From 42c981c6b53e8474a41b053247d90dcb6059b850 Mon Sep 17 00:00:00 2001
From: Sebastian Buchwald <Sebastian.Buchwald@kit.edu>
Date: Mon, 6 Oct 2008 11:52:47 +0000
Subject: [PATCH] Bugfix: handle added edges correctly if src_index and
 tgt_index are in the wrong order.

[r22527]
---
 kaps.c   |  6 ++++++
 matrix.c | 14 ++++++++++++++
 matrix.h |  2 ++
 3 files changed, 22 insertions(+)

diff --git a/kaps.c b/kaps.c
index 346046023..577649362 100644
--- a/kaps.c
+++ b/kaps.c
@@ -80,6 +80,12 @@ void add_edge_costs(pbqp *pbqp, unsigned src_index, unsigned tgt_index,
 {
 	pbqp_edge *edge = get_edge(pbqp, src_index, tgt_index);
 
+	if (tgt_index < src_index) {
+		pbqp_matrix_transpose(pbqp, costs);
+		add_edge_costs(pbqp, tgt_index, src_index, costs);
+		return;
+	}
+
 	if (edge == NULL) {
 		edge = alloc_edge(pbqp, src_index, tgt_index, costs);
 	} else {
diff --git a/matrix.c b/matrix.c
index 43dda121d..8ff873cdd 100644
--- a/matrix.c
+++ b/matrix.c
@@ -52,6 +52,20 @@ pbqp_matrix *pbqp_matrix_copy_and_transpose(pbqp *pbqp, pbqp_matrix *m)
 	return copy;
 }
 
+void pbqp_matrix_transpose(pbqp *pbqp, pbqp_matrix *mat)
+{
+	unsigned len;
+
+	assert(mat);
+	len = mat->rows * mat->cols;
+
+	pbqp_matrix *tmp = pbqp_matrix_copy_and_transpose(pbqp, mat);
+
+	memcpy(mat, tmp, sizeof(*mat) + sizeof(*mat->entries) * len);
+
+	obstack_free(&pbqp->obstack, tmp);
+}
+
 void pbqp_matrix_add(pbqp_matrix *sum, pbqp_matrix *summand)
 {
 	int i;
diff --git a/matrix.h b/matrix.h
index 0d45a1514..90fe7cee4 100644
--- a/matrix.h
+++ b/matrix.h
@@ -10,6 +10,8 @@ pbqp_matrix *pbqp_matrix_copy(pbqp *pbqp, pbqp_matrix *m);
 
 pbqp_matrix *pbqp_matrix_copy_and_transpose(pbqp *pbqp, pbqp_matrix *m);
 
+void pbqp_matrix_transpose(pbqp *pbqp, pbqp_matrix *mat);
+
 /* sum += summand */
 void pbqp_matrix_add(pbqp_matrix *sum, pbqp_matrix *summand);
 
-- 
2.20.1