don't suggest lowercase non-imported classes in autopopup (IDEA-114348)

java/java-impl/src/com/intellij/codeInsight/completion/AllClassesGetter.java

@@ -23,6 +23,8 @@ import com.intellij.openapi.editor.RangeMarker;
 import com.intellij.openapi.progress.ProgressManager;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Condition;
+import com.intellij.openapi.util.registry.Registry;
+import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
 import com.intellij.psi.impl.source.PostprocessReformattingAspect;
 import com.intellij.psi.impl.source.tree.java.PsiReferenceExpressionImpl;
@@ -156,8 +158,13 @@ public class AllClassesGetter {
 
       @Override
       public boolean process(PsiClass psiClass) {
-        if (parameters.getInvocationCount() < 2 && PsiReferenceExpressionImpl.seemsScrambled(psiClass)) {
-          return true;
+        if (parameters.getInvocationCount() < 2) {
+          if (PsiReferenceExpressionImpl.seemsScrambled(psiClass)) {
+            return true;
+          }
+          if (!StringUtil.isCapitalized(psiClass.getName()) && !Registry.is("ide.completion.show.lower.case.classes")) {
+            return true;
+          }
         }
 
         assert psiClass != null;

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

@@ -0,0 +1,6 @@
+public class Zoo {
+  void foo() {
+    abcdefg<caret>x
+  }
+
+}

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

@@ -1370,8 +1370,7 @@ class Foo {{
     myFixture.configureByText "a.java", """
 class Foo extends my<caret>
 """
-    myFixture.completeBasic()
-    myFixture.type('\n')
+    myFixture.complete(CompletionType.BASIC, 2)
     myFixture.checkResult '''import foo.myClass;
 
 class Foo extends myClass
@@ -1405,4 +1404,11 @@ class Bar {
 
   public void testNoMathTargetMethods() { doAntiTest() }
 
+  public void testNoLowercaseClasses() {
+    myFixture.addClass("package foo; public class abcdefgXxx {}")
+    doAntiTest()
+    myFixture.complete(CompletionType.BASIC, 2)
+    assertStringItems('abcdefgXxx')
+  }
+
 }

platform/platform-resources-en/src/misc/registry.properties

@@ -232,6 +232,10 @@ ide.completion.show.better.matching.classes=true
 # suppress inspection "UnusedProperty"
 ide.completion.show.better.matching.classes.description=Show non-imported but good matching classes in basic completion
 
+ide.completion.show.lower.case.classes=false
+# suppress inspection "UnusedProperty"
+ide.completion.show.lower.case.classes.description=Show non-imported classes starting with a lowercase letter in basic completion
+
 ide.completion.delay.autopopup.until.completed=false
 # suppress inspection "UnusedProperty"
 ide.completion.delay.autopopup.until.completed.description=Controls if completion autopopup is shown immediately and populated in background, or delayed until all suggestion are calculated