berry/tests/list.be
+++ b/lib/libesp32/Berry/tests/list.be
@@ -127,3 +127,14 @@ assert([1,2,3].concat('-') == "1-2-3")
 assert([1,"2",3].concat('-') == "1-2-3")
 
 assert(["",2,3].concat('-') == "-2-3")
+
+#- negative indices -#
+assert([1,2,3,4][0] == 1)
+assert([1,2,3,4][-1] == 4)
+assert([1,2,3,4][-2] == 3)
+
+assert([1,2,3,4][1..10] == [2,3,4])
+assert([1,2,3,4][1..-1] == [2,3,4])
+assert([1,2,3,4][1..-2] == [2,3])
+assert([1,2,3,4][3..2] == [])
+assert([1,2,3,4][2..-3] == [])
\ No newline at end of file