change signature: process first param spacing (IDEA-59817)

java/java-impl/src/com/intellij/psi/impl/source/tree/java/ParameterListElement.java

@@ -77,7 +77,8 @@ public class ParameterListElement extends CompositeElement implements Constants
   }
 
   public void deleteChildInternal(@NotNull ASTNode child) {
-    TreeElement oldLastNodeInsideParens = getLastNodeInsideParens();
+    final TreeElement oldLastNodeInsideParens = getLastNodeInsideParens();
+    final TreeElement oldFirstNodeInsideParens = getFirstNodeInsideParens();
     if (child.getElementType() == PARAMETER) {
       ASTNode next = TreeUtil.skipElements(child.getTreeNext(), StdTokenSets.WHITE_SPACE_OR_COMMENT_BIT_SET);
       if (next != null && next.getElementType() == COMMA) {
@@ -105,6 +106,15 @@ public class ParameterListElement extends CompositeElement implements Constants
       }
     }
 
+    final TreeElement newFirstNodeInsideParens = getFirstNodeInsideParens();
+    if (newFirstNodeInsideParens != null && newFirstNodeInsideParens.getElementType() == WHITE_SPACE) {
+      if (oldFirstNodeInsideParens == null || oldFirstNodeInsideParens.getElementType() != WHITE_SPACE) {
+        deleteChildInternal(newFirstNodeInsideParens);
+      } else {
+        replaceChild(newFirstNodeInsideParens, (ASTNode)oldFirstNodeInsideParens.clone());
+      }
+    }
+
     //todo[max] hack?
     try {
       CodeStyleManager.getInstance(getManager().getProject()).reformat(getPsi());
@@ -166,4 +176,13 @@ public class ParameterListElement extends CompositeElement implements Constants
     TreeElement lastNode = getLastChildNode();
     return lastNode.getElementType() == RPARENTH ? lastNode.getTreePrev() : null;
   }
+
+   /**
+   * @return    first node after opening left paren if possible; <code>null</code> otherwise
+   */
+  @Nullable
+  private TreeElement getFirstNodeInsideParens() {
+    TreeElement firstNode = getFirstChildNode();
+    return firstNode.getElementType() == LPARENTH ? firstNode.getTreeNext() : null;
+  }
 }

java/java-tests/testData/refactoring/changeSignature/RemoveFirstParameter.java

@@ -0,0 +1,5 @@
+class Test {
+    void <caret>foo(boolean b,
+             int i) { // Don't expect line break to be inserted before closing method args bracket
+    }
+}

java/java-tests/testData/refactoring/changeSignature/RemoveFirstParameter_after.java

@@ -0,0 +1,4 @@
+class Test {
+    void <caret>foo(int i) { // Don't expect line break to be inserted before closing method args bracket
+    }
+}

java/java-tests/testSrc/com/intellij/refactoring/ChangeSignatureTest.java

@@ -224,6 +224,10 @@ public class ChangeSignatureTest extends LightCodeInsightTestCase {
     doTest(null, new ParameterInfoImpl[] {new ParameterInfoImpl(1), new ParameterInfoImpl(0)}, false);
   }
 
+  public void testRemoveFirstParameter() throws Exception {
+    doTest(null, new ParameterInfoImpl[]{new ParameterInfoImpl(1)}, false);
+  }
+
   public void testReplaceVarargWithArray() throws Exception {
     doTest(null, null, null, new GenParams() {
       @Override