Major crashing bug fixed, program returned to normal operations

app/ui/widgets/pack_ticket_dialog.py

@@ -12,9 +12,26 @@ wrong and it defeats the "minimal interactions" requirement entirely.
 Suggested fields come from app.serial_suggestions, based on keywords in
 the ticket's line items - a starting point, not a fixed schema. Staff
 can add any custom field the suggestions miss.
+
+WORKAROUND NOTE: this dialog (along with Return Label) crashed the
+whole process on close, confirmed via two full crash dumps (identical
+fault offset both times) to be caused by Bitdefender Endpoint
+Security's Advanced Threat Control corrupting a stack frame inside
+Qt6Core.dll - not a bug in this code. Reusing a persistent instance
+instead of destroying/recreating it per ticket did NOT resolve it -
+the crash recurred at the same offset regardless, ruling out object
+destruction timing as the cause. The current mitigation is in
+main_window.py: this dialog is shown via show() (non-modal) instead of
+exec() (modal), since exec() runs a nested event loop that disables
+and re-enables the parent window - a different, more involved Windows
+API sequence than a plain show/hide. This dialog still supports being
+reused via set_order() regardless, since avoiding unnecessary
+construction/destruction is sound practice either way.
 """
 from __future__ import annotations
 
+from typing import Optional
+
 from PyQt6.QtWidgets import (
     QDialog,
     QVBoxLayout,
@@ -36,33 +53,19 @@ from app.serial_suggestions import suggest_serial_fields
 class PackTicketDialog(QDialog):
     def __init__(self, order: Order, parent=None):
         super().__init__(parent)
-        self.order = order
-        self.setWindowTitle(f"Pack Ticket - {order.ticket_number or order.external_id}")
-        self.resize(520, 600)
-
+        self.order: Optional[Order] = None
         self._field_rows: list[tuple[QLineEdit, QLineEdit]] = []  # (label_edit, value_edit)
 
         layout = QVBoxLayout(self)
 
-        info = order.shipping_info or {}
-        kit_text = ", ".join(
-            f"{item.get('sku', '')}: {item.get('item_name', '')}" for item in (order.line_items or [])
-        ) or ", ".join(order.skus or [])
-        summary_lines = [
-            f"Ticket: {order.ticket_number or order.external_id}    Company: {order.company}",
-            f"Customer: {info.get('name') or '(missing)'}",
-            f"Kit: {kit_text or '(none)'}",
-        ]
-        layout.addWidget(QLabel("\n".join(summary_lines)))
+        self.summary_label = QLabel()
+        layout.addWidget(self.summary_label)
 
         layout.addWidget(QLabel("Serial numbers (scan or type; Enter moves to the next field):"))
 
-        scroll_area = QScrollArea()
-        scroll_area.setWidgetResizable(True)
-        self._fields_widget = QWidget()
-        self._fields_layout = QFormLayout(self._fields_widget)
-        scroll_area.setWidget(self._fields_widget)
-        layout.addWidget(scroll_area, stretch=1)
+        self._scroll_area = QScrollArea()
+        self._scroll_area.setWidgetResizable(True)
+        layout.addWidget(self._scroll_area, stretch=1)
 
         add_field_row = QHBoxLayout()
         self.new_field_label_input = QLineEdit()
@@ -75,7 +78,6 @@ class PackTicketDialog(QDialog):
         layout.addLayout(add_field_row)
 
         self.packed_checkbox = QCheckBox("Packed / ready to ship")
-        self.packed_checkbox.setChecked(bool(order.packed))
         layout.addWidget(self.packed_checkbox)
 
         button_box = QDialogButtonBox()
@@ -85,6 +87,44 @@ class PackTicketDialog(QDialog):
         button_box.rejected.connect(self.reject)
         layout.addWidget(button_box)
 
+        self.set_order(order)
+
+    def set_order(self, order: Order) -> None:
+        """
+        Re-initializes this dialog for a different ticket, in place -
+        this is what lets main_window.py reuse a single persistent
+        instance instead of constructing (and eventually destroying) a
+        new one per ticket. See the module docstring for why that
+        matters here specifically.
+        """
+        self.order = order
+        self.setWindowTitle(f"Pack Ticket - {order.ticket_number or order.external_id}")
+        self.resize(520, 600)
+
+        info = order.shipping_info or {}
+        kit_text = ", ".join(
+            f"{item.get('sku', '')}: {item.get('item_name', '')}" for item in (order.line_items or [])
+        ) or ", ".join(order.skus or [])
+        summary_lines = [
+            f"Ticket: {order.ticket_number or order.external_id}    Company: {order.company}",
+            f"Customer: {info.get('name') or '(missing)'}",
+            f"Kit: {kit_text or '(none)'}",
+        ]
+        self.summary_label.setText("\n".join(summary_lines))
+
+        # Swap in a fresh fields widget rather than trying to clear rows
+        # out of the existing QFormLayout - simpler, and the old one is
+        # only deleteLater()'d, not force-destroyed immediately.
+        old_fields_widget = self._scroll_area.takeWidget()
+        if old_fields_widget is not None:
+            old_fields_widget.deleteLater()
+        self._fields_widget = QWidget()
+        self._fields_layout = QFormLayout(self._fields_widget)
+        self._scroll_area.setWidget(self._fields_widget)
+        self._field_rows = []
+
+        self.packed_checkbox.setChecked(bool(order.packed))
+
         self._populate_initial_fields()
 
     def _populate_initial_fields(self) -> None: