patch 7.4.1168
Problem:    This doesn't give the right result: eval(string(v:true)). (Nikolay
            Pavlov)
Solution:   Make the string "v:true" instead of "true".
diff --git a/src/eval.c b/src/eval.c
index b4cb385..860bc35 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -7825,10 +7825,10 @@
 {
     switch (nr)
     {
-	case VVAL_FALSE: return "false";
-	case VVAL_TRUE: return "true";
-	case VVAL_NONE: return "none";
-	case VVAL_NULL: return "null";
+	case VVAL_FALSE: return "v:false";
+	case VVAL_TRUE: return "v:true";
+	case VVAL_NONE: return "v:none";
+	case VVAL_NULL: return "v:null";
     }
     EMSG2(_(e_intern2), "get_var_special_name()");
     return "42";