IDEA-209947 Explain CCE warnings; merge explanations from different states

GitOrigin-RevId: b83e85b4712257fd536bca806790e2878bbf89a8

java/java-tests/testData/inspection/dataFlow/tracker/IfBothNotNull.java

@@ -0,0 +1,22 @@
+/*
+Value is always false (x == null)
+  One of the following happens:
+    'x' was assigned (new Object())
+      Expression cannot be null as it's newly created object (new Object())
+    'x' was assigned ("foo")
+      Expression cannot be null as it's literal ("foo")
+ */
+
+class Test {
+  void test(boolean b) {
+    Object x;
+    if (b) {
+      x = new Object();
+    } else {
+      x = "foo";
+    }
+    if (<selection>x == null</selection>) {
+      
+    }
+  }
+}

java/java-tests/testData/inspection/dataFlow/tracker/IfBothNotNullReassign.java

@@ -0,0 +1,24 @@
+/*
+Value is always false (y == null)
+  'y' was assigned (x)
+    One of the following happens:
+      'x' was assigned (new Object())
+        Expression cannot be null as it's newly created object (new Object())
+      'x' was assigned ("foo")
+        Expression cannot be null as it's literal ("foo")
+ */
+
+class Test {
+  void test(boolean b) {
+    Object x;
+    if (b) {
+      x = new Object();
+    } else {
+      x = "foo";
+    }
+    Object y = x;
+    if (<selection>y == null</selection>) {
+      
+    }
+  }
+}

java/java-tests/testData/inspection/dataFlow/tracker/WrongCastSimple.java

@@ -0,0 +1,13 @@
+/*
+Cast may fail ((Integer)x)
+  An object type is exactly String which is not a subtype of Integer (x)
+    Type of 'x' is known from line #9 (x instanceof String)
+ */
+
+class Test {
+  void test(Object x) {
+    if (x instanceof String) {
+      System.out.println(<selection>(Integer)x</selection>);
+    }
+  }
+}

java/java-tests/testData/inspection/dataFlow/tracker/WrongCastThreeStates.java

@@ -0,0 +1,18 @@
+/*
+Cast may fail ((Integer)x)
+  An execution might exist where...
+    An object type is exactly Double which is not a subtype of Integer (x)
+      Type of 'x' is known from line #14 (x instanceof Double)
+    An object type is exactly String which is not a subtype of Integer (x)
+      Type of 'x' is known from line #12 (x instanceof String)
+ */
+
+class Test {
+  void test(Object x) {
+    if (x instanceof String) {
+    }
+    if (x instanceof Double) {
+    }
+    System.out.println(<selection>(Integer)x</selection>);
+  }
+}

java/java-tests/testData/inspection/dataFlow/tracker/WrongCastTwoStates.java

@@ -0,0 +1,14 @@
+/*
+Cast may fail ((Integer)x)
+  An execution might exist where...
+    An object type is exactly String which is not a subtype of Integer (x)
+      Type of 'x' is known from line #10 (x instanceof String)
+ */
+
+class Test {
+  void test(Object x) {
+    if (x instanceof String) {
+    }
+    System.out.println(<selection>(Integer)x</selection>);
+  }
+}