From b65a8a3a35cbe21f2635aaddacc00aa2944265dc Mon Sep 17 00:00:00 2001
From: Peter Gromov <peter@jetbrains.com>
Date: Wed, 2 Sep 2020 18:09:12 +0200
Subject: [PATCH] java: fix PIEAE when completing a constructor call
 invalidates the class being completed

GitOrigin-RevId: bf6a03e359482f777e63e38383ecc4160cca82ec
---
 .../completion/JavaClassNameInsertHandler.java         | 10 +++++++---
 ...onsWhenCompletingInapplicableClassNameAfterNew.java |  7 +++++++
 ...nCompletingInapplicableClassNameAfterNew_after.java |  7 +++++++
 .../codeInsight/completion/NormalCompletionTest.groovy |  2 ++
 4 files changed, 23 insertions(+), 3 deletions(-)
 create mode 100644 java/java-tests/testData/codeInsight/completion/normal/NoExceptionsWhenCompletingInapplicableClassNameAfterNew.java
 create mode 100644 java/java-tests/testData/codeInsight/completion/normal/NoExceptionsWhenCompletingInapplicableClassNameAfterNew_after.java

diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaClassNameInsertHandler.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaClassNameInsertHandler.java
index 41308f7e2fd3..aead8a0c1339 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaClassNameInsertHandler.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaClassNameInsertHandler.java
@@ -52,6 +52,7 @@ class JavaClassNameInsertHandler implements InsertHandler<JavaPsiClassReferenceE
     PsiJavaCodeReferenceElement ref = position != null && position.getParent() instanceof PsiJavaCodeReferenceElement ?
                                       (PsiJavaCodeReferenceElement) position.getParent() : null;
     PsiClass psiClass = item.getObject();
+    SmartPsiElementPointer<PsiClass> classPointer = SmartPointerManager.createPointer(psiClass);
     final Project project = context.getProject();
 
     final Editor editor = context.getEditor();
@@ -90,18 +91,21 @@ class JavaClassNameInsertHandler implements InsertHandler<JavaPsiClassReferenceE
     refEnd = context.trackOffset(context.getTailOffset(), false);
 
     context.commitDocument();
+
+    psiClass = classPointer.dereference();
+
     if (item.getUserData(JavaChainLookupElement.CHAIN_QUALIFIER) == null &&
         shouldInsertParentheses(file.findElementAt(context.getTailOffset() - 1))) {
       if (context.getCompletionChar() == Lookup.REPLACE_SELECT_CHAR) {
         overwriteTopmostReference(context);
         context.commitDocument();
       }
-      if (ConstructorInsertHandler.insertParentheses(context, item, psiClass, false)) {
+      if (psiClass != null && ConstructorInsertHandler.insertParentheses(context, item, psiClass, false)) {
         fillTypeArgs |= psiClass.hasTypeParameters() && PsiUtil.getLanguageLevel(file).isAtLeast(LanguageLevel.JDK_1_5);
       }
     }
     else if (insertingAnnotation(context, item)) {
-      if (shouldHaveAnnotationParameters(psiClass)) {
+      if (psiClass != null && shouldHaveAnnotationParameters(psiClass)) {
         JavaCompletionUtil.insertParentheses(context, item, false, true);
       }
       if (context.getCompletionChar() == Lookup.NORMAL_SELECT_CHAR || context.getCompletionChar() == Lookup.COMPLETE_STATEMENT_SELECT_CHAR) {
@@ -117,7 +121,7 @@ class JavaClassNameInsertHandler implements InsertHandler<JavaPsiClassReferenceE
       JavaCompletionUtil.promptTypeArgs(context, context.getOffset(refEnd));
     }
     else if (context.getCompletionChar() == Lookup.COMPLETE_STATEMENT_SELECT_CHAR &&
-             psiClass.getTypeParameters().length == 1 &&
+             psiClass != null && psiClass.getTypeParameters().length == 1 &&
              PsiUtil.getLanguageLevel(file).isAtLeast(LanguageLevel.JDK_1_5)) {
       wrapFollowingTypeInGenerics(context, context.getOffset(refEnd));
     }
diff --git a/java/java-tests/testData/codeInsight/completion/normal/NoExceptionsWhenCompletingInapplicableClassNameAfterNew.java b/java/java-tests/testData/codeInsight/completion/normal/NoExceptionsWhenCompletingInapplicableClassNameAfterNew.java
new file mode 100644
index 000000000000..da7b38806fd1
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/normal/NoExceptionsWhenCompletingInapplicableClassNameAfterNew.java
@@ -0,0 +1,7 @@
+class Cx {
+    Another F = new C<caret>Another(
+            f -> ((String)f).stream().anyMatch(c -> c.m(f) != null));
+
+}
+
+class Another {}
diff --git a/java/java-tests/testData/codeInsight/completion/normal/NoExceptionsWhenCompletingInapplicableClassNameAfterNew_after.java b/java/java-tests/testData/codeInsight/completion/normal/NoExceptionsWhenCompletingInapplicableClassNameAfterNew_after.java
new file mode 100644
index 000000000000..0ed168b6e9fd
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/normal/NoExceptionsWhenCompletingInapplicableClassNameAfterNew_after.java
@@ -0,0 +1,7 @@
+class Cx {
+    Another F = new Cx()<caret>Another(
+            f -> ((String)f).stream().anyMatch(c -> c.m(f) != null));
+
+}
+
+class Another {}
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionTest.groovy b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionTest.groovy
index 937aebd9c166..475b3057c151 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionTest.groovy
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionTest.groovy
@@ -2216,4 +2216,6 @@ class Abc {
       assert !lookup
     }.assertTiming()
   }
+
+  void testNoExceptionsWhenCompletingInapplicableClassNameAfterNew() { doTest('\n') }
 }