java parameter info: revert unsafe fix for IDEA-184821, add a test (IDEA-CR-28480)

java/java-impl/src/com/intellij/codeInsight/hint/api/impls/MethodParameterInfoHandler.java

@@ -247,13 +247,15 @@ public class MethodParameterInfoHandler implements ParameterInfoHandlerWithTabAc
     for (int i = 0; i < candidates.length; i++) {
       CandidateInfo candidate = (CandidateInfo)candidates[i];
       PsiMethod method = (PsiMethod)candidate.getElement();
-      if (!method.isValid() || !candidate.getSubstitutor().isValid()) {
-        // this may sometimes happen e,g, when editing method call in field initializer candidates in the same file get invalidated
+      if (!method.isValid()) continue;
+      PsiSubstitutor substitutor = getCandidateInfoSubstitutor(o, candidate, method == realResolve);
+      assert substitutor != null;
+
+      if (!method.isValid() || !substitutor.isValid()) {
+          // this may sometimes happen e,g, when editing method call in field initializer candidates in the same file get invalidated
         context.setUIComponentEnabled(i, false);
         continue;
       }
-      PsiSubstitutor substitutor = getCandidateInfoSubstitutor(o, candidate, method == realResolve);
-      assert substitutor != null;
 
       PsiParameter[] parms = method.getParameterList().getParameters();
       boolean enabled = true;
@@ -726,7 +728,7 @@ public class MethodParameterInfoHandler implements ParameterInfoHandlerWithTabAc
     if (p instanceof CandidateInfo) {
       CandidateInfo info = (CandidateInfo)p;
       PsiMethod method = (PsiMethod)info.getElement();
-      if (!method.isValid() || !info.getSubstitutor().isValid()) {
+      if (!method.isValid()) {
         context.setUIComponentEnabled(false);
         return;
       }

java/java-tests/testData/codeInsight/parameterInfo/TypeInvalidationByCompletion.java

@@ -0,0 +1,7 @@
+import java.util.ArrayList;
+
+class A{
+    void foo(){
+        new ArrayList<String>().stream().collect(toSe<caret>)
+    }
+}

java/java-tests/testData/codeInsight/parameterInfo/TypeInvalidationByCompletion_after.java

@@ -0,0 +1,8 @@
+import java.util.ArrayList;
+import java.util.stream.Collectors;
+
+class A{
+    void foo(){
+        new ArrayList<String>().stream().collect(Collectors.toSet())<caret>
+    }
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/ParameterInfoTest.java

@@ -9,6 +9,7 @@ import com.intellij.codeInsight.hint.api.impls.MethodParameterInfoHandler;
 import com.intellij.codeInsight.lookup.LookupElement;
 import com.intellij.codeInsight.lookup.LookupElementPresentation;
 import com.intellij.ide.highlighter.JavaFileType;
+import com.intellij.idea.Bombed;
 import com.intellij.lang.parameterInfo.CreateParameterInfoContext;
 import com.intellij.lang.parameterInfo.ParameterInfoUIContextEx;
 import com.intellij.openapi.actionSystem.IdeActions;
@@ -26,6 +27,8 @@ import com.intellij.testFramework.utils.parameterInfo.MockUpdateParameterInfoCon
 import com.intellij.util.ui.UIUtil;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Calendar;
+
 public class ParameterInfoTest extends LightCodeInsightFixtureTestCase {
   @Override
   protected String getBasePath() {
@@ -339,4 +342,27 @@ public class ParameterInfoTest extends LightCodeInsightFixtureTestCase {
     assertEquals(itemsToShow[lineIndex], updateParameterInfo(handler, list, itemsToShow).getHighlightedParameter());
   }
 
+  @Bombed(month = Calendar.JANUARY, day = 22, user = "anna")
+  public void testTypeInvalidationByCompletion() {
+    myFixture.configureByFile(getTestName(false) + ".java");
+
+    MethodParameterInfoHandler handler = new MethodParameterInfoHandler();
+    CreateParameterInfoContext context = new MockCreateParameterInfoContext(getEditor(), getFile());
+    PsiExpressionList argList = handler.findElementForParameterInfo(context);
+    assertNotNull(argList);
+    Object[] items = context.getItemsToShow();
+    assertSize(2, items);
+    updateParameterInfo(handler, argList, items);
+    
+    myFixture.completeBasic();
+    myFixture.type('\n');
+
+    assertTrue(argList.isValid());
+    // items now contain references to invalid PSI
+    updateParameterInfo(handler, argList, items);
+    assertSize(2, context.getItemsToShow());
+    
+    myFixture.checkResultByFile(getTestName(false) + "_after.java");
+  }
+
 }