mruby-string-utf8: UTF-8 string may contail NUL; #1646

mrbgems/mruby-string-ext/test/string.rb

@@ -21,7 +21,6 @@ end
 
 assert('String#strip') do
   s = "  abc  "
-  s.strip
   "".strip == "" and " \t\r\n\f\v".strip == "" and
   "\0a\0".strip == "\0a" and
   "abc".strip     == "abc" and

mrbgems/mruby-string-utf8/src/string.c

@@ -26,7 +26,7 @@ utf8len(unsigned char* p)
   int    i;
 
   if (*p == 0)
-    return 0;
+    return 1;
   len = utf8len_tab[*p];
   for (i = 1; i < len; ++i)
     if ((p[i] & 0xc0) != 0x80)
@@ -39,7 +39,8 @@ mrb_utf8_strlen(mrb_value str)
 {
   size_t total = 0;
   unsigned char* p = (unsigned char*) RSTRING_PTR(str);
-  while (*p) {
+  unsigned char* e = p + RSTRING_LEN(str);
+  while (p<e) {
     p += utf8len(p);
     total++;
   }
@@ -110,11 +111,14 @@ str_subseq(mrb_state *mrb, mrb_value str, mrb_int beg, mrb_int len)
 {
   int i;
   unsigned char *p = (unsigned char*) RSTRING_PTR(str), *t;
-  for (i = 0; i < beg && *p; i++) {
+  unsigned char *e = p + RSTRING_LEN(str);
+  
+
+  for (i = 0; i < beg && p<e; i++) {
     p += utf8len(p);
   }
   t = p;
-  for (i = 0; i < len && *p; i++) {
+  for (i = 0; i < len && t<e; i++) {
     t += utf8len(t);
   }
   return mrb_str_new(mrb, (const char*)p, (int)(t - p));
@@ -129,7 +133,8 @@ str_substr(mrb_state *mrb, mrb_value str, mrb_int beg, mrb_int len)
   if (len < 0) return mrb_nil_value();
   if (len8 == 0) {
     len = 0;
-  } else if (beg < 0) {
+  }
+  else if (beg < 0) {
     beg = len8 + beg;
   }
   if (beg > len8) return mrb_nil_value();