fix(lua): make vim.str_utfindex and vim.str_byteindex handle NUL bytes

fixes #16290

1 files changed, 8 insertions, 4 deletions

diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index cd3240cd30..33f4b108da 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -158,17 +158,20 @@ describe('lua stdlib', function()
   end)
 
   it("vim.str_utfindex/str_byteindex", function()
-    exec_lua([[_G.test_text = "xy åäö ɧ 汉语 ↥ 🤦x🦄 å بِيَّ"]])
-    local indicies32 = {[0]=0,1,2,3,5,7,9,10,12,13,16,19,20,23,24,28,29,33,34,35,37,38,40,42,44,46,48}
-    local indicies16 = {[0]=0,1,2,3,5,7,9,10,12,13,16,19,20,23,24,28,28,29,33,33,34,35,37,38,40,42,44,46,48}
+    exec_lua([[_G.test_text = "xy åäö ɧ 汉语 ↥ 🤦x🦄 å بِيَّ\000ъ"]])
+    local indicies32 = {[0]=0,1,2,3,5,7,9,10,12,13,16,19,20,23,24,28,29,33,34,35,37,38,40,42,44,46,48,49,51}
+    local indicies16 = {[0]=0,1,2,3,5,7,9,10,12,13,16,19,20,23,24,28,28,29,33,33,34,35,37,38,40,42,44,46,48,49,51}
     for i,k in pairs(indicies32) do
       eq(k, exec_lua("return vim.str_byteindex(_G.test_text, ...)", i), i)
     end
     for i,k in pairs(indicies16) do
       eq(k, exec_lua("return vim.str_byteindex(_G.test_text, ..., true)", i), i)
     end
+    matches(": index out of range$", pcall_err(exec_lua, "return vim.str_byteindex(_G.test_text, ...)", #indicies32 + 1))
+    matches(": index out of range$", pcall_err(exec_lua, "return vim.str_byteindex(_G.test_text, ..., true)", #indicies16 + 1))
     local i32, i16 = 0, 0
-    for k = 0,48 do
+    local len = 51
+    for k = 0,len do
       if indicies32[i32] < k then
         i32 = i32 + 1
       end
@@ -180,6 +183,7 @@ describe('lua stdlib', function()
       end
       eq({i32, i16}, exec_lua("return {vim.str_utfindex(_G.test_text, ...)}", k), k)
     end
+    matches(": index out of range$", pcall_err(exec_lua, "return vim.str_utfindex(_G.test_text, ...)", len + 1))
   end)
 
   it("vim.str_utf_start", function()