Postpone decision about "invalid vias are errors."

src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.cc

@@ -749,7 +749,12 @@ DEFImporter::read_single_net (std::string &nondefaultrule, Layout &layout, db::C
         }
 
         std::map<std::string, ViaDesc>::const_iterator vd = m_via_desc.find (vn);
-        if (vd != m_via_desc.end () && ! pts.empty ()) {
+
+        if (vd == m_via_desc.end ()) {
+
+          warn (tl::to_string (tr ("Invalid via name: ")) + vn);
+
+        } else if (! pts.empty ()) {
 
           //  For the via, the masks are encoded in a three-digit number (<mask-top> <mask-cut> <mask_bottom>)
           unsigned int mask_top = (mask / 100) % 10;

src/plugins/streamers/lefdef/unit_tests/dbLEFDEFImportTests.cc

@@ -898,6 +898,21 @@ TEST(132_issue1307_pin_names)
   run_test (_this, "issue-1307c", "lef:in.lef+def:in.def", "au.oas", opt, false);
 }
 
+/*
+TODO: need to clarify first, if invalid via specs should be errors
+TEST(133_unknown_vias_are_errors)
+{
+  db::LEFDEFReaderOptions opt = default_options ();
+
+  try {
+    run_test (_this, "invalid_via", "lef:tech.lef+def:comp_invalid_via.def", "au.oas", opt, false);
+    EXPECT_EQ (true, false);
+  } catch (db::LEFDEFReaderException &ex) {
+    EXPECT_EQ (ex.msg ().find ("Invalid via name"), size_t (0));
+  }
+}
+*/
+
 TEST(200_lefdef_plugin)
 {
   db::Layout ly;