Do not allow to create alias with invalid name (IDEA-154452)

platform/lang-impl/src/com/intellij/application/options/codeStyle/arrangement/match/tokens/ArrangementRuleAliasesListEditor.java

@@ -17,17 +17,22 @@ package com.intellij.application.options.codeStyle.arrangement.match.tokens;
 
 import com.intellij.application.options.codeStyle.arrangement.color.ArrangementColorsProvider;
 import com.intellij.openapi.options.UnnamedConfigurable;
+import com.intellij.openapi.ui.InputValidator;
+import com.intellij.openapi.ui.Messages;
 import com.intellij.openapi.ui.NamedItemsListEditor;
 import com.intellij.openapi.ui.Namer;
 import com.intellij.openapi.util.Cloner;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.Factory;
-import com.intellij.psi.codeStyle.arrangement.std.StdArrangementRuleAliasToken;
 import com.intellij.psi.codeStyle.arrangement.std.ArrangementStandardSettingsManager;
+import com.intellij.psi.codeStyle.arrangement.std.StdArrangementRuleAliasToken;
 import gnu.trove.Equality;
+import org.jdom.Verifier;
 import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
+import java.text.MessageFormat;
 import java.util.List;
 import java.util.Set;
 
@@ -106,4 +111,21 @@ public class ArrangementRuleAliasesListEditor extends NamedItemsListEditor<StdAr
   public String getDisplayName() {
     return "Custom Composite Tokens";
   }
+
+  @Nullable
+  @Override
+  public String askForProfileName(String titlePattern) {
+    String title = MessageFormat.format(titlePattern, subjDisplayName());
+    return Messages.showInputDialog("New " + subjDisplayName() + " name:", title, Messages.getQuestionIcon(), "", new InputValidator() {
+      @Override
+      public boolean checkInput(String s) {
+        return s.length() > 0 && findByName(s) == null && Verifier.checkElementName(s) == null;
+      }
+
+      @Override
+      public boolean canClose(String s) {
+        return checkInput(s);
+      }
+    });
+  }
 }

platform/platform-api/src/com/intellij/openapi/ui/NamedItemsListEditor.java

@@ -122,7 +122,7 @@ public abstract class NamedItemsListEditor<T> extends MasterDetailsComponent {
     }
 
     @Nullable
-    private T findByName(String name) {
+    protected T findByName(String name) {
         for (T item : myItems) {
             if (Comparing.equal(name, myNamer.getName(item))) return item;
         }