Undocumented NPE if Stapler.getCurrent() called outside an HTTP han…

…dling thread (#596)

core/src/main/java/org/kohsuke/stapler/Stapler.java

@@ -1048,6 +1048,7 @@ public ClassLoader getClassLoader() {
 
     /**
      * Gets the current {@link StaplerRequest2} that the calling thread is associated with.
+     * @return null, if called from outside an HTTP handling thread
      */
     public static StaplerRequest2 getCurrentRequest2() {
         return CURRENT_REQUEST.get();
@@ -1064,6 +1065,7 @@ public static StaplerRequest getCurrentRequest() {
 
     /**
      * Gets the current {@link StaplerResponse2} that the calling thread is associated with.
+     * @return null, if called from outside an HTTP handling thread
      */
     public static StaplerResponse2 getCurrentResponse2() {
         return CURRENT_RESPONSE.get();
@@ -1080,9 +1082,11 @@ public static StaplerResponse getCurrentResponse() {
 
     /**
      * Gets the current {@link Stapler} that the calling thread is associated with.
+     * @return null, if called from outside an HTTP handling thread
      */
     public static Stapler getCurrent() {
-        return CURRENT_REQUEST.get().getStapler();
+        var req = CURRENT_REQUEST.get();
+        return req != null ? req.getStapler() : null;
     }
 
     /**

core/src/test/java/org/kohsuke/stapler/StaplerTest.java

@@ -91,4 +91,8 @@ public void testToFileOnUnix() throws Exception {
                     new URL("file:/tmp/" + path));
         }
     }
+
+    public void testGetCurrent() throws Exception {
+        assertNull("may be called outside an HTTP handling thread", Stapler.getCurrent());
+    }
 }