IDEA-143014 Wrong 'can be null' warning when assignment is done inside if condition

java/java-tests/testData/inspection/dataFlow/fixture/ConstantConditionsWithAssignmentsInside.java

@@ -8,8 +8,8 @@ class Contracts {
     if (y) System.out.println();
 
     int k = 1;
-    boolean z = (k +=1) == k; // returns true
-    if (z) System.out.println();
+    boolean z = <warning descr="Condition '(k +=1) == k' is always 'true'">(k +=1) == k</warning>; // returns true
+    if (<warning descr="Condition 'z' is always 'true'">z</warning>) System.out.println();
   }
 
 

java/java-tests/testData/inspection/dataFlow/fixture/IfConditionsWithAssignmentInside.java

@@ -0,0 +1,14 @@
+import org.jetbrains.annotations.Nullable;
+
+class Test {
+
+  @Nullable
+  private static native String getNext();
+
+  public static void test() {
+    String v = null;
+    while ((v = getNext()) != null) {
+      v.substring(1);
+    }
+  }
+}