Java: fix Extend Selection on empty text block (IDEA-372040)

GitOrigin-RevId: a47f4128f616b8b4921b81708daaa1839f0fa3f2

java/java-frontback-impl/src/com/intellij/codeInsight/editorActions/wordSelection/LiteralSelectioner.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.codeInsight.editorActions.wordSelection;
 
 import com.intellij.codeInsight.editorActions.SelectWordUtil;
@@ -72,12 +72,12 @@ public final class LiteralSelectioner extends AbstractBasicBackBasicSelectioner
         for (; end >= start; end--) {
           char c = text.charAt(end);
           if (c == '\n' || !Character.isWhitespace(c)) {
-            end += 1;
+            end++;
             break;
           }
         }
       }
-      return new TextRange(start, end);
+      return end < start ? range : new TextRange(start, end);
     }
     else {
       throw new IllegalArgumentException();

java/java-frontback-tests/testSrc/com/intellij/codeInsight/AbstractBasicJavaSelectWordTest.java

@@ -94,6 +94,7 @@ public abstract class AbstractBasicJavaSelectWordTest extends SelectWordTestBase
   public void testTextBlockEscapedLineEndings() { doTest("java"); }
   public void testTextBlockLeadingWhitespace() { doTest("java"); }
   public void testUnclosedTextBlock() { doTest("java"); }
+  public void testEmptyTextBlock() { doTest("java"); }
   public void testUnclosedLiteral() { doTest("java"); }
 
   public void testStringTemplate1() { doTest("java"); }

java/java-tests/testData/codeInsight/selectWordAction/emptyTextBlock/after1.java

@@ -0,0 +1,4 @@
+class X {{
+  String s = <selection>"<caret>""
+    """</selection>;
+}}

java/java-tests/testData/codeInsight/selectWordAction/emptyTextBlock/after2.java

@@ -0,0 +1,4 @@
+class X {{
+<selection>  String s = "<caret>""
+    """;
+</selection>}}

java/java-tests/testData/codeInsight/selectWordAction/emptyTextBlock/before.java

@@ -0,0 +1,4 @@
+class X {{
+  String s = "<caret>""
+    """;
+}}