From 6c26009f196568a19e393b8eb1e45f0ae9567f77 Mon Sep 17 00:00:00 2001
From: Aaron van Geffen <aaron@aaronweb.net>
Date: Sat, 23 Dec 2017 02:39:09 +0100
Subject: [PATCH] Fix #6097: String::Trim wasn't taking multibyte chars into
 account.
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Extends StringTest with multibyte tests.
NB: ストリング is a katakana transcription of 'string'.
---
 src/openrct2/core/String.cpp | 10 ++++++++--
 test/tests/StringTest.cpp    |  2 ++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/openrct2/core/String.cpp b/src/openrct2/core/String.cpp
index 9dcd88ca38..8b45f6e928 100644
--- a/src/openrct2/core/String.cpp
+++ b/src/openrct2/core/String.cpp
@@ -469,7 +469,10 @@ namespace String
         if (firstNonWhitespace != nullptr &&
             firstNonWhitespace != str)
         {
-            size_t newStringSize = ch - firstNonWhitespace;
+            // Take multibyte characters into account: use the last byte of the
+            // current character.
+            size_t newStringSize = (nextCh - 1) - firstNonWhitespace;
+
 #ifdef DEBUG
             size_t currentStringSize = String::SizeOf(str);
             Guard::Assert(newStringSize < currentStringSize, GUARD_LINE);
@@ -523,7 +526,10 @@ namespace String
                 {
                     startSubstr = ch;
                 }
-                endSubstr = ch;
+
+                // Take multibyte characters into account: move pointer towards
+                // the last byte of the current character.
+                endSubstr = nextCh - 1;
             }
             ch = nextCh;
         }
diff --git a/test/tests/StringTest.cpp b/test/tests/StringTest.cpp
index 7280eb6200..5b481c5535 100644
--- a/test/tests/StringTest.cpp
+++ b/test/tests/StringTest.cpp
@@ -16,6 +16,8 @@ INSTANTIATE_TEST_CASE_P(TrimData, StringTest, testing::Values(
     TCase("string  ", "string"),
     TCase("   some   string  ", "some   string"),
     TCase("      ", ""),
+    TCase(" ストリング", "ストリング"),
+    TCase("ストリング ", "ストリング"),
     TCase("", ""),
     TCase("\n", ""),
     TCase("\n\n\n\r\n", ""),