From 8fc2c097d2bb5ac3020498b1a9ac06df4a1d4bd5 Mon Sep 17 00:00:00 2001
From: Tim Edwards <tim@opencircuitdesign.com>
Date: Tue, 25 May 2021 12:41:57 -0400
Subject: [PATCH] Added one modification that automatically ignores any cell
 that has no pins at all.  This overrides the default behavior of treating
 empty cells as "black-box" entries, and avoids attempts to compare cells like
 logo artwork.

---
 VERSION       | 2 +-
 base/netgen.c | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/VERSION b/VERSION
index d50ff44..2af461c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.178
+1.5.179
diff --git a/base/netgen.c b/base/netgen.c
index ae57791..18890d3 100644
--- a/base/netgen.c
+++ b/base/netgen.c
@@ -1593,6 +1593,12 @@ char *Cell(char *inststr, char *model, ...)
     if (IsPort(tp2)) portnum++;
     tp2 = tp2->next;
   }
+
+  /* Automatically ignore any cell that has no ports (e.g., logo art) */
+  if (portnum == 0) {
+    Printf("Class '%s' has no pins and so will be ignored.\n", model);
+    return NULL;
+  }
 	
   /* now generate lists of nodes using variable length parameter list */
   va_start(ap, model);