From ef6f3f182a54dea97f69bb2c7e8e3b8291c08813 Mon Sep 17 00:00:00 2001
From: Matthias Koefferlein <matthias@koefferlein.de>
Date: Wed, 4 Jan 2023 21:17:12 +0100
Subject: [PATCH] Fixed issue #1242 (KLayout 0.28.2 crashes when registering a
 plugin if a layout exists)

Problem was twofold: first, events are triggered during
construction of the plugin which met an uninitialized
pointer. Second, the clearing of existing plugins failed
because of iterating a vector while destroying it's members
erased member of it.
---
 src/laybasic/laybasic/layLayoutViewBase.cc |  5 ++--
 src/layview/layview/layLayoutView_qt.cc    | 16 ++++++++---
 testdata/ruby/layLayoutView.rb             | 33 ++++++++++++++++++++++
 3 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/src/laybasic/laybasic/layLayoutViewBase.cc b/src/laybasic/laybasic/layLayoutViewBase.cc
index e27ee26b1..5bd487cbf 100644
--- a/src/laybasic/laybasic/layLayoutViewBase.cc
+++ b/src/laybasic/laybasic/layLayoutViewBase.cc
@@ -578,10 +578,11 @@ void LayoutViewBase::drop_url (const std::string &path_or_url)
 
 void LayoutViewBase::clear_plugins ()
 {
-  for (std::vector<lay::Plugin *>::iterator p = mp_plugins.begin (); p != mp_plugins.end (); ++p) {
+  std::vector<lay::Plugin *> plugins;
+  mp_plugins.swap (plugins);
+  for (std::vector<lay::Plugin *>::iterator p = plugins.begin (); p != plugins.end (); ++p) {
     delete *p;
   }
-  mp_plugins.clear ();
   mp_active_plugin = 0;
 }
 
diff --git a/src/layview/layview/layLayoutView_qt.cc b/src/layview/layview/layLayoutView_qt.cc
index 495c9beab..90f7b6ea4 100644
--- a/src/layview/layview/layLayoutView_qt.cc
+++ b/src/layview/layview/layLayoutView_qt.cc
@@ -98,15 +98,23 @@ namespace lay
 //  LayoutViewWidget implementation
 
 LayoutViewWidget::LayoutViewWidget (db::Manager *mgr, bool editable, lay::Plugin *plugin_parent, QWidget *parent, unsigned int options)
-  : QFrame (parent)
+  : QFrame (parent), mp_view (0)
 {
-  mp_view = new LayoutView (mgr, editable, plugin_parent, this, options);
+  //  NOTE: construction the LayoutView may trigger events (script code executed etc.) which must
+  //  not meet an invalid mp_view pointer (e.g. in eventFilter). Hence, mp_view is 0 first, and set only
+  //  after the LayoutView is successfully constructed.
+  std::unique_ptr<LayoutView> view (new LayoutView (mgr, editable, plugin_parent, this, options));
+  mp_view = view.release ();
 }
 
 LayoutViewWidget::LayoutViewWidget (lay::LayoutView *source, db::Manager *mgr, bool editable, lay::Plugin *plugin_parent, QWidget *parent, unsigned int options)
-  : QFrame (parent)
+  : QFrame (parent), mp_view (0)
 {
-  mp_view = new LayoutView (source, mgr, editable, plugin_parent, this, options);
+  //  NOTE: construction the LayoutView may trigger events (script code executed etc.) which must
+  //  not meet an invalid mp_view pointer (e.g. in eventFilter). Hence, mp_view is 0 first, and set only
+  //  after the LayoutView is successfully constructed.
+  std::unique_ptr<LayoutView> view (new LayoutView (source, mgr, editable, plugin_parent, this, options));
+  mp_view = view.release ();
 }
 
 LayoutViewWidget::~LayoutViewWidget ()
diff --git a/testdata/ruby/layLayoutView.rb b/testdata/ruby/layLayoutView.rb
index 6aeccd326..c22c891d8 100644
--- a/testdata/ruby/layLayoutView.rb
+++ b/testdata/ruby/layLayoutView.rb
@@ -498,6 +498,39 @@ class LAYLayoutView_TestClass < TestBase
 
   end
 
+  class DummyPlugin < RBA::Plugin
+    def initialize(manager, view)
+      self.manager = manager
+      self.view = view
+    end
+  end
+
+  class DummyPluginFactory < RBA::PluginFactory
+    def initialize()
+      register(1000, "dummy_plugin", "Dummy Plugin")
+    end
+    def create_plugin(manager, unused, view)
+      DummyPlugin::new(manager, view)
+    end
+  end
+
+  # issue-1242
+  def test_6
+
+    # Create a new layout
+    main_window = RBA::MainWindow.instance()
+    main_window.close_all
+    main_window.create_layout(2)
+
+    # Register plugin -> crashes in issue-1242
+    dpi = DummyPluginFactory::new
+
+    main_window.close_all
+
+    dpi._destroy
+
+  end
+
 end
 
 load("test_epilogue.rb")