WIP - mpaland#109, mpaland#110

printf.c

@@ -231,6 +231,7 @@ static size_t _ntoa_format(out_fct_type out, char* buffer, size_t idx, size_t ma
 {
  // pad leading zeros
  if (!(flags & FLAGS_LEFT)) {
+ size_t initial_len = len;
  if (width && (flags & FLAGS_ZEROPAD) && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
  width--;
  }
@@ -240,6 +241,12 @@ static size_t _ntoa_format(out_fct_type out, char* buffer, size_t idx, size_t ma
  while ((flags & FLAGS_ZEROPAD) && (len < width) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
  buf[len++] = '0';
  }
+ if (base == 8U && (flags & FLAGS_HASH)) {
+ if (len > initial_len) {
+ // Since we've written some zeros, we've satisfied the alternative format leading space requirement
+ flags &= ~FLAGS_HASH;
+ }
+ }
  }
 
  // handle hash
@@ -286,13 +293,18 @@ static size_t _ntoa_long(out_fct_type out, char* buffer, size_t idx, size_t maxl
  char buf[PRINTF_NTOA_BUFFER_SIZE];
  size_t len = 0U;
 
- // no hash for 0 values
  if (!value) {
+ if (!(flags & FLAGS_PRECISION)
+ || (base == 8U && (flags & ~FLAGS_HASH))
+ ) {
+ buf[len++] = '0';
+ }
  flags &= ~FLAGS_HASH;
+ // We drop this flag this since either the alternative and regular modes of the specifier
+ // don't differ on 0 values, or (in the case of octal) we've already provided the special
+ // handling for this mode.
  }
-
- // write if precision != 0 and value is != 0
- if (!(flags & FLAGS_PRECISION) || value) {
+ else {
  do {
  const char digit = (char)(value % base);
  buf[len++] = (char)(digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10);