Old-style custom matchers (those which call this.report()) are not supported with the ".not" matcher negation syntax.

spec/suites/MatchersSpec.js

@@ -513,6 +513,22 @@ describe("jasmine.Matchers", function() {
       match(false).not.custom();
       expect(lastResult().message).toEqual("Passed.");
     });
+
+    it("should make old-style custom matchers blow up, but only when negated", function() {
+      spec.addMatchers({
+        custom: function() {
+          this.report();
+        }
+      });
+
+      expect(function() {
+        match(true).custom();
+      }).not.toThrow();
+
+      expect(function() {
+        match(true).not.custom();
+      }).toThrow();
+    });
   });
 
   describe("spy matchers >>", function() {