[goffice] Fix backplane position when data are nearly all the same. [#684599]

[Jean BrÃfort <jbrefort src gnome org>]

commit 732c8a897ac85998a97363ef6472d54d92904df5
Author: Jean Brefort <jean brefort normalesup org>
Date:   Sun Sep 23 16:22:00 2012 +0200

    Fix backplane position when data are nearly all the same. [#684599]

 ChangeLog                |    5 +++++
 NEWS                     |    1 +
 goffice/graph/gog-axis.c |    2 ++
 3 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 0d83ec3..4f41acd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2012-09-23  Jean Brefort  <jean brefort normalesup org>
+
+	* goffice/graph/gog-axis.c (map_linear_auto_bound): fix scale when data
+	differ are nearly identical. [#684599]
+
 2012-09-20  Jean Brefort  <jean brefort normalesup org>
 
 	* plugins/plot_distrib/gog-histogram.c
diff --git a/NEWS b/NEWS
index db55bf2..b4952dd 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,7 @@ Jean:
 	* New scattered min-max plot type. [#683493]
 	* Don't crash when no valid data is available for histograms. [#684047]
 	* Clip histograms to the plot area. [#684195]
+	* Fix backplane position when data are nearly all the same. [#684599]
 
 --------------------------------------------------------------------------
 goffice 0.9.6:
diff --git a/goffice/graph/gog-axis.c b/goffice/graph/gog-axis.c
index 5871d7b..42e8d7c 100644
--- a/goffice/graph/gog-axis.c
+++ b/goffice/graph/gog-axis.c
@@ -722,6 +722,8 @@ map_linear_auto_bound (GogAxis *axis, double minimum, double maximum, double *bo
 	range = fabs (maximum - minimum);
 
 	/* handle singletons */
+	if (range > 0. && range / (fabs (minimum) + fabs (maximum)) <= DBL_EPSILON)
+		range = 0.;
 	if (go_sub_epsilon (range) <= 0.) {
 		if (maximum > 0)
 			minimum = 0.;