Better check of the level in arguments

diff --git a/Upper.xs b/Upper.xs
index 231acccc4dbf105c942243cdb2502a5cf28f4ea9..60e8a0c80ecab6b44391c8d60bfe0703a7b58964 100644 (file)
--- a/Upper.xs
+++ b/Upper.xs
@@ -569,7 +569,7 @@ STATIC void su_unwind(pTHX_ void *ud_) {
  if (items > A) {        \
   SV *lsv = ST(A);       \
   if (SvOK(lsv))         \
-   level = SvUV(lsv);    \
+   level = SvIV(lsv);    \
   if (level < 0)         \
    XSRETURN(0);          \
  }                       \
@@ -578,10 +578,17 @@ STATIC void su_unwind(pTHX_ void *ud_) {
 
 #define SU_DOPOPTOCX(t)                    \
  STMT_START {                              \
-  I32 i, cxix = cxstack_ix, from = 0;      \
-  if (items)                               \
-   from = SvIV(ST(0));                     \
-  for (i = cxix - from; i >= 0; --i) {     \
+  I32 i, cxix = cxstack_ix, level = 0;     \
+  if (items) {                             \
+   SV *lsv = ST(0);                        \
+   if (SvOK(lsv))                          \
+    level = SvIV(lsv);                     \
+   if (level < 0)                          \
+    level = 0;                             \
+   else if (level > cxix)                  \
+    level = cxix;                          \
+  }                                        \
+  for (i = cxix - level; i >= 0; --i) {    \
    if (CxTYPE(&cxstack[i]) == t) {         \
     ST(0) = sv_2mortal(newSViv(cxix - i)); \
     XSRETURN(1);                           \
@@ -598,19 +605,20 @@ XS(XS_Scope__Upper_unwind) {
 #else
  dXSARGS;
 #endif
- I32 from = 0, cxix = cxstack_ix;
+ I32 level = 0, cxix = cxstack_ix;
  su_ud_unwind *ud;
- SV *level;
  PERL_UNUSED_VAR(cv); /* -W */
  PERL_UNUSED_VAR(ax); /* -Wall */
  if (items) {
-  from = SvIV(ST(items - 1));
-  if (from < 0)
-   from = 0;
-  else if (from > cxix)
-   from = cxix;
+  SV *lsv = ST(items - 1);
+  if (SvOK(lsv))
+   level = SvIV(lsv);
+  if (level < 0)
+   level = 0;
+  else if (level > cxix)
+   level = cxix;
  }
- cxix -= from;
+ cxix -= level;
  do {
   PERL_CONTEXT *cx = cxstack + cxix;
   switch (CxTYPE(cx)) {