[gimp/gimp-2-10] app: reset common settings when resetting Curves tool

[Ell <ell src gnome org>]

commit c2ee2553ce29736b31d3301b980cd49a624213c5
Author: Ell <ell_se yahoo com>
Date:   Tue Apr 14 17:53:21 2020 +0300

    app: reset common settings when resetting Curves tool
    
    In GimpCurveTool, don't reset the curve config manually, and rather
    let GimpFilterTool reset it, only maintaining the active channel
    (similarly to GimpLevelsTool), so that the common operation
    settings are also reset.
    
    Note that this also avoids keeping the channel curve types, which
    should work correctly after last commit.
    
    (cherry picked from commit 88689515ab22e973a32f53c73a857603090a8adc)

 app/tools/gimpcurvestool.c | 45 ++++++++-------------------------------------
 1 file changed, 8 insertions(+), 37 deletions(-)
---
diff --git a/app/tools/gimpcurvestool.c b/app/tools/gimpcurvestool.c
index 18d211f433..d514323a51 100644
--- a/app/tools/gimpcurvestool.c
+++ b/app/tools/gimpcurvestool.c
@@ -684,46 +684,17 @@ gimp_curves_tool_dialog (GimpFilterTool *filter_tool)
 static void
 gimp_curves_tool_reset (GimpFilterTool *filter_tool)
 {
-  GimpCurvesConfig     *config = GIMP_CURVES_CONFIG (filter_tool->config);
-  GimpCurvesConfig     *default_config;
-  GimpHistogramChannel  channel;
-
-  default_config = GIMP_CURVES_CONFIG (filter_tool->default_config);
-
-  g_object_freeze_notify (G_OBJECT (config));
-
-  if (default_config)
-    g_object_set (config, "linear", default_config->linear, NULL);
-  else
-    gimp_config_reset_property (G_OBJECT (config), "linear");
-
-  for (channel = GIMP_HISTOGRAM_VALUE;
-       channel <= GIMP_HISTOGRAM_ALPHA;
-       channel++)
-    {
-      if (default_config)
-        {
-          GimpCurveType curve_type = config->curve[channel]->curve_type;
-
-          g_object_freeze_notify (G_OBJECT (config->curve[channel]));
-
-          gimp_config_copy (GIMP_CONFIG (default_config->curve[channel]),
-                            GIMP_CONFIG (config->curve[channel]),
-                            0);
+  GimpHistogramChannel channel;
 
-          g_object_set (config->curve[channel],
-                        "curve-type", curve_type,
-                        NULL);
+  g_object_get (filter_tool->config,
+                "channel", &channel,
+                NULL);
 
-          g_object_thaw_notify (G_OBJECT (config->curve[channel]));
-        }
-      else
-        {
-          gimp_curve_reset (config->curve[channel], FALSE);
-        }
-    }
+  GIMP_FILTER_TOOL_CLASS (parent_class)->reset (filter_tool);
 
-  g_object_thaw_notify (G_OBJECT (config));
+  g_object_set (filter_tool->config,
+                "channel", channel,
+                NULL);
 }
 
 static void