From ef01d133bc6d226fbbfe1fb7e78149731ef6b5e9 Mon Sep 17 00:00:00 2001
From: Dmitry Batrak <Dmitry.Batrak@jetbrains.com>
Date: Tue, 17 Jul 2018 14:49:39 +0300
Subject: [PATCH] IDEA-195668 Do not show completion hints in improper context

---
 .../codeInsight/completion/JavaMethodCallElement.java    | 9 ++++++++-
 .../java/codeInsight/completion/CompletionHintsTest.java | 8 +++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodCallElement.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodCallElement.java
index 44d603aefdf0..86ea31d2ee47 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodCallElement.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodCallElement.java
@@ -310,11 +310,18 @@ public class JavaMethodCallElement extends LookupItem<PsiMethod> implements Type
 
     CaretModel caretModel = editor.getCaretModel();
     int offset = caretModel.getOffset();
+
+    int afterParenOffset = offset + 1;
+    if (afterParenOffset < document.getTextLength() &&
+        Character.isJavaIdentifierPart(document.getImmutableCharSequence().charAt(afterParenOffset))) {
+      return;
+    }
+
     int braceOffset = offset - 1;
     int numberOfParametersToDisplay = parametersCount > 1 && PsiImplUtil.isVarArgs(method) ? parametersCount - 1 : parametersCount;
     int numberOfCommas = Math.min(numberOfParametersToDisplay, limit) - 1;
     String commas = Registry.is("editor.completion.hints.virtual.comma") ? "" : StringUtil.repeat(", ", numberOfCommas);
-    editor.getDocument().insertString(offset, commas);
+    document.insertString(offset, commas);
 
     PsiDocumentManager.getInstance(project).commitDocument(document);
     MethodParameterInfoHandler handler = new MethodParameterInfoHandler();
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/CompletionHintsTest.java b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/CompletionHintsTest.java
index d26a90eaa30c..57c16765562d 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/CompletionHintsTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/CompletionHintsTest.java
@@ -1369,7 +1369,7 @@ public class CompletionHintsTest extends AbstractParameterInfoTestCase {
                           "}");
   }
 
-  public void testCaretMovementOverVirtualComma() throws Exception {
+  public void testCaretMovementOverVirtualComma() {
     enableVirtualComma();
 
     configureJava("class C { void m() { System.getPro<caret> } }");
@@ -1380,6 +1380,12 @@ public class CompletionHintsTest extends AbstractParameterInfoTestCase {
     checkResultWithInlays("class C { void m() { System.getProperty(<Hint text=\"key:\"/>, <HINT text=\"def:\"/><caret>) } }");
   }
 
+  public void testHintsAreNotShownInImproperContext() {
+    configureJava("class C { void m() { int a = Math.ma<caret>5; } }");
+    complete("max(int a, int b)");
+    checkResult("class C { void m() { int a = Math.max(<caret>)5; } }");
+  }
+
   private void checkResultWithInlays(String text) {
     myFixture.checkResultWithInlays(text);
   }