From 244c7f0164a29b410f684eab3a101fcb66e805f6 Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Sat, 8 Dec 2018 16:56:57 +0700
Subject: [PATCH] IDEA-203812 bad code green: switch expression does not have
 any case clauses

---
 .../codeInsight/daemon/impl/analysis/HighlightUtil.java     | 2 +-
 .../advHighlighting12/SwitchExpressions.java                | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightUtil.java b/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightUtil.java
index b3e248e47eab..5a44d6334a58 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightUtil.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightUtil.java
@@ -1996,7 +1996,7 @@ public class HighlightUtil extends HighlightUtilBase {
       Set<String> missingConstants = new HashSet<>();
       boolean exhaustive = hasDefaultCase;
       if (!exhaustive) {
-        if (selectorType instanceof PsiClassType) {
+        if (!values.isEmpty() && selectorType instanceof PsiClassType) {
           PsiClass type = ((PsiClassType)selectorType).resolve();
           if (type != null && type.isEnum()) {
             for (PsiField field : type.getFields()) {
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting12/SwitchExpressions.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting12/SwitchExpressions.java
index 2d914541d1a3..c68aaae269ce 100644
--- a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting12/SwitchExpressions.java
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting12/SwitchExpressions.java
@@ -58,4 +58,10 @@ class SwitchExpressions {
       });
     }
   }
+  
+  enum Empty {}
+  
+  boolean testEmpty(Empty e) {
+    return switch (<error descr="'switch' expression does not have any case clauses">e</error>) {};
+  }
 }
\ No newline at end of file