allow a button to be marked as 'download', which causes it to be hidden when patch is available

platform/platform-impl/src/com/intellij/openapi/updateSettings/impl/ButtonInfo.java

@@ -23,10 +23,12 @@ import org.jdom.Element;
 public class ButtonInfo {
   private final String myName;
   private final String myUrl;
+  private final boolean myDownload;
 
   public ButtonInfo(Element element) {
     myName = element.getAttributeValue("name");
     myUrl = element.getAttributeValue("url");
+    myDownload = element.getAttributeValue("download") != null;
   }
 
   public String getName() {
@@ -36,4 +38,13 @@ public class ButtonInfo {
   public String getUrl() {
     return myUrl;
   }
+
+  /**
+   * The button marked with 'download=true' attribute is hidden if patch is available.
+   *
+   * @return true if the button should be hidden when the patch is available.
+   */
+  public boolean isDownload() {
+    return myDownload;
+  }
 }

platform/platform-impl/src/com/intellij/openapi/updateSettings/impl/UpdateInfoDialog.java

@@ -66,11 +66,14 @@ class UpdateInfoDialog extends AbstractUpdateDialog {
       }
       else {
         for (ButtonInfo info : buttons) {
-          actions.add(new ButtonAction(info));
+          if (!info.isDownload()) {
+            actions.add(new ButtonAction(info));
+          }
         }
       }
     }
     else {
+      // the first button replaces the OK action
       for (int i = 1; i < buttons.size(); i++) {
         actions.add(new ButtonAction(buttons.get(i)));
       }