From 4166408576d46acfe90878ac98d7c29f24abb206 Mon Sep 17 00:00:00 2001
From: Tim Edwards <tim@opencircuitdesign.com>
Date: Thu, 5 Apr 2018 10:06:32 -0400
Subject: [PATCH] Discovered a subtle error caused by running a setup script
 that calls "equate pins".  This could fail because the routine that forces
 uniqueness of pins was being called by the "compare" command but outside of
 PinMatch.  Fixed by duplicating the call to force uniqueness of pins inside
 the "equate" function.  Redundant calls should not matter as uniqueness is
 resolved on the first call and subsequent calls will need no further action.

---
 base/netcmp.c     |  8 ++++++--
 tcltk/tclnetgen.c | 17 ++++++++++++++---
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/base/netcmp.c b/base/netcmp.c
index 496d9af..55f70ff 100644
--- a/base/netcmp.c
+++ b/base/netcmp.c
@@ -6393,9 +6393,13 @@ struct nlist *addproxies(struct hashlist *p, void *clientdata)
 /* circuit pair has been matched with automorphisms,	*/
 /* then some pins may be matched arbitrarily.		*/
 /*							*/
-/* Return 1 on success, 0 on failure.			*/
 /* If "dolist" is 1, append the list representing the	*/
 /* output (if any) to variable tcl_out, if it exists.	*/
+/*							*/
+/* Return codes:					*/
+/* 2: Neither cell had pins, so matching is unnecessary	*/
+/* 1: Exact match					*/
+/* 0: Inexact match resolved by proxy pin insertion	*/
 /*------------------------------------------------------*/
 
 int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
@@ -6432,7 +6436,7 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
    if (haspins == 0) {
       // Neither cell has any ports, so this is probably a top-level
       // cell and there is nothing to do.
-      return 1;
+      return 2;
    }
 
    cover = (char *)CALLOC(numnodes, sizeof(char));
diff --git a/tcltk/tclnetgen.c b/tcltk/tclnetgen.c
index 242aee6..94d04fd 100644
--- a/tcltk/tclnetgen.c
+++ b/tcltk/tclnetgen.c
@@ -2910,15 +2910,26 @@ _netcmp_equate(ClientData clientData,
 	    Circuit1 = tp1;
 	    Circuit2 = tp2;
 	 }
-	 if (MatchPins(tp1, tp2, dolist)) {
+
+	 // Check for and remove duplicate pins.  Normally this is called
+	 // from "compare", but since "equate pins" may be called outside
+	 // of and before "compare", pin uniqueness needs to be ensured.
+
+	 UniquePins(tp1->name, tp1->file);
+	 UniquePins(tp2->name, tp2->file);
+
+	 result = MatchPins(tp1, tp2, dolist);
+	 if (result == 2) {
+	    Fprintf(stdout, "Cells have no pins;  pin matching not needed.\n");
+	 }
+	 else if (result > 0) {
 	    Fprintf(stdout, "Cell pin lists are equivalent.\n");
-	    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(1));
 	 }
 	 else {
 	    Fprintf(stdout, "Cell pin lists for %s and %s altered to match.\n",
 			name1, name2);
-	    Tcl_SetObjResult(interp, Tcl_NewBooleanObj(0));
 	 }
+	 Tcl_SetObjResult(interp, Tcl_NewIntObj(result));
 	 if (ElementClasses == NULL) {
 	    /* Recover temporarily set global variables (see above) */
 	    Circuit1 = SaveC1;