IDEA-88106 Auto-completion works incorrectly when I make and then fix a mistake

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

@@ -1272,4 +1272,22 @@ class Foo {
     myFixture.checkResult 'class Foo {{ boolean <caret> }}'
   }
 
+  @Override
+  protected void tearDown() {
+    CodeInsightSettings.instance.COMPLETION_CASE_SENSITIVE = CodeInsightSettings.FIRST_LETTER
+    super.tearDown()
+  }
+
+  public void testBackspaceShouldShowPreviousVariants() {
+    CodeInsightSettings.instance.COMPLETION_CASE_SENSITIVE = CodeInsightSettings.NONE
+    myFixture.addClass("class OuterX { static class TrueLine {} }")
+    myFixture.configureByText 'a.java', 'class Foo{ void foo(int truex) { return tr<caret> }}'
+    type 'ue'
+    assert myFixture.lookupElementStrings == ['true', 'truex']
+    type 'l'
+    assert myFixture.lookupElementStrings == ['TrueLine']
+    type '\b'
+    assert myFixture.lookupElementStrings == ['true', 'truex']
+  }
+
 }

java/testFramework/src/com/intellij/codeInsight/completion/CompletionTestCase.java

@@ -63,7 +63,7 @@ public abstract class CompletionTestCase extends DaemonAnalyzerTestCase {
   }
 
   protected void complete(final int time) {
-    new CodeCompletionHandlerBase(myType).invokeCompletion(myProject, myEditor, time, false);
+    new CodeCompletionHandlerBase(myType).invokeCompletion(myProject, myEditor, time);
 
     LookupImpl lookup = (LookupImpl)LookupManager.getActiveLookup(myEditor);
     myItems = lookup == null ? null : lookup.getItems().toArray(new LookupElement[lookup.getItems().size()]);

java/testFramework/src/com/intellij/codeInsight/completion/LightCompletionTestCase.java

@@ -57,7 +57,7 @@ public abstract class LightCompletionTestCase extends LightCodeInsightTestCase {
   }
 
   protected void complete(final int time) {
-    new CodeCompletionHandlerBase(myType).invokeCompletion(getProject(), getEditor(), time, false);
+    new CodeCompletionHandlerBase(myType).invokeCompletion(getProject(), getEditor(), time);
 
     LookupImpl lookup = (LookupImpl)LookupManager.getActiveLookup(myEditor);
     myItems = lookup == null ? null : lookup.getItems().toArray(LookupElement.EMPTY_ARRAY);