From f4ee4da8ce39f262b506a0b102b69a3c6ae28c8b Mon Sep 17 00:00:00 2001
From: Jeremy Rimpo <jrim@rimpo.org>
Date: Wed, 29 Nov 2023 00:10:10 -0600
Subject: [PATCH 1/2] Fix string conversion issues with emoji characters

---
 src/pybind11-qt/pybind11_qt_basic.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/pybind11-qt/pybind11_qt_basic.cpp b/src/pybind11-qt/pybind11_qt_basic.cpp
index 56ddf4f..d584eae 100644
--- a/src/pybind11-qt/pybind11_qt_basic.cpp
+++ b/src/pybind11-qt/pybind11_qt_basic.cpp
@@ -46,6 +46,10 @@ namespace pybind11::detail {
         PyObject* strPtr =
             PyUnicode_Check(objPtr) ? PyUnicode_AsUTF8String(objPtr) : objPtr;
 
+        if (!strPtr) {
+            return false;
+        }
+
         // Extract the character data from the python string
         value = QString::fromUtf8(PyBytes_AsString(strPtr));
 
@@ -68,8 +72,7 @@ namespace pybind11::detail {
                                       handle /* parent */)
     {
         static_assert(sizeof(QChar) == 2);
-        return PyUnicode_FromKindAndData(PyUnicode_2BYTE_KIND, src.constData(),
-                                         src.length());
+        return PyUnicode_FromString(src.toStdString().c_str());
     }
 
     bool type_caster<QVariant>::load(handle src, bool)

From aac872c5f5d73bf1ee739fce4f1c18c60b6b386b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mika=C3=ABl=20Capelle?= <capelle.mikael@gmail.com>
Date: Sat, 2 Dec 2023 17:31:25 +0100
Subject: [PATCH 2/2] Fix load/cast of QString to avoid issues with surrogate
 pairs.

---
 src/pybind11-qt/pybind11_qt_basic.cpp | 46 +++++++++++++++------------
 tests/python/test_qt.cpp              |  8 +++++
 tests/python/test_qt.py               |  9 ++++++
 3 files changed, 43 insertions(+), 20 deletions(-)

diff --git a/src/pybind11-qt/pybind11_qt_basic.cpp b/src/pybind11-qt/pybind11_qt_basic.cpp
index d584eae..d82ec2b 100644
--- a/src/pybind11-qt/pybind11_qt_basic.cpp
+++ b/src/pybind11-qt/pybind11_qt_basic.cpp
@@ -35,30 +35,36 @@ namespace pybind11::detail {
      */
     bool type_caster<QString>::load(handle src, bool)
     {
-
         PyObject* objPtr = src.ptr();
 
-        if (!PyBytes_Check(objPtr) && !PyUnicode_Check(objPtr)) {
-            return false;
+        if (PyBytes_Check(objPtr)) {
+            value = QString::fromUtf8(PyBytes_AsString(objPtr));
+            return true;
         }
+        else if (PyUnicode_Check(objPtr)) {
+            switch (PyUnicode_KIND(objPtr)) {
+            case PyUnicode_1BYTE_KIND:
+                value = QString::fromUtf8(PyUnicode_AsUTF8(objPtr));
+                break;
+            case PyUnicode_2BYTE_KIND:
+                value = QString::fromUtf16(
+                    reinterpret_cast<char16_t*>(PyUnicode_2BYTE_DATA(objPtr)),
+                    PyUnicode_GET_LENGTH(objPtr));
+                break;
+            case PyUnicode_4BYTE_KIND:
+                value = QString::fromUcs4(
+                    reinterpret_cast<char32_t*>(PyUnicode_4BYTE_DATA(objPtr)),
+                    PyUnicode_GET_LENGTH(objPtr));
+                break;
+            default:
+                return false;
+            }
 
-        // Ensure the string uses 8-bit characters
-        PyObject* strPtr =
-            PyUnicode_Check(objPtr) ? PyUnicode_AsUTF8String(objPtr) : objPtr;
-
-        if (!strPtr) {
-            return false;
+            return true;
         }
-
-        // Extract the character data from the python string
-        value = QString::fromUtf8(PyBytes_AsString(strPtr));
-
-        // Deallocate local copy if one was made
-        if (strPtr != objPtr) {
-            Py_DecRef(strPtr);
+        else {
+            return false;
         }
-
-        return true;
     }
 
     /**
@@ -71,8 +77,8 @@ namespace pybind11::detail {
     handle type_caster<QString>::cast(QString src, return_value_policy /* policy */,
                                       handle /* parent */)
     {
-        static_assert(sizeof(QChar) == 2);
-        return PyUnicode_FromString(src.toStdString().c_str());
+        return PyUnicode_DecodeUTF16(reinterpret_cast<const char*>(src.utf16()),
+                                     2 * src.length(), nullptr, 0);
     }
 
     bool type_caster<QVariant>::load(handle src, bool)
diff --git a/tests/python/test_qt.cpp b/tests/python/test_qt.cpp
index 8d7cb1e..35b1785 100644
--- a/tests/python/test_qt.cpp
+++ b/tests/python/test_qt.cpp
@@ -11,6 +11,14 @@ PYBIND11_MODULE(qt, m)
 {
     // QString
 
+    m.def("create_qstring_with_emoji", []() {
+        return QString::fromUtf16(u"\U0001F600");
+    });
+
+    m.def("consume_qstring_with_emoji", [](QString const& qstring) {
+        return qstring.length();
+    });
+
     m.def("qstring_to_stdstring", [](QString const& qstring) {
         return qstring.toStdString();
     });
diff --git a/tests/python/test_qt.py b/tests/python/test_qt.py
index cb35db5..5bbfd49 100644
--- a/tests/python/test_qt.py
+++ b/tests/python/test_qt.py
@@ -10,10 +10,19 @@ def test_qstring():
 
     assert m.qstring_to_stdstring("éàüö") == "éàüö"
     assert m.stdstring_to_qstring("éàüö") == "éàüö"
+    assert m.qstring_to_stdstring("خالد") == "خالد"
+    assert m.qstring_to_stdstring("🌎") == "🌎"
 
     assert m.qstring_to_int("2") == 2
     assert m.int_to_qstring(2) == "2"
 
+    emoji = m.create_qstring_with_emoji()
+
+    assert emoji.encode("utf-16be", "surrogatepass") == b"\xd8\x3d\xde\x00"
+    assert m.consume_qstring_with_emoji(emoji) == 2
+
+    assert m.consume_qstring_with_emoji("🌎") == 2
+
 
 def test_qstringlist():
     assert m.qstringlist_join([""], "--") == ""