Remove a few more crashers

Need to check SYM_LIB_TABLE_ENTRY for null but need to check
FP_LIB_TABLE_ENTRY for throwing

eeschema/widgets/panel_symbol_chooser.cpp

@@ -99,7 +99,9 @@ PANEL_SYMBOL_CHOOSER::PANEL_SYMBOL_CHOOSER( SCH_BASE_FRAME* aFrame, wxWindow* aP
                 bool pinned = alg::contains( session.pinned_symbol_libs, nickname )
                                 || alg::contains( project.m_PinnedSymbolLibs, nickname );
 
-                if( libs->FindRow( nickname )->GetIsVisible() )
+                SYMBOL_LIB_TABLE_ROW* row = libs->FindRow( nickname );
+
+                if( row && row->GetIsVisible() )
                     adapter->AddLibrary( nickname, pinned );
             }
         }

pcbnew/footprint_libraries_utils.cpp

@@ -527,10 +527,19 @@ bool FOOTPRINT_EDIT_FRAME::DeleteFootprintFromLibrary( const LIB_ID& aFPID, bool
 
     wxString nickname = aFPID.GetLibNickname();
     wxString fpname = aFPID.GetLibItemName();
+    wxString libfullname;
 
     // Legacy libraries are readable, but modifying legacy format is not allowed
     // So prompt the user if he try to delete a footprint from a legacy lib
-    wxString libfullname = PROJECT_PCB::PcbFootprintLibs( &Prj() )->FindRow( nickname )->GetFullURI();
+    try
+    {
+        libfullname = PROJECT_PCB::PcbFootprintLibs( &Prj() )->FindRow( nickname )->GetFullURI();
+    }
+    catch( ... )
+    {
+        // If we can't find the nickname, stop here
+        return false;
+    }
 
     if( PCB_IO_MGR::GuessPluginTypeFromLibPath( libfullname ) == PCB_IO_MGR::LEGACY )
     {

pcbnew/fp_tree_synchronizing_adapter.cpp

@@ -79,16 +79,26 @@ void FP_TREE_SYNCHRONIZING_ADAPTER::Sync( FP_LIB_TABLE* aLibs )
     {
         const wxString& name = it->get()->m_Name;
 
-        // Remove the library if it no longer exists or it exists in both the global and the
-        // project library but the project library entry is disabled.
-        if( !m_libs->HasLibrary( name, true )
+        try
+        {
+            // Remove the library if it no longer exists or it exists in both the global and the
+            // project library but the project library entry is disabled.
+            if( !m_libs->HasLibrary( name, true )
                 || m_libs->FindRow( name, true ) != m_libs->FindRow( name, false ) )
+            {
+                it = deleteLibrary( it );
+                continue;
+            }
+
+            updateLibrary( *(LIB_TREE_NODE_LIBRARY*) it->get() );
+        }
+        catch( ... )
         {
+            // If the library isn't found, remove it
             it = deleteLibrary( it );
             continue;
         }
 
-        updateLibrary( *(LIB_TREE_NODE_LIBRARY*) it->get() );
         ++it;
     }