choosing the default values bit more wisely

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@4569 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/Functions.java

@@ -608,4 +608,14 @@ public class Functions {
     public static String getResourcePath() {
         return Hudson.RESOURCE_PATH;
     }
+
+    /**
+     * Can be used to check a checkbox by default.
+     * Used from views like {@code h.defaultToTrue(scm.useUpdate)}.
+     * The expression will evaluate to true if scm is null.
+     */
+    public static boolean defaultToTrue(Boolean b) {
+        if(b==null) return true;
+        return b;
+    }
 }

core/src/main/resources/hudson/scm/CVSSCM/config.jelly

@@ -16,7 +16,7 @@
 	  <f:textbox name="cvs.cvsRsh" value="${scm.cvsRsh}"/>
 	</f:entry>
 	<f:entry title="Use update" help="/help/_cvs/update.html">
-	  <f:checkbox name="cvs.canUseUpdate" checked="${scm.canUseUpdate}"/>
+	  <f:checkbox name="cvs.canUseUpdate" checked="${h.defaultToTrue(scm.canUseUpdate)}"/>
 	</f:entry>
 	<f:entry title="Legacy mode" help="/help/_cvs/legacy.html">
 	  <f:checkbox name="cvs.legacy" checked="${scm!=null and !scm.flatten}"/>

core/src/main/resources/hudson/scm/SubversionSCM/config.jelly

@@ -23,7 +23,7 @@
     description="
       If checked, Hudson will use 'svn update' whenever possible, making the build faster.
       But this causes the artifacts from the previous build to remain when a new build starts.">
-    <f:checkbox name="svn_use_update" checked="${scm.useUpdate}"/>
+    <f:checkbox name="svn_use_update" checked="${h.defaultToTrue(scm.useUpdate)}"/>
   </f:entry>
 
   <t:listScmBrowsers name="svn.browser" />