[goffice] Regression: fix infinite loop.

[Morten Welinder <mortenw src gnome org>]

commit 4a125500cb19967e1bd2a7f1e1ea20bdae11a578
Author: Morten Welinder <terra gnome org>
Date:   Thu Feb 7 09:56:03 2013 -0500

    Regression: fix infinite loop.

 ChangeLog                    |    4 ++++
 goffice/math/go-regression.c |    2 +-
 2 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 3ad7478..2dfe234 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2013-02-07  Morten Welinder  <terra gnome org>
+
+	* goffice/math/go-regression.c (back_solve): Fix infinite loop.
+
 2013-01-30  Jean Brefort  <jean brefort normalesup org>
 
 	* goffice/graph/gog-axis.c (gog_axis_populate_editor): do not show the
diff --git a/goffice/math/go-regression.c b/goffice/math/go-regression.c
index f3f8dbd..9cb2c75 100644
--- a/goffice/math/go-regression.c
+++ b/goffice/math/go-regression.c
@@ -460,7 +460,7 @@ SUFFIX(back_solve) (CONSTQMATRIX R, QUAD *x, const QUAD *b, int n)
 			SUFFIX(go_quad_sub) (&d, &d, &p);
 		}
 		if (SUFFIX(go_quad_value)(&R[i][i]) == 0) {
-			while (i >= 0) SUFFIX(go_quad_init) (&x[i], 0);
+			while (i >= 0) SUFFIX(go_quad_init) (&x[i--], 0);
 			return TRUE;
 		}
 		SUFFIX(go_quad_div) (&x[i], &d, &R[i][i]);