Add additional tests for form-decode corner cases

Author: camdez

test/ring/util/test/codec.clj

@@ -65,6 +65,14 @@
     "a=b%2Fc" {"a" "b/c"}
     "a=b&c"   {"a" "b" "c" ""}
     "a=&b=c"  {"a" "" "b" "c"}
-    "a&b=c"   {"a" "" "b" "c"})
+    "a&b=c"   {"a" "" "b" "c"}
+    "="       {"" ""}
+    "a="      {"a" ""}
+    "=b"      {"" "b"})
+  (testing "invalid URL encoding"
+    (are [x y] (= (form-decode x) y)
+      "%=b" {nil "b"}
+      "a=%" {"a" nil}
+      "%=%" {nil nil}))
   (is (= (form-decode "a=foo%FE%FF%00%2Fbar" "UTF-16")
          {"a" "foo/bar"})))