fix behavior of printf with alt-form octal, zero precision, zero value

in this case there are two conflicting rules in play: that an explicit
precision of zero with the value zero produces no output, and that the
'#' modifier for octal increases the precision sufficiently to yield a
leading zero. ISO C (7.19.6.1 paragraph 6 in C99+TC3) includes a
parenthetical remark to clarify that the precision-increasing behavior
takes precedence, but the corresponding text in POSIX off of which I
based the implementation is missing this remark.

this issue was covered in WG14 DR#151.
This commit is contained in:
Rich Felker 2014-11-15 12:16:19 -05:00
parent ec4318943a
commit b91cdbe2bc
1 changed files with 1 additions and 1 deletions

View File

@ -570,7 +570,7 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,
if (0) {
case 'o':
a = fmt_o(arg.i, z);
if ((fl&ALT_FORM) && arg.i) prefix+=5, pl=1;
if ((fl&ALT_FORM) && p<z-a+1) p=z-a+1;
} if (0) {
case 'd': case 'i':
pl=1;