Fix asm roundtrip issue.

src/core/asm.c

@@ -560,6 +560,9 @@ static JanetAssembleResult janet_asm1(JanetAssembler *parent, Janet source, int
     x = janet_get1(s, janet_ckeywordv("vararg"));
     if (janet_truthy(x)) def->flags |= JANET_FUNCDEF_FLAG_VARARG;
 
+    /* Initialize slotcount */
+    def->slotcount = !!(def->flags & JANET_FUNCDEF_FLAG_VARARG) + def->arity;
+
     /* Check structarg */
     x = janet_get1(s, janet_ckeywordv("structarg"));
     if (janet_truthy(x)) def->flags |= JANET_FUNCDEF_FLAG_STRUCTARG;
@@ -784,8 +787,9 @@ static JanetAssembleResult janet_asm1(JanetAssembler *parent, Janet source, int
     }
 
     /* Verify the func def */
-    if (janet_verify(def)) {
-        janet_asm_error(&a, "invalid assembly");
+    int verify_status = janet_verify(def);
+    if (verify_status) {
+        janet_asm_errorv(&a, janet_formatc("invalid assembly (%d)", verify_status));
     }
 
     /* Add final flags */

test/suite-asm.janet

@@ -51,5 +51,13 @@
 (def f (asm (disasm (fn [x] (fn [y] (+ x y))))))
 (assert (= ((f 10) 37) 47) "asm environment tables")
 
+# issue #1424
+(assert-no-error "arity > used slots (issue #1424)"
+                 (asm
+                   (disasm
+                     (fn []
+                       (def foo (fn [one two] one))
+                       (foo 100 200)))))
+
 (end-suite)
 

test/suite-boot.janet

@@ -955,6 +955,10 @@
 (defn case-4 [&]
   (def x (break (break (break)))))
 (bytecode-roundtrip case-4)
+(defn case-5 []
+  (def foo (fn [one two] one))
+  (foo 100 200))
+(bytecode-roundtrip case-5)
 
 # Debug bytecode of these functions
 # (pp (disasm case-1))