From 3934b77f6490d789063dc05853035a7d37fc44ca Mon Sep 17 00:00:00 2001
From: "R. Timothy Edwards" <tim@opencircuitdesign.com>
Date: Mon, 8 Jun 2026 15:58:06 -0400
Subject: [PATCH] Modified the GDS path handling so that duplicate points
 produce a warning appropriate for duplicate points and not a path reversal
 warning.  Modified the output for path reversal or duplicate point errors so
 that the coordinate is in GDS units and not path units (which are multiplied
 by 2).

---
 calma/CalmaRdpt.c |  1 -
 cif/CIFrdpt.c     | 17 +++++++++++++++--
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/calma/CalmaRdpt.c b/calma/CalmaRdpt.c
index 767b2a90..7776bc64 100644
--- a/calma/CalmaRdpt.c
+++ b/calma/CalmaRdpt.c
@@ -537,7 +537,6 @@ calmaElementPath(void)
     int layer, dt, width, pathtype, ciftype, savescale;
     int xmin, ymin, xmax, ymax, temp;
     CIFPath *pathheadp, *pathp, *previousp;
-    Rect segment;
     Plane *plane;
     int first,last;
     CellUse *use;
diff --git a/cif/CIFrdpt.c b/cif/CIFrdpt.c
index dee267d9..6ed09889 100644
--- a/cif/CIFrdpt.c
+++ b/cif/CIFrdpt.c
@@ -462,9 +462,22 @@ CIFPaintWirePath(
 		/* Wire reverses direction.  Break wire here,	*/
 		/* draw, and start new polygon.			*/
 
-		TxError("Warning: direction reversal in path at (%d, %d).\n",
-				pathp->cifp_x, pathp->cifp_y);
+		/* Check first if last point and current point	*/
+		/* are the same, in which case a different	*/
+		/* message should be issued (and possibly	*/
+		/* should be handled differently?)		*/
 
+		if (previousp && previousp->cifp_x == pathp->cifp_x
+			&& previousp->cifp_y == pathp->cifp_y)
+		{
+		    TxError("Warning: duplicate point in path at (%d, %d).\n",
+				pathp->cifp_x / 2, pathp->cifp_y / 2);
+		}
+		else
+		{
+		    TxError("Warning: direction reversal in path at (%d, %d).\n",
+				pathp->cifp_x / 2, pathp->cifp_y / 2);
+		}
 		phi = theta;
 		if (endcap)
 		{