IDEA-64713 Using a comma in code completion inserts a trailing space for method calls but not for variable names

java/java-impl/src/com/intellij/codeInsight/lookup/VariableLookupItem.java

@@ -37,5 +37,9 @@ public class VariableLookupItem extends LookupItem<PsiVariable> implements Typed
       context.setAddCompletionChar(false);
       TailType.EQ.processTail(context.getEditor(), context.getTailOffset());
     }
+    else if (context.getCompletionChar() == ',' && getAttribute(LookupItem.TAIL_TYPE_ATTR) != TailType.UNKNOWN) {
+      context.setAddCompletionChar(false);
+      TailType.COMMA.processTail(context.getEditor(), context.getTailOffset());
+    }
   }
 }

java/java-tests/testData/codeInsight/completion/normal/CommaAfterVariable.java

@@ -0,0 +1,10 @@
+class AbcdClass {}
+class AbcdException extends Throwable {}
+
+class Foo {
+  {
+    int aaa;
+    int aab;
+    equals(aa<caret>)
+  }
+}

java/java-tests/testData/codeInsight/completion/normal/CommaAfterVariable_after.java

@@ -0,0 +1,10 @@
+class AbcdClass {}
+class AbcdException extends Throwable {}
+
+class Foo {
+  {
+    int aaa;
+    int aab;
+    equals(aaa, <caret>)
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionTest.groovy

@@ -823,6 +823,8 @@ public class NormalCompletionTest extends LightFixtureCompletionTestCase {
   public void testOnlyAnnotationsAfterAt() throws Throwable { doTest() }
   public void testOnlyExceptionsInCatch() throws Throwable { doTest() }
 
+  public void testCommaAfterVariable() throws Throwable { doTest(',') }
+
   public void testSuperProtectedMethod() throws Throwable {
     myFixture.addClass """package foo;
       public class Bar {