Fix string.format("%c", 0).

diff --git a/src/lib_string.c b/src/lib_string.c
index d1a60b617fb587172353b65f24ebaf0094c44651..c1e595c974f6531e053b4daecf2875c8cdb24467 100644 (file)
--- a/src/lib_string.c
+++ b/src/lib_string.c
@@ -850,20 +850,21 @@ LJLIB_CF(string_format)
     } else { /* format item */
       char form[MAX_FMTSPEC];  /* to store the format (`%...') */
       char buff[MAX_FMTITEM];  /* to store the formatted item */
+      int n = 0;
       if (++arg > top)
        luaL_argerror(L, arg, lj_obj_typename[0]);
       strfrmt = scanformat(L, strfrmt, form);
       switch (*strfrmt++) {
       case 'c':
-       sprintf(buff, form, lj_lib_checkint(L, arg));
+       n = sprintf(buff, form, lj_lib_checkint(L, arg));
        break;
       case 'd':  case 'i':
        addintlen(form);
-       sprintf(buff, form, num2intfrm(L, arg));
+       n = sprintf(buff, form, num2intfrm(L, arg));
        break;
       case 'o':  case 'u':  case 'x':  case 'X':
        addintlen(form);
-       sprintf(buff, form, num2uintfrm(L, arg));
+       n = sprintf(buff, form, num2uintfrm(L, arg));
        break;
       case 'e':  case 'E': case 'f': case 'g': case 'G': case 'a': case 'A': {
        TValue tv;
@@ -880,10 +881,10 @@ LJLIB_CF(string_format)
          nbuf[len] = '\0';
          for (p = form; *p < 'A' && *p != '.'; p++) ;
          *p++ = 's'; *p = '\0';
-         sprintf(buff, form, nbuf);
+         n = sprintf(buff, form, nbuf);
          break;
        }
-       sprintf(buff, form, (double)tv.n);
+       n = sprintf(buff, form, (double)tv.n);
        break;
        }
       case 'q':
@@ -902,14 +903,14 @@ LJLIB_CF(string_format)
          luaL_addvalue(&b);
          continue;
        }
-       sprintf(buff, form, strdata(str));
+       n = sprintf(buff, form, strdata(str));
        break;
        }
       default:
        lj_err_callerv(L, LJ_ERR_STRFMTO, *(strfrmt -1));
        break;
       }
-      luaL_addlstring(&b, buff, strlen(buff));
+      luaL_addlstring(&b, buff, n);
     }
   }
   luaL_pushresult(&b);