From d65148ed0bfb648f5198f6190e058387357f6dad Mon Sep 17 00:00:00 2001
From: Matthias Koefferlein <matthias@koefferlein.de>
Date: Sun, 27 Jun 2021 17:29:41 +0200
Subject: [PATCH] Fixed #846

---
 src/db/db/dbNetlistCrossReference.cc            | 10 ++++++++--
 src/laybasic/laybasic/layNetlistBrowserModel.cc | 12 ++++++------
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/db/db/dbNetlistCrossReference.cc b/src/db/db/dbNetlistCrossReference.cc
index 4ebae1072..99ab8c780 100644
--- a/src/db/db/dbNetlistCrossReference.cc
+++ b/src/db/db/dbNetlistCrossReference.cc
@@ -113,6 +113,10 @@ NetlistCrossReference::other_net_for (const db::Net *net) const
 const NetlistCrossReference::PerNetData *
 NetlistCrossReference::per_net_data_for (const std::pair<const db::Net *, const db::Net *> &nets) const
 {
+  if (! nets.first && ! nets.second) {
+    return 0;
+  }
+
   std::map<std::pair<const db::Net *, const db::Net *>, PerNetData>::iterator i = m_per_net_data.find (nets);
   if (i == m_per_net_data.end ()) {
     i = m_per_net_data.insert (std::make_pair (nets, PerNetData ())).first;
@@ -628,11 +632,13 @@ NetlistCrossReference::build_subcircuit_pin_refs (const std::pair<const db::Net
 void
 NetlistCrossReference::build_per_net_info (const std::pair<const db::Net *, const db::Net *> &nets, PerNetData &data) const
 {
-  if (! nets.second) {
+  if (! nets.first && ! nets.second) {
+    //  .. nothing ..
+  } else if (! nets.second) {
     init_data_from_single (nets.first, data, true);
   } else if (! nets.first) {
     init_data_from_single (nets.second, data, false);
-  } else if (nets.first) {
+  } else {
     build_terminal_refs (nets, data);
     build_pin_refs (nets, data);
     build_subcircuit_pin_refs (nets, data);
diff --git a/src/laybasic/laybasic/layNetlistBrowserModel.cc b/src/laybasic/laybasic/layNetlistBrowserModel.cc
index b160ac73a..5def404a6 100644
--- a/src/laybasic/laybasic/layNetlistBrowserModel.cc
+++ b/src/laybasic/laybasic/layNetlistBrowserModel.cc
@@ -233,11 +233,11 @@ static QString escaped (const std::string &s)
 }
 
 template <class Obj>
-static std::string str_from_expanded_name (const Obj *obj, bool dash_for_empty = false)
+static std::string str_from_expanded_name (const Obj *obj, bool indicate_empty = false)
 {
   if (obj) {
     return obj->expanded_name ();
-  } else if (dash_for_empty) {
+  } else if (indicate_empty) {
     return std::string ("-");
   } else {
     return std::string ();
@@ -245,11 +245,11 @@ static std::string str_from_expanded_name (const Obj *obj, bool dash_for_empty =
 }
 
 template <class Obj>
-static std::string str_from_name (const Obj *obj, bool dash_for_empty = false)
+static std::string str_from_name (const Obj *obj, bool indicate_empty = false)
 {
   if (obj) {
     return obj->name ();
-  } else if (dash_for_empty) {
+  } else if (indicate_empty) {
     return std::string ("-");
   } else {
     return std::string ();
@@ -264,7 +264,7 @@ static std::string str_from_expanded_names (const std::pair<const Obj *, const O
   std::string s = str_from_expanded_name (objs.first, ! is_single);
   if (! is_single) {
     std::string t = str_from_expanded_name (objs.second, ! is_single);
-    if (t != s) {
+    if (t != s || ! objs.first || ! objs.second) {
       s += var_sep;
       s += t;
     }
@@ -278,7 +278,7 @@ static std::string str_from_names (const std::pair<const Obj *, const Obj *> &ob
   std::string s = str_from_name (objs.first, ! is_single);
   if (! is_single) {
     std::string t = str_from_name (objs.second, ! is_single);
-    if (t != s) {
+    if (t != s || ! objs.first || ! objs.second) {
       s += var_sep;
       s += t;
     }