IDEA-78370

java/java-impl/src/com/intellij/codeInspection/dataFlow/DfaMemoryStateImpl.java

@@ -257,6 +257,8 @@ public class DfaMemoryStateImpl implements DfaMemoryState {
   }
 
   public void setVarValue(DfaVariableValue var, DfaValue value) {
+    if (var == value) return;
+
     flushVariable(var);
     if (value instanceof DfaUnknownValue) return;
 

java/java-tests/testData/inspection/dataFlow/IDEADEV78370/expected.xml

@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<problems/>
+

java/java-tests/testData/inspection/dataFlow/IDEADEV78370/src/NoWarnings.java

@@ -0,0 +1,8 @@
+import org.jetbrains.annotations.Nullable;
+
+public class NoWarnings {
+    int f(@Nullable String value)  {
+        value = value == null ? "" : value;
+        return value.hashCode();
+    }
+}

java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspectionTest.java

@@ -81,6 +81,7 @@ public class DataFlowInspectionTest extends InspectionTestCase {
   public void testIDEADEV74518() throws Exception { doTest(); }
   public void testIDEADEV74518_2() throws Exception { doTest(); }
   public void testIDEADEV77819() throws Exception { doTest(); }
+  public void testIDEADEV78370() throws Exception { doTest(); }
 
   public void testRegressionByPti() throws Exception { doTest(); }