From 6b19ede1a5b500d66e8edaef6e8d80492ed9f74f Mon Sep 17 00:00:00 2001
From: David Gumberg <davidzgumberg@gmail.com>
Date: Wed, 3 Sep 2025 16:00:31 -0700
Subject: [PATCH] gui: Avoid pathological QT text/markdown behavior...

during text selection by only setting plaintext mime data.

Github-Pull: https://github.com/bitcoin-core/gui/pull/886
Rebased-From: 6a371b70c87ad6b763c89384562fce8549f37434
---
 src/qt/forms/debugwindow.ui |  6 +++++-
 src/qt/rpcconsole.h         | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/qt/forms/debugwindow.ui b/src/qt/forms/debugwindow.ui
index eccea143189..d1c627bb3ce 100644
--- a/src/qt/forms/debugwindow.ui
+++ b/src/qt/forms/debugwindow.ui
@@ -573,7 +573,7 @@
         </layout>
        </item>
        <item>
-        <widget class="QTextEdit" name="messagesWidget">
+        <widget class="PlainCopyTextEdit" name="messagesWidget">
          <property name="minimumSize">
           <size>
            <width>0</width>
@@ -1868,6 +1868,10 @@
     <slot>clear()</slot>
    </slots>
   </customwidget>
+  <customwidget>
+   <class>PlainCopyTextEdit</class>
+   <extends>QTextEdit</extends>
+  </customwidget>
  </customwidgets>
  <resources>
   <include location="../bitcoin.qrc"/>
diff --git a/src/qt/rpcconsole.h b/src/qt/rpcconsole.h
index a1b9522b98e..fe2955cc26b 100644
--- a/src/qt/rpcconsole.h
+++ b/src/qt/rpcconsole.h
@@ -15,6 +15,9 @@
 
 #include <QByteArray>
 #include <QCompleter>
+#include <QMimeData>
+#include <QTextDocumentFragment>
+#include <QTextEdit>
 #include <QThread>
 #include <QWidget>
 
@@ -191,4 +194,20 @@ private Q_SLOTS:
     void updateAlerts(const QString& warnings);
 };
 
+/**
+ * A version of QTextEdit that only populates plaintext mime data from a
+ * selection, this avoids some bad behavior in QT's HTML->Markdown conversion.
+ */
+class PlainCopyTextEdit : public QTextEdit {
+    Q_OBJECT
+public:
+    using QTextEdit::QTextEdit;
+protected:
+    QMimeData* createMimeDataFromSelection() const override {
+        auto md = new QMimeData();
+        md->setText(textCursor().selection().toPlainText());
+        return md;
+    }
+};
+
 #endif // BITCOIN_QT_RPCCONSOLE_H