ask user before creating a clipboard larger than 5 MB

bigtext.py

@@ -12,6 +12,7 @@ from PyQt6.QtGui import QMouseEvent
 from PyQt6.QtWidgets import *
 
 from ScaledScrollBar import ScaledScrollBar
+from conversion import humanbytes
 from highlight import Highlight
 from highlight_regex import HighlightRegex
 from highlight_selection import HighlightSelection
@@ -227,6 +228,20 @@ class InnerBigText(QWidget):
         if self.selection_highlight.start_byte != self.selection_highlight.end_byte:
             start = min(self.selection_highlight.start_byte, self.selection_highlight.end_byte)
             end = max(self.selection_highlight.start_byte, self.selection_highlight.end_byte)
+            if end - start > (1024 ** 2) * 5:
+                you_sure = QMessageBox(
+                    QMessageBox.Icon.Warning,
+                    self.tr("copy to clipboard"),
+                    self.tr(
+                        "You are about to copy <b>%s</b> to the clipboard. Are you sure you want to do that?" % humanbytes(
+                            end - start)))
+                you_sure.setStandardButtons(QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No)
+                you_sure.setDefaultButton(QMessageBox.StandardButton.No)
+                result = you_sure.exec()
+                if result != QMessageBox.StandardButton.Yes:
+                    # abort
+                    return
+
             selected_text = self.model.read_range(start, end)
             cb = QApplication.clipboard()
             cb.setText(selected_text)