Set inland water bodies icing when the icing slider >= 0.05

Environment/environment.xml

@@ -486,6 +486,7 @@
     <wetness-set type="double" userarchive="y">0.0</wetness-set>
     <wetness type="double" userarchive="n">0.0</wetness>
     <snow-thickness-factor type="double" userarchive="y">1.0</snow-thickness-factor>
+    <ice-cover type="bool" userarchive="n">false</ice-cover>
     <delta-T-soil type="double" userarchive="n">0.0</delta-T-soil>
     <delta-T-vegetation type="double" userarchive="n">0.0</delta-T-vegetation>
     <delta-T-rock type="double" userarchive="n">0.0</delta-T-rock>

Materials/default/global-summer.xml

@@ -279,6 +279,9 @@
   <name>Watercourse</name>
   <name>Saline</name>
   <texture>Terrain/water-lake.png</texture>
+  <parameters>
+    <ice_cover><use>/environment/surface/ice-cover</use></ice_cover>
+  </parameters>
   <xsize>400</xsize>
   <ysize>400</ysize>
   <ambient>
@@ -300,7 +303,7 @@
    <a>1.0</a>
   </specular>
   <shininess>1.2</shininess>
-  <solid>0</solid>
+  <solid><property>/environment/surface/ice-cover</property></solid>
   <rolling-friction>1.5</rolling-friction>
   <bumpiness>0.6</bumpiness>
 </material>

Materials/regions/global-summer.xml

@@ -432,6 +432,9 @@
     <name>Watercourse</name>
     <name>Saline</name>
     <texture>Terrain/water-lake.png</texture>
+    <parameters>
+      <ice_cover><use>/environment/surface/ice-cover</use></ice_cover>
+    </parameters>
     <xsize>400</xsize>
     <ysize>400</ysize>
     <ambient>
@@ -453,7 +456,7 @@
       <a>1.0</a>
     </specular>
     <shininess>1.2</shininess>
-    <solid>0</solid>
+    <solid><property>/environment/surface/ice-cover</property></solid>
     <rolling-friction>1.5</rolling-friction>
     <bumpiness>0.6</bumpiness>
   </material>

gui/dialogs/environment-settings.xml

@@ -64,7 +64,7 @@
         </binding>
         <binding>
           <command>property-toggle</command>
-      </binding>
+        </binding>
       </checkbox>
 
       <checkbox>
@@ -210,6 +210,18 @@
        <command>dialog-apply</command>
        <object-name>ice-cover</object-name>
      </binding>
+     <binding>
+       <command>nasal</command>
+       <script>
+         <![CDATA[
+          if (getprop( "/environment/sea/surface/ice-cover" ) < 0.05 ) {
+            setprop( "/environment/surface/ice-cover", 0 );
+          } else {
+            setprop( "/environment/surface/ice-cover", 1 );
+          }
+        ]]>
+       </script>
+     </binding>
     </slider>
 
     <text>