IDEA-90349 Auto-completion should always prefer exact match

java/java-tests/testData/codeInsight/completion/normalSorting/PreferFieldToMethod.java

@@ -0,0 +1,6 @@
+public class Foo {
+  private int size;
+
+  public int size() { return size; }
+
+  public boolean isEmpty() { return size<caret>

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

@@ -12,6 +12,7 @@ import com.intellij.codeInsight.lookup.LookupElementPresentation
 import com.intellij.codeInsight.lookup.impl.LookupImpl
 import com.intellij.ide.ui.UISettings
 import com.intellij.psi.PsiClass
+import com.intellij.psi.PsiField
 import com.intellij.psi.PsiMethod
 import com.intellij.openapi.fileEditor.FileDocumentManager
 import com.intellij.psi.statistics.StatisticsManager
@@ -446,4 +447,10 @@ import java.lang.annotation.Target;
     assertPreferredItems(0, '_goo2', '_goo1')
   }
 
+  public void testPreferFieldToMethod() {
+    checkPreferredItems(0, 'size', 'size')
+    assert lookup.items[0].object instanceof PsiField
+    assert lookup.items[1].object instanceof PsiMethod
+  }
+
 }

platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionLookupArranger.java

@@ -144,10 +144,16 @@ public class CompletionLookupArranger extends LookupArranger {
     }
     classifier.addElement(element);
 
-    final String invariant = presentation.getItemText() + "###" + presentation.getTailText() + "###" + presentation.getTypeText();
+    final String invariant = presentation.getItemText() + "###" + getTailTextOrSpace(presentation) + "###" + presentation.getTypeText();
     element.putUserData(PRESENTATION_INVARIANT, invariant);
   }
 
+  @NotNull
+  private static String getTailTextOrSpace(LookupElementPresentation presentation) {
+    String tailText = presentation.getTailText();
+    return tailText == null || tailText.isEmpty() ? " " : tailText;
+  }
+
   private static List<LookupElement> sortByPresentation(Iterable<LookupElement> source) {
     ArrayList<LookupElement> result = ContainerUtil.newArrayList(source);
     ContainerUtil.sort(result, new Comparator<LookupElement>() {