From 41f2a6f8a42a4b1135aaed05a3b17c9ea001b3e1 Mon Sep 17 00:00:00 2001
From: hius07 <62179190+hius07@users.noreply.github.com>
Date: Thu, 15 Jul 2021 22:57:12 +0300
Subject: [PATCH] InputText: fix search on multi-bytes UTF-8 (#7981)

Also fix crashes when text is invalid UTF-8.
---
 frontend/ui/widget/inputtext.lua | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/frontend/ui/widget/inputtext.lua b/frontend/ui/widget/inputtext.lua
index f7904edfd..313cc96c1 100644
--- a/frontend/ui/widget/inputtext.lua
+++ b/frontend/ui/widget/inputtext.lua
@@ -673,19 +673,19 @@ end
 -- if start_pos not set, starts a search from the next to cursor position
 -- returns first found position or 0 if not found
 function InputText:searchString(str, case_sensitive, start_pos)
-    local str_len = string.len(str)
+    local str_charlist = util.splitToChars(str)
+    local str_len = #str_charlist
     local char_pos, found = 0, 0
     start_pos = start_pos and (start_pos - 1) or self.charpos
-    if not case_sensitive then
-        str = Utf8Proc.lowercase(str)
-    end
     for i = start_pos, #self.charlist - str_len do
         for j = 1, str_len do
             local char_txt = self.charlist[i + j]
+            local char_str = str_charlist[j]
             if not case_sensitive then
-                char_txt = Utf8Proc.lowercase(char_txt)
+                char_txt = Utf8Proc.lowercase(util.fixUtf8(char_txt, "?"))
+                char_str = Utf8Proc.lowercase(util.fixUtf8(char_str, "?"))
             end
-            if char_txt ~= string.sub(str, j, j) then
+            if char_txt ~= char_str then
                 found = 0
                 break
             end