From 153d1e354133b6313ff827908a0008861c0a9f2b Mon Sep 17 00:00:00 2001
From: Matthias Koefferlein <matthias@klayout.de>
Date: Fri, 13 Sep 2024 14:31:45 +0200
Subject: [PATCH] Trying to improve stability under PCell debugging conditions
 inside the IDE

---
 src/db/db/dbLayout.cc       |  3 +++
 src/db/db/dbLibraryProxy.cc | 19 ++++++++++---------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/db/db/dbLayout.cc b/src/db/db/dbLayout.cc
index d31cc36ac..b69ca8d73 100644
--- a/src/db/db/dbLayout.cc
+++ b/src/db/db/dbLayout.cc
@@ -2876,6 +2876,9 @@ Layout::get_context_info (cell_index_type cell_index, LayoutOrCellContextInfo &i
 
       //  one level of library indirection
       ly = &lib->layout ();
+      if (! ly->is_valid_cell_index (lib_proxy->library_cell_index ())) {
+        return any_meta; //  abort
+      }
       cptr = &ly->cell (lib_proxy->library_cell_index ());
       info.lib_name = lib->get_name ();
 
diff --git a/src/db/db/dbLibraryProxy.cc b/src/db/db/dbLibraryProxy.cc
index 1bb78a8a7..ff86a6f5e 100644
--- a/src/db/db/dbLibraryProxy.cc
+++ b/src/db/db/dbLibraryProxy.cc
@@ -132,6 +132,7 @@ LibraryProxy::get_layer_indices (db::Layout &layout, db::ImportLayerMapping *lay
 
   Library *lib = LibraryManager::instance ().lib (lib_id ());
   tl_assert (lib != 0);
+  tl_assert (lib->layout ().is_valid_cell_index (library_cell_index ()));
 
   const db::Cell &cell = lib->layout ().cell (library_cell_index ());
 
@@ -247,11 +248,11 @@ LibraryProxy::get_basic_name () const
 {
   Library *lib = LibraryManager::instance ().lib (lib_id ());
   if (lib) {
-    const db::Cell *lib_cell = &lib->layout ().cell (library_cell_index ());
-    if (! lib_cell) {
+    if (! lib->layout ().is_valid_cell_index (library_cell_index ())) {
       return "<defunct>";
     } else {
-      return lib_cell->get_basic_name ();
+      const db::Cell &lib_cell = lib->layout ().cell (library_cell_index ());
+      return lib_cell.get_basic_name ();
     }
   } else {
     return Cell::get_basic_name ();
@@ -263,11 +264,11 @@ LibraryProxy::get_display_name () const
 {
   Library *lib = LibraryManager::instance ().lib (lib_id ());
   if (lib) {
-    const db::Cell *lib_cell = &lib->layout ().cell (library_cell_index ());
-    if (! lib_cell) {
+    if (! lib->layout ().is_valid_cell_index (library_cell_index ())) {
       return lib->get_name () + "." + "<defunct>";
     } else {
-      return lib->get_name () + "." + lib_cell->get_display_name ();
+      const db::Cell &lib_cell = lib->layout ().cell (library_cell_index ());
+      return lib->get_name () + "." + lib_cell.get_display_name ();
     }
   } else {
     return Cell::get_display_name ();
@@ -279,11 +280,11 @@ LibraryProxy::get_qualified_name () const
 {
   Library *lib = LibraryManager::instance ().lib (lib_id ());
   if (lib) {
-    const db::Cell *lib_cell = &lib->layout ().cell (library_cell_index ());
-    if (! lib_cell) {
+    if (! lib->layout ().is_valid_cell_index (library_cell_index ())) {
       return lib->get_name () + "." + "<defunct>";
     } else {
-      return lib->get_name () + "." + lib_cell->get_qualified_name ();
+      const db::Cell &lib_cell = lib->layout ().cell (library_cell_index ());
+      return lib->get_name () + "." + lib_cell.get_qualified_name ();
     }
   } else {
     return Cell::get_qualified_name ();