Java: Don't extract method where it's not safe because of nullable result (IDEA-167391)

java/java-tests/testData/refactoring/extractMethod/ExitPoints10.java

@@ -0,0 +1,16 @@
+class C {
+    private int[] list;
+
+    private Integer find(int id) {
+        <selection>
+        int n = 0;
+        for (int n1 : list) {
+            n = n1;
+            if (n == id) {
+                return n <= 0 ? null : n;
+            }
+        }
+        </selection>
+        throw new RuntimeException();
+    }
+}

java/java-tests/testData/refactoring/extractMethod/ExitPoints11.java

@@ -0,0 +1,12 @@
+class C {
+    private int[] list;
+
+    private int find(int id) {
+        <selection>for (int n : list) {
+            if (n == id) {
+                return n <= 0 ? 0 : n;
+            }
+        }</selection>
+        throw new RuntimeException();
+    }
+}

java/java-tests/testData/refactoring/extractMethod/ExitPoints11_after.java

@@ -0,0 +1,21 @@
+import org.jetbrains.annotations.Nullable;
+
+class C {
+    private int[] list;
+
+    private int find(int id) {
+        Integer n = newMethod(id);
+        if (n != null) return n;
+        throw new RuntimeException();
+    }
+
+    @Nullable
+    private Integer newMethod(int id) {
+        for (int n : list) {
+            if (n == id) {
+                return n <= 0 ? 0 : n;
+            }
+        }
+        return null;
+    }
+}

java/java-tests/testSrc/com/intellij/java/refactoring/ExtractMethodTest.java

@@ -95,6 +95,14 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     doTest();
   }
 
+  public void testExitPoints10() throws Exception {
+    doExitPointsTest(false);
+  }
+
+  public void testExitPoints11() throws Exception {
+    doTest();
+  }
+
   public void testNotNullCheckNameConflicts() throws Exception {
     doTest();
   }