TonBERRY/micropython
3
0
Fork 0
Code Pull Requests Activity

py/mpprint: Fix length calculation for strings with precision-modifier.

Browse Source 
Two issues are tackled:

1. The calculation of the correct length to print is fixed to treat the
   precision as a maximum length instead as the exact length.
   This is done for both qstr (%q) and for regular str (%s).

2. Fix the incorrect use of mp_printf("%.*s") to mp_print_strn().

   Because of the fix of above issue, some testcases that would print
   an embedded null-byte (^@ in test-output) would now fail.
   The bug here is that "%s" was used to print null-bytes. Instead,
   mp_print_strn is used to make sure all bytes are outputted and the
   exact length is respected.

Test-cases are added for both %s and %q with a combination of precision
and padding specifiers.
This commit is contained in:
Joris Peeraer
2020-10-22 10:38:03 +02:00
committed by Damien George
parent dde0735ac1
commit 5020b14d54
5 changed files with 12 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
py/mpprint.c
View File

@@ -484,10 +484,10 @@ int mp_vprintf(const mp_print_t *print, const char *fmt, va_list args) {
qstr qst = va_arg(args, qstr);
size_t len;
const char *str = (const char *)qstr_data(qst, &len);
if (prec < 0) {
prec = len;
if (prec >= 0 && (size_t)prec < len) {
len = prec;
}
chrs += mp_print_strn(print, str, prec, flags, fill, width);
chrs += mp_print_strn(print, str, len, flags, fill, width);
break;
}
case 's': {
@@ -499,10 +499,11 @@ int mp_vprintf(const mp_print_t *print, const char *fmt, va_list args) {
break;
}
#endif
if (prec < 0) {
prec = strlen(str);
size_t len = strlen(str);
if (prec >= 0 && (size_t)prec < len) {
len = prec;
}
chrs += mp_print_strn(print, str, prec, flags, fill, width);
chrs += mp_print_strn(print, str, len, flags, fill, width);
break;
}
case 'd': {