Fixed issue #1993 ('with_area' modifies result of 'join')

Root cause was a held layout lock inside the TilingProcessor.
As that object was not always released inside the Ruby
DRC script, the lock was held sometimes longer than
needed and messed with the hierarchy system.

src/db/db/dbOriginalLayerEdgePairs.cc

@@ -181,7 +181,7 @@ OriginalLayerEdgePairs::begin_iter () const
 bool
 OriginalLayerEdgePairs::empty () const
 {
-  return m_iter.at_end ();
+  return m_iter.at_end_no_lock ();
 }
 
 const db::EdgePair *

src/db/db/dbOriginalLayerEdges.cc

@@ -218,7 +218,7 @@ OriginalLayerEdges::begin_merged_iter () const
 bool
 OriginalLayerEdges::empty () const
 {
-  return m_iter.at_end ();
+  return m_iter.at_end_no_lock ();
 }
 
 bool

src/db/db/dbOriginalLayerRegion.cc

@@ -330,11 +330,7 @@ OriginalLayerRegion::begin_merged_iter () const
 bool
 OriginalLayerRegion::empty () const
 {
-  //  NOTE: we should to make sure the iterator isn't validated as this would spoil the usability or OriginalLayerRegion upon
-  //  layout changes
-  db::RecursiveShapeIterator iter = m_iter;
-
-  return iter.at_end ();
+  return m_iter.at_end_no_lock ();
 }
 
 bool

src/db/db/dbOriginalLayerTexts.cc

@@ -181,7 +181,7 @@ OriginalLayerTexts::begin_iter () const
 bool
 OriginalLayerTexts::empty () const
 {
-  return m_iter.at_end ();
+  return m_iter.at_end_no_lock ();
 }
 
 const db::Text *

src/db/db/dbRecursiveShapeIterator.cc

@@ -598,6 +598,13 @@ RecursiveShapeIterator::at_end () const
   return m_shape.at_end () || is_inactive ();
 }
 
+bool
+RecursiveShapeIterator::at_end_no_lock () const
+{
+  RecursiveShapeIterator copy (*this);
+  return copy.at_end ();
+}
+
 std::vector<db::InstElement>
 RecursiveShapeIterator::path () const
 {

src/db/db/dbRecursiveShapeIterator.h

@@ -709,6 +709,16 @@ public:
    */
   bool at_end () const;
 
+  /**
+   *  @brief End of iterator predicate
+   *
+   *  Returns true, if the iterator is at the end of the sequence
+   *
+   *  This version does not lock the layout and can be used after initialization
+   *  to detect empty sequences.
+   */
+  bool at_end_no_lock () const;
+
   /**
    *  @brief Gets the translated property ID
    *

src/db/db/dbTilingProcessor.cc

@@ -876,7 +876,7 @@ TilingProcessor::execute (const std::string &desc)
 
   if (tot_box.empty ()) {
     for (std::vector<InputSpec>::const_iterator i = m_inputs.begin (); i != m_inputs.end (); ++i) {
-      if (! i->iter.at_end ()) {
+      if (! i->iter.at_end_no_lock ()) {
         if (scale_to_dbu ()) {
           double dbu_value = i->iter.layout () ? i->iter.layout ()->dbu () : dbu ();
           tot_box += i->iter.bbox ().transformed (db::CplxTrans (dbu_value) * db::CplxTrans (i->trans));

src/db/unit_tests/dbTilingProcessorTests.cc

@@ -148,7 +148,9 @@ TEST(2)
     tp.queue ("_output(o1, _tile ? (i1 & i2 & _tile) : (i1 & i2), false)");
     tp.queue ("!_tile && _output(o2, i1.outside(i2), false)");
     tp.queue ("_tile && _output(o3, _tile, false)");
+    EXPECT_EQ (ly.under_construction (), false);
     tp.execute ("test");
+    EXPECT_EQ (ly.under_construction (), false);
 
     EXPECT_EQ (to_s (ly, top, o1), "box (60,10;70,20);box (10,10;30,30)");
     EXPECT_EQ (to_s (ly, top, o2), "box (50,40;80,70)");

src/drc/drc/built-in-macros/_drc_layer.rb

@@ -4624,6 +4624,8 @@ TP_SCRIPT
         res
       end
 
+      tp._destroy
+
       DRCLayer::new(@engine, res)
 
     end