From 972c5501d76eb9a98058e1f823155711eddcab46 Mon Sep 17 00:00:00 2001
From: nemtrif <ntrifunovic@hotmail.com>
Date: Sat, 28 Oct 2023 11:14:26 -0400
Subject: [PATCH] Fix for issue #111

Fixing regression caused by the fix for #78, which leads to utf8::unchecked::utf16to8() chopping off the last character in many cases.
---
 source/utf8/unchecked.h | 4 ++--
 tests/test_cpp11.cpp    | 5 +++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/source/utf8/unchecked.h b/source/utf8/unchecked.h
index 6f928b7..65d4948 100644
--- a/source/utf8/unchecked.h
+++ b/source/utf8/unchecked.h
@@ -183,10 +183,10 @@ namespace utf8
         {
             while (start != end) {
                 utfchar32_t cp = utf8::internal::mask16(*start++);
-                if (start == end)
-                    return result;
                 // Take care of surrogate pairs first
                 if (utf8::internal::is_lead_surrogate(cp)) {
+                    if (start == end)
+                        return result;
                     utfchar32_t trail_surrogate = utf8::internal::mask16(*start++);
                     cp = (cp << 10) + trail_surrogate + internal::SURROGATE_OFFSET;
                 }
diff --git a/tests/test_cpp11.cpp b/tests/test_cpp11.cpp
index ee3518a..e521966 100644
--- a/tests/test_cpp11.cpp
+++ b/tests/test_cpp11.cpp
@@ -50,6 +50,11 @@ TEST(CPP11APITests, test_utf16to8)
     u16string utf16string = {0x41, 0x0448, 0x65e5, 0xd834, 0xdd1e};
     string u = utf16to8(utf16string);
     EXPECT_EQ (u.size(), 10);
+
+    u16string h16 = u"h!";
+    string h8;
+    utf8::unchecked::utf16to8(h16.begin(), h16.end(), std::back_inserter(h8));
+    EXPECT_EQ (h8, "h!");
 }
 
 TEST(CPP11APITests, test_utf8to16)