* [musl] swprintf cannot handle the character 0xff
@ 2023-06-12 12:30 Bruno Haible
2023-06-12 20:22 ` Rich Felker
0 siblings, 1 reply; 7+ messages in thread
From: Bruno Haible @ 2023-06-12 12:30 UTC (permalink / raw)
To: musl
When swprintf is meant to convert a character to a wide character, through
the %c directive, it fails if that character is '\xff'.
Seen with musl libc 1.2.4, in Alpine Linux 3.18.0.
How to reproduce:
============================ foo.c ============================
#include <stdio.h>
#include <wchar.h>
int main ()
{
wchar_t buf[12];
for (int c = 1; c < 256; c++)
{
fprintf (stderr, "c = %d: ", c);
int ret = swprintf (buf, 12, L"%c", c);
if (ret >= 0)
fprintf (stderr, "OK, %d bytes\n", ret);
else
perror ("swprintf failed");
}
}
===============================================================
$ gcc -Wall foo.c
$ ./a.out
Expected output:
c = 1: OK, 1 bytes
c = 2: OK, 1 bytes
c = 3: OK, 1 bytes
c = 4: OK, 1 bytes
c = 5: OK, 1 bytes
c = 6: OK, 1 bytes
c = 7: OK, 1 bytes
c = 8: OK, 1 bytes
c = 9: OK, 1 bytes
c = 10: OK, 1 bytes
c = 11: OK, 1 bytes
c = 12: OK, 1 bytes
c = 13: OK, 1 bytes
c = 14: OK, 1 bytes
c = 15: OK, 1 bytes
c = 16: OK, 1 bytes
c = 17: OK, 1 bytes
c = 18: OK, 1 bytes
c = 19: OK, 1 bytes
c = 20: OK, 1 bytes
c = 21: OK, 1 bytes
c = 22: OK, 1 bytes
c = 23: OK, 1 bytes
c = 24: OK, 1 bytes
c = 25: OK, 1 bytes
c = 26: OK, 1 bytes
c = 27: OK, 1 bytes
c = 28: OK, 1 bytes
c = 29: OK, 1 bytes
c = 30: OK, 1 bytes
c = 31: OK, 1 bytes
c = 32: OK, 1 bytes
c = 33: OK, 1 bytes
c = 34: OK, 1 bytes
c = 35: OK, 1 bytes
c = 36: OK, 1 bytes
c = 37: OK, 1 bytes
c = 38: OK, 1 bytes
c = 39: OK, 1 bytes
c = 40: OK, 1 bytes
c = 41: OK, 1 bytes
c = 42: OK, 1 bytes
c = 43: OK, 1 bytes
c = 44: OK, 1 bytes
c = 45: OK, 1 bytes
c = 46: OK, 1 bytes
c = 47: OK, 1 bytes
c = 48: OK, 1 bytes
c = 49: OK, 1 bytes
c = 50: OK, 1 bytes
c = 51: OK, 1 bytes
c = 52: OK, 1 bytes
c = 53: OK, 1 bytes
c = 54: OK, 1 bytes
c = 55: OK, 1 bytes
c = 56: OK, 1 bytes
c = 57: OK, 1 bytes
c = 58: OK, 1 bytes
c = 59: OK, 1 bytes
c = 60: OK, 1 bytes
c = 61: OK, 1 bytes
c = 62: OK, 1 bytes
c = 63: OK, 1 bytes
c = 64: OK, 1 bytes
c = 65: OK, 1 bytes
c = 66: OK, 1 bytes
c = 67: OK, 1 bytes
c = 68: OK, 1 bytes
c = 69: OK, 1 bytes
c = 70: OK, 1 bytes
c = 71: OK, 1 bytes
c = 72: OK, 1 bytes
c = 73: OK, 1 bytes
c = 74: OK, 1 bytes
c = 75: OK, 1 bytes
c = 76: OK, 1 bytes
c = 77: OK, 1 bytes
c = 78: OK, 1 bytes
c = 79: OK, 1 bytes
c = 80: OK, 1 bytes
c = 81: OK, 1 bytes
c = 82: OK, 1 bytes
c = 83: OK, 1 bytes
c = 84: OK, 1 bytes
c = 85: OK, 1 bytes
c = 86: OK, 1 bytes
c = 87: OK, 1 bytes
c = 88: OK, 1 bytes
c = 89: OK, 1 bytes
c = 90: OK, 1 bytes
c = 91: OK, 1 bytes
c = 92: OK, 1 bytes
c = 93: OK, 1 bytes
c = 94: OK, 1 bytes
c = 95: OK, 1 bytes
c = 96: OK, 1 bytes
c = 97: OK, 1 bytes
c = 98: OK, 1 bytes
c = 99: OK, 1 bytes
c = 100: OK, 1 bytes
c = 101: OK, 1 bytes
c = 102: OK, 1 bytes
c = 103: OK, 1 bytes
c = 104: OK, 1 bytes
c = 105: OK, 1 bytes
c = 106: OK, 1 bytes
c = 107: OK, 1 bytes
c = 108: OK, 1 bytes
c = 109: OK, 1 bytes
c = 110: OK, 1 bytes
c = 111: OK, 1 bytes
c = 112: OK, 1 bytes
c = 113: OK, 1 bytes
c = 114: OK, 1 bytes
c = 115: OK, 1 bytes
c = 116: OK, 1 bytes
c = 117: OK, 1 bytes
c = 118: OK, 1 bytes
c = 119: OK, 1 bytes
c = 120: OK, 1 bytes
c = 121: OK, 1 bytes
c = 122: OK, 1 bytes
c = 123: OK, 1 bytes
c = 124: OK, 1 bytes
c = 125: OK, 1 bytes
c = 126: OK, 1 bytes
c = 127: OK, 1 bytes
c = 128: OK, 1 bytes
c = 129: OK, 1 bytes
c = 130: OK, 1 bytes
c = 131: OK, 1 bytes
c = 132: OK, 1 bytes
c = 133: OK, 1 bytes
c = 134: OK, 1 bytes
c = 135: OK, 1 bytes
c = 136: OK, 1 bytes
c = 137: OK, 1 bytes
c = 138: OK, 1 bytes
c = 139: OK, 1 bytes
c = 140: OK, 1 bytes
c = 141: OK, 1 bytes
c = 142: OK, 1 bytes
c = 143: OK, 1 bytes
c = 144: OK, 1 bytes
c = 145: OK, 1 bytes
c = 146: OK, 1 bytes
c = 147: OK, 1 bytes
c = 148: OK, 1 bytes
c = 149: OK, 1 bytes
c = 150: OK, 1 bytes
c = 151: OK, 1 bytes
c = 152: OK, 1 bytes
c = 153: OK, 1 bytes
c = 154: OK, 1 bytes
c = 155: OK, 1 bytes
c = 156: OK, 1 bytes
c = 157: OK, 1 bytes
c = 158: OK, 1 bytes
c = 159: OK, 1 bytes
c = 160: OK, 1 bytes
c = 161: OK, 1 bytes
c = 162: OK, 1 bytes
c = 163: OK, 1 bytes
c = 164: OK, 1 bytes
c = 165: OK, 1 bytes
c = 166: OK, 1 bytes
c = 167: OK, 1 bytes
c = 168: OK, 1 bytes
c = 169: OK, 1 bytes
c = 170: OK, 1 bytes
c = 171: OK, 1 bytes
c = 172: OK, 1 bytes
c = 173: OK, 1 bytes
c = 174: OK, 1 bytes
c = 175: OK, 1 bytes
c = 176: OK, 1 bytes
c = 177: OK, 1 bytes
c = 178: OK, 1 bytes
c = 179: OK, 1 bytes
c = 180: OK, 1 bytes
c = 181: OK, 1 bytes
c = 182: OK, 1 bytes
c = 183: OK, 1 bytes
c = 184: OK, 1 bytes
c = 185: OK, 1 bytes
c = 186: OK, 1 bytes
c = 187: OK, 1 bytes
c = 188: OK, 1 bytes
c = 189: OK, 1 bytes
c = 190: OK, 1 bytes
c = 191: OK, 1 bytes
c = 192: OK, 1 bytes
c = 193: OK, 1 bytes
c = 194: OK, 1 bytes
c = 195: OK, 1 bytes
c = 196: OK, 1 bytes
c = 197: OK, 1 bytes
c = 198: OK, 1 bytes
c = 199: OK, 1 bytes
c = 200: OK, 1 bytes
c = 201: OK, 1 bytes
c = 202: OK, 1 bytes
c = 203: OK, 1 bytes
c = 204: OK, 1 bytes
c = 205: OK, 1 bytes
c = 206: OK, 1 bytes
c = 207: OK, 1 bytes
c = 208: OK, 1 bytes
c = 209: OK, 1 bytes
c = 210: OK, 1 bytes
c = 211: OK, 1 bytes
c = 212: OK, 1 bytes
c = 213: OK, 1 bytes
c = 214: OK, 1 bytes
c = 215: OK, 1 bytes
c = 216: OK, 1 bytes
c = 217: OK, 1 bytes
c = 218: OK, 1 bytes
c = 219: OK, 1 bytes
c = 220: OK, 1 bytes
c = 221: OK, 1 bytes
c = 222: OK, 1 bytes
c = 223: OK, 1 bytes
c = 224: OK, 1 bytes
c = 225: OK, 1 bytes
c = 226: OK, 1 bytes
c = 227: OK, 1 bytes
c = 228: OK, 1 bytes
c = 229: OK, 1 bytes
c = 230: OK, 1 bytes
c = 231: OK, 1 bytes
c = 232: OK, 1 bytes
c = 233: OK, 1 bytes
c = 234: OK, 1 bytes
c = 235: OK, 1 bytes
c = 236: OK, 1 bytes
c = 237: OK, 1 bytes
c = 238: OK, 1 bytes
c = 239: OK, 1 bytes
c = 240: OK, 1 bytes
c = 241: OK, 1 bytes
c = 242: OK, 1 bytes
c = 243: OK, 1 bytes
c = 244: OK, 1 bytes
c = 245: OK, 1 bytes
c = 246: OK, 1 bytes
c = 247: OK, 1 bytes
c = 248: OK, 1 bytes
c = 249: OK, 1 bytes
c = 250: OK, 1 bytes
c = 251: OK, 1 bytes
c = 252: OK, 1 bytes
c = 253: OK, 1 bytes
c = 254: OK, 1 bytes
c = 255: OK, 1 bytes
Actual output:
c = 1: OK, 1 bytes
c = 2: OK, 1 bytes
c = 3: OK, 1 bytes
c = 4: OK, 1 bytes
c = 5: OK, 1 bytes
c = 6: OK, 1 bytes
c = 7: OK, 1 bytes
c = 8: OK, 1 bytes
c = 9: OK, 1 bytes
c = 10: OK, 1 bytes
c = 11: OK, 1 bytes
c = 12: OK, 1 bytes
c = 13: OK, 1 bytes
c = 14: OK, 1 bytes
c = 15: OK, 1 bytes
c = 16: OK, 1 bytes
c = 17: OK, 1 bytes
c = 18: OK, 1 bytes
c = 19: OK, 1 bytes
c = 20: OK, 1 bytes
c = 21: OK, 1 bytes
c = 22: OK, 1 bytes
c = 23: OK, 1 bytes
c = 24: OK, 1 bytes
c = 25: OK, 1 bytes
c = 26: OK, 1 bytes
c = 27: OK, 1 bytes
c = 28: OK, 1 bytes
c = 29: OK, 1 bytes
c = 30: OK, 1 bytes
c = 31: OK, 1 bytes
c = 32: OK, 1 bytes
c = 33: OK, 1 bytes
c = 34: OK, 1 bytes
c = 35: OK, 1 bytes
c = 36: OK, 1 bytes
c = 37: OK, 1 bytes
c = 38: OK, 1 bytes
c = 39: OK, 1 bytes
c = 40: OK, 1 bytes
c = 41: OK, 1 bytes
c = 42: OK, 1 bytes
c = 43: OK, 1 bytes
c = 44: OK, 1 bytes
c = 45: OK, 1 bytes
c = 46: OK, 1 bytes
c = 47: OK, 1 bytes
c = 48: OK, 1 bytes
c = 49: OK, 1 bytes
c = 50: OK, 1 bytes
c = 51: OK, 1 bytes
c = 52: OK, 1 bytes
c = 53: OK, 1 bytes
c = 54: OK, 1 bytes
c = 55: OK, 1 bytes
c = 56: OK, 1 bytes
c = 57: OK, 1 bytes
c = 58: OK, 1 bytes
c = 59: OK, 1 bytes
c = 60: OK, 1 bytes
c = 61: OK, 1 bytes
c = 62: OK, 1 bytes
c = 63: OK, 1 bytes
c = 64: OK, 1 bytes
c = 65: OK, 1 bytes
c = 66: OK, 1 bytes
c = 67: OK, 1 bytes
c = 68: OK, 1 bytes
c = 69: OK, 1 bytes
c = 70: OK, 1 bytes
c = 71: OK, 1 bytes
c = 72: OK, 1 bytes
c = 73: OK, 1 bytes
c = 74: OK, 1 bytes
c = 75: OK, 1 bytes
c = 76: OK, 1 bytes
c = 77: OK, 1 bytes
c = 78: OK, 1 bytes
c = 79: OK, 1 bytes
c = 80: OK, 1 bytes
c = 81: OK, 1 bytes
c = 82: OK, 1 bytes
c = 83: OK, 1 bytes
c = 84: OK, 1 bytes
c = 85: OK, 1 bytes
c = 86: OK, 1 bytes
c = 87: OK, 1 bytes
c = 88: OK, 1 bytes
c = 89: OK, 1 bytes
c = 90: OK, 1 bytes
c = 91: OK, 1 bytes
c = 92: OK, 1 bytes
c = 93: OK, 1 bytes
c = 94: OK, 1 bytes
c = 95: OK, 1 bytes
c = 96: OK, 1 bytes
c = 97: OK, 1 bytes
c = 98: OK, 1 bytes
c = 99: OK, 1 bytes
c = 100: OK, 1 bytes
c = 101: OK, 1 bytes
c = 102: OK, 1 bytes
c = 103: OK, 1 bytes
c = 104: OK, 1 bytes
c = 105: OK, 1 bytes
c = 106: OK, 1 bytes
c = 107: OK, 1 bytes
c = 108: OK, 1 bytes
c = 109: OK, 1 bytes
c = 110: OK, 1 bytes
c = 111: OK, 1 bytes
c = 112: OK, 1 bytes
c = 113: OK, 1 bytes
c = 114: OK, 1 bytes
c = 115: OK, 1 bytes
c = 116: OK, 1 bytes
c = 117: OK, 1 bytes
c = 118: OK, 1 bytes
c = 119: OK, 1 bytes
c = 120: OK, 1 bytes
c = 121: OK, 1 bytes
c = 122: OK, 1 bytes
c = 123: OK, 1 bytes
c = 124: OK, 1 bytes
c = 125: OK, 1 bytes
c = 126: OK, 1 bytes
c = 127: OK, 1 bytes
c = 128: OK, 1 bytes
c = 129: OK, 1 bytes
c = 130: OK, 1 bytes
c = 131: OK, 1 bytes
c = 132: OK, 1 bytes
c = 133: OK, 1 bytes
c = 134: OK, 1 bytes
c = 135: OK, 1 bytes
c = 136: OK, 1 bytes
c = 137: OK, 1 bytes
c = 138: OK, 1 bytes
c = 139: OK, 1 bytes
c = 140: OK, 1 bytes
c = 141: OK, 1 bytes
c = 142: OK, 1 bytes
c = 143: OK, 1 bytes
c = 144: OK, 1 bytes
c = 145: OK, 1 bytes
c = 146: OK, 1 bytes
c = 147: OK, 1 bytes
c = 148: OK, 1 bytes
c = 149: OK, 1 bytes
c = 150: OK, 1 bytes
c = 151: OK, 1 bytes
c = 152: OK, 1 bytes
c = 153: OK, 1 bytes
c = 154: OK, 1 bytes
c = 155: OK, 1 bytes
c = 156: OK, 1 bytes
c = 157: OK, 1 bytes
c = 158: OK, 1 bytes
c = 159: OK, 1 bytes
c = 160: OK, 1 bytes
c = 161: OK, 1 bytes
c = 162: OK, 1 bytes
c = 163: OK, 1 bytes
c = 164: OK, 1 bytes
c = 165: OK, 1 bytes
c = 166: OK, 1 bytes
c = 167: OK, 1 bytes
c = 168: OK, 1 bytes
c = 169: OK, 1 bytes
c = 170: OK, 1 bytes
c = 171: OK, 1 bytes
c = 172: OK, 1 bytes
c = 173: OK, 1 bytes
c = 174: OK, 1 bytes
c = 175: OK, 1 bytes
c = 176: OK, 1 bytes
c = 177: OK, 1 bytes
c = 178: OK, 1 bytes
c = 179: OK, 1 bytes
c = 180: OK, 1 bytes
c = 181: OK, 1 bytes
c = 182: OK, 1 bytes
c = 183: OK, 1 bytes
c = 184: OK, 1 bytes
c = 185: OK, 1 bytes
c = 186: OK, 1 bytes
c = 187: OK, 1 bytes
c = 188: OK, 1 bytes
c = 189: OK, 1 bytes
c = 190: OK, 1 bytes
c = 191: OK, 1 bytes
c = 192: OK, 1 bytes
c = 193: OK, 1 bytes
c = 194: OK, 1 bytes
c = 195: OK, 1 bytes
c = 196: OK, 1 bytes
c = 197: OK, 1 bytes
c = 198: OK, 1 bytes
c = 199: OK, 1 bytes
c = 200: OK, 1 bytes
c = 201: OK, 1 bytes
c = 202: OK, 1 bytes
c = 203: OK, 1 bytes
c = 204: OK, 1 bytes
c = 205: OK, 1 bytes
c = 206: OK, 1 bytes
c = 207: OK, 1 bytes
c = 208: OK, 1 bytes
c = 209: OK, 1 bytes
c = 210: OK, 1 bytes
c = 211: OK, 1 bytes
c = 212: OK, 1 bytes
c = 213: OK, 1 bytes
c = 214: OK, 1 bytes
c = 215: OK, 1 bytes
c = 216: OK, 1 bytes
c = 217: OK, 1 bytes
c = 218: OK, 1 bytes
c = 219: OK, 1 bytes
c = 220: OK, 1 bytes
c = 221: OK, 1 bytes
c = 222: OK, 1 bytes
c = 223: OK, 1 bytes
c = 224: OK, 1 bytes
c = 225: OK, 1 bytes
c = 226: OK, 1 bytes
c = 227: OK, 1 bytes
c = 228: OK, 1 bytes
c = 229: OK, 1 bytes
c = 230: OK, 1 bytes
c = 231: OK, 1 bytes
c = 232: OK, 1 bytes
c = 233: OK, 1 bytes
c = 234: OK, 1 bytes
c = 235: OK, 1 bytes
c = 236: OK, 1 bytes
c = 237: OK, 1 bytes
c = 238: OK, 1 bytes
c = 239: OK, 1 bytes
c = 240: OK, 1 bytes
c = 241: OK, 1 bytes
c = 242: OK, 1 bytes
c = 243: OK, 1 bytes
c = 244: OK, 1 bytes
c = 245: OK, 1 bytes
c = 246: OK, 1 bytes
c = 247: OK, 1 bytes
c = 248: OK, 1 bytes
c = 249: OK, 1 bytes
c = 250: OK, 1 bytes
c = 251: OK, 1 bytes
c = 252: OK, 1 bytes
c = 253: OK, 1 bytes
c = 254: OK, 1 bytes
c = 255: swprintf failed: Illegal byte sequence
This is a bug, because POSIX says that in the C / POSIX locale, "all byte
values are valid characters" [1].
Bruno
[1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbrtowc.html
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [musl] swprintf cannot handle the character 0xff
2023-06-12 12:30 [musl] swprintf cannot handle the character 0xff Bruno Haible
@ 2023-06-12 20:22 ` Rich Felker
2023-06-12 21:01 ` Rich Felker
0 siblings, 1 reply; 7+ messages in thread
From: Rich Felker @ 2023-06-12 20:22 UTC (permalink / raw)
To: Bruno Haible; +Cc: musl
[-- Attachment #1: Type: text/plain, Size: 12606 bytes --]
On Mon, Jun 12, 2023 at 02:30:44PM +0200, Bruno Haible wrote:
> When swprintf is meant to convert a character to a wide character, through
> the %c directive, it fails if that character is '\xff'.
>
> Seen with musl libc 1.2.4, in Alpine Linux 3.18.0.
>
> How to reproduce:
> ============================ foo.c ============================
> #include <stdio.h>
> #include <wchar.h>
> int main ()
> {
> wchar_t buf[12];
> for (int c = 1; c < 256; c++)
> {
> fprintf (stderr, "c = %d: ", c);
> int ret = swprintf (buf, 12, L"%c", c);
> if (ret >= 0)
> fprintf (stderr, "OK, %d bytes\n", ret);
> else
> perror ("swprintf failed");
> }
> }
> ===============================================================
> $ gcc -Wall foo.c
> $ ./a.out
>
> Expected output:
> c = 1: OK, 1 bytes
> c = 2: OK, 1 bytes
> c = 3: OK, 1 bytes
> c = 4: OK, 1 bytes
> c = 5: OK, 1 bytes
> c = 6: OK, 1 bytes
> c = 7: OK, 1 bytes
> c = 8: OK, 1 bytes
> c = 9: OK, 1 bytes
> c = 10: OK, 1 bytes
> c = 11: OK, 1 bytes
> c = 12: OK, 1 bytes
> c = 13: OK, 1 bytes
> c = 14: OK, 1 bytes
> c = 15: OK, 1 bytes
> c = 16: OK, 1 bytes
> c = 17: OK, 1 bytes
> c = 18: OK, 1 bytes
> c = 19: OK, 1 bytes
> c = 20: OK, 1 bytes
> c = 21: OK, 1 bytes
> c = 22: OK, 1 bytes
> c = 23: OK, 1 bytes
> c = 24: OK, 1 bytes
> c = 25: OK, 1 bytes
> c = 26: OK, 1 bytes
> c = 27: OK, 1 bytes
> c = 28: OK, 1 bytes
> c = 29: OK, 1 bytes
> c = 30: OK, 1 bytes
> c = 31: OK, 1 bytes
> c = 32: OK, 1 bytes
> c = 33: OK, 1 bytes
> c = 34: OK, 1 bytes
> c = 35: OK, 1 bytes
> c = 36: OK, 1 bytes
> c = 37: OK, 1 bytes
> c = 38: OK, 1 bytes
> c = 39: OK, 1 bytes
> c = 40: OK, 1 bytes
> c = 41: OK, 1 bytes
> c = 42: OK, 1 bytes
> c = 43: OK, 1 bytes
> c = 44: OK, 1 bytes
> c = 45: OK, 1 bytes
> c = 46: OK, 1 bytes
> c = 47: OK, 1 bytes
> c = 48: OK, 1 bytes
> c = 49: OK, 1 bytes
> c = 50: OK, 1 bytes
> c = 51: OK, 1 bytes
> c = 52: OK, 1 bytes
> c = 53: OK, 1 bytes
> c = 54: OK, 1 bytes
> c = 55: OK, 1 bytes
> c = 56: OK, 1 bytes
> c = 57: OK, 1 bytes
> c = 58: OK, 1 bytes
> c = 59: OK, 1 bytes
> c = 60: OK, 1 bytes
> c = 61: OK, 1 bytes
> c = 62: OK, 1 bytes
> c = 63: OK, 1 bytes
> c = 64: OK, 1 bytes
> c = 65: OK, 1 bytes
> c = 66: OK, 1 bytes
> c = 67: OK, 1 bytes
> c = 68: OK, 1 bytes
> c = 69: OK, 1 bytes
> c = 70: OK, 1 bytes
> c = 71: OK, 1 bytes
> c = 72: OK, 1 bytes
> c = 73: OK, 1 bytes
> c = 74: OK, 1 bytes
> c = 75: OK, 1 bytes
> c = 76: OK, 1 bytes
> c = 77: OK, 1 bytes
> c = 78: OK, 1 bytes
> c = 79: OK, 1 bytes
> c = 80: OK, 1 bytes
> c = 81: OK, 1 bytes
> c = 82: OK, 1 bytes
> c = 83: OK, 1 bytes
> c = 84: OK, 1 bytes
> c = 85: OK, 1 bytes
> c = 86: OK, 1 bytes
> c = 87: OK, 1 bytes
> c = 88: OK, 1 bytes
> c = 89: OK, 1 bytes
> c = 90: OK, 1 bytes
> c = 91: OK, 1 bytes
> c = 92: OK, 1 bytes
> c = 93: OK, 1 bytes
> c = 94: OK, 1 bytes
> c = 95: OK, 1 bytes
> c = 96: OK, 1 bytes
> c = 97: OK, 1 bytes
> c = 98: OK, 1 bytes
> c = 99: OK, 1 bytes
> c = 100: OK, 1 bytes
> c = 101: OK, 1 bytes
> c = 102: OK, 1 bytes
> c = 103: OK, 1 bytes
> c = 104: OK, 1 bytes
> c = 105: OK, 1 bytes
> c = 106: OK, 1 bytes
> c = 107: OK, 1 bytes
> c = 108: OK, 1 bytes
> c = 109: OK, 1 bytes
> c = 110: OK, 1 bytes
> c = 111: OK, 1 bytes
> c = 112: OK, 1 bytes
> c = 113: OK, 1 bytes
> c = 114: OK, 1 bytes
> c = 115: OK, 1 bytes
> c = 116: OK, 1 bytes
> c = 117: OK, 1 bytes
> c = 118: OK, 1 bytes
> c = 119: OK, 1 bytes
> c = 120: OK, 1 bytes
> c = 121: OK, 1 bytes
> c = 122: OK, 1 bytes
> c = 123: OK, 1 bytes
> c = 124: OK, 1 bytes
> c = 125: OK, 1 bytes
> c = 126: OK, 1 bytes
> c = 127: OK, 1 bytes
> c = 128: OK, 1 bytes
> c = 129: OK, 1 bytes
> c = 130: OK, 1 bytes
> c = 131: OK, 1 bytes
> c = 132: OK, 1 bytes
> c = 133: OK, 1 bytes
> c = 134: OK, 1 bytes
> c = 135: OK, 1 bytes
> c = 136: OK, 1 bytes
> c = 137: OK, 1 bytes
> c = 138: OK, 1 bytes
> c = 139: OK, 1 bytes
> c = 140: OK, 1 bytes
> c = 141: OK, 1 bytes
> c = 142: OK, 1 bytes
> c = 143: OK, 1 bytes
> c = 144: OK, 1 bytes
> c = 145: OK, 1 bytes
> c = 146: OK, 1 bytes
> c = 147: OK, 1 bytes
> c = 148: OK, 1 bytes
> c = 149: OK, 1 bytes
> c = 150: OK, 1 bytes
> c = 151: OK, 1 bytes
> c = 152: OK, 1 bytes
> c = 153: OK, 1 bytes
> c = 154: OK, 1 bytes
> c = 155: OK, 1 bytes
> c = 156: OK, 1 bytes
> c = 157: OK, 1 bytes
> c = 158: OK, 1 bytes
> c = 159: OK, 1 bytes
> c = 160: OK, 1 bytes
> c = 161: OK, 1 bytes
> c = 162: OK, 1 bytes
> c = 163: OK, 1 bytes
> c = 164: OK, 1 bytes
> c = 165: OK, 1 bytes
> c = 166: OK, 1 bytes
> c = 167: OK, 1 bytes
> c = 168: OK, 1 bytes
> c = 169: OK, 1 bytes
> c = 170: OK, 1 bytes
> c = 171: OK, 1 bytes
> c = 172: OK, 1 bytes
> c = 173: OK, 1 bytes
> c = 174: OK, 1 bytes
> c = 175: OK, 1 bytes
> c = 176: OK, 1 bytes
> c = 177: OK, 1 bytes
> c = 178: OK, 1 bytes
> c = 179: OK, 1 bytes
> c = 180: OK, 1 bytes
> c = 181: OK, 1 bytes
> c = 182: OK, 1 bytes
> c = 183: OK, 1 bytes
> c = 184: OK, 1 bytes
> c = 185: OK, 1 bytes
> c = 186: OK, 1 bytes
> c = 187: OK, 1 bytes
> c = 188: OK, 1 bytes
> c = 189: OK, 1 bytes
> c = 190: OK, 1 bytes
> c = 191: OK, 1 bytes
> c = 192: OK, 1 bytes
> c = 193: OK, 1 bytes
> c = 194: OK, 1 bytes
> c = 195: OK, 1 bytes
> c = 196: OK, 1 bytes
> c = 197: OK, 1 bytes
> c = 198: OK, 1 bytes
> c = 199: OK, 1 bytes
> c = 200: OK, 1 bytes
> c = 201: OK, 1 bytes
> c = 202: OK, 1 bytes
> c = 203: OK, 1 bytes
> c = 204: OK, 1 bytes
> c = 205: OK, 1 bytes
> c = 206: OK, 1 bytes
> c = 207: OK, 1 bytes
> c = 208: OK, 1 bytes
> c = 209: OK, 1 bytes
> c = 210: OK, 1 bytes
> c = 211: OK, 1 bytes
> c = 212: OK, 1 bytes
> c = 213: OK, 1 bytes
> c = 214: OK, 1 bytes
> c = 215: OK, 1 bytes
> c = 216: OK, 1 bytes
> c = 217: OK, 1 bytes
> c = 218: OK, 1 bytes
> c = 219: OK, 1 bytes
> c = 220: OK, 1 bytes
> c = 221: OK, 1 bytes
> c = 222: OK, 1 bytes
> c = 223: OK, 1 bytes
> c = 224: OK, 1 bytes
> c = 225: OK, 1 bytes
> c = 226: OK, 1 bytes
> c = 227: OK, 1 bytes
> c = 228: OK, 1 bytes
> c = 229: OK, 1 bytes
> c = 230: OK, 1 bytes
> c = 231: OK, 1 bytes
> c = 232: OK, 1 bytes
> c = 233: OK, 1 bytes
> c = 234: OK, 1 bytes
> c = 235: OK, 1 bytes
> c = 236: OK, 1 bytes
> c = 237: OK, 1 bytes
> c = 238: OK, 1 bytes
> c = 239: OK, 1 bytes
> c = 240: OK, 1 bytes
> c = 241: OK, 1 bytes
> c = 242: OK, 1 bytes
> c = 243: OK, 1 bytes
> c = 244: OK, 1 bytes
> c = 245: OK, 1 bytes
> c = 246: OK, 1 bytes
> c = 247: OK, 1 bytes
> c = 248: OK, 1 bytes
> c = 249: OK, 1 bytes
> c = 250: OK, 1 bytes
> c = 251: OK, 1 bytes
> c = 252: OK, 1 bytes
> c = 253: OK, 1 bytes
> c = 254: OK, 1 bytes
> c = 255: OK, 1 bytes
>
> Actual output:
> c = 1: OK, 1 bytes
> c = 2: OK, 1 bytes
> c = 3: OK, 1 bytes
> c = 4: OK, 1 bytes
> c = 5: OK, 1 bytes
> c = 6: OK, 1 bytes
> c = 7: OK, 1 bytes
> c = 8: OK, 1 bytes
> c = 9: OK, 1 bytes
> c = 10: OK, 1 bytes
> c = 11: OK, 1 bytes
> c = 12: OK, 1 bytes
> c = 13: OK, 1 bytes
> c = 14: OK, 1 bytes
> c = 15: OK, 1 bytes
> c = 16: OK, 1 bytes
> c = 17: OK, 1 bytes
> c = 18: OK, 1 bytes
> c = 19: OK, 1 bytes
> c = 20: OK, 1 bytes
> c = 21: OK, 1 bytes
> c = 22: OK, 1 bytes
> c = 23: OK, 1 bytes
> c = 24: OK, 1 bytes
> c = 25: OK, 1 bytes
> c = 26: OK, 1 bytes
> c = 27: OK, 1 bytes
> c = 28: OK, 1 bytes
> c = 29: OK, 1 bytes
> c = 30: OK, 1 bytes
> c = 31: OK, 1 bytes
> c = 32: OK, 1 bytes
> c = 33: OK, 1 bytes
> c = 34: OK, 1 bytes
> c = 35: OK, 1 bytes
> c = 36: OK, 1 bytes
> c = 37: OK, 1 bytes
> c = 38: OK, 1 bytes
> c = 39: OK, 1 bytes
> c = 40: OK, 1 bytes
> c = 41: OK, 1 bytes
> c = 42: OK, 1 bytes
> c = 43: OK, 1 bytes
> c = 44: OK, 1 bytes
> c = 45: OK, 1 bytes
> c = 46: OK, 1 bytes
> c = 47: OK, 1 bytes
> c = 48: OK, 1 bytes
> c = 49: OK, 1 bytes
> c = 50: OK, 1 bytes
> c = 51: OK, 1 bytes
> c = 52: OK, 1 bytes
> c = 53: OK, 1 bytes
> c = 54: OK, 1 bytes
> c = 55: OK, 1 bytes
> c = 56: OK, 1 bytes
> c = 57: OK, 1 bytes
> c = 58: OK, 1 bytes
> c = 59: OK, 1 bytes
> c = 60: OK, 1 bytes
> c = 61: OK, 1 bytes
> c = 62: OK, 1 bytes
> c = 63: OK, 1 bytes
> c = 64: OK, 1 bytes
> c = 65: OK, 1 bytes
> c = 66: OK, 1 bytes
> c = 67: OK, 1 bytes
> c = 68: OK, 1 bytes
> c = 69: OK, 1 bytes
> c = 70: OK, 1 bytes
> c = 71: OK, 1 bytes
> c = 72: OK, 1 bytes
> c = 73: OK, 1 bytes
> c = 74: OK, 1 bytes
> c = 75: OK, 1 bytes
> c = 76: OK, 1 bytes
> c = 77: OK, 1 bytes
> c = 78: OK, 1 bytes
> c = 79: OK, 1 bytes
> c = 80: OK, 1 bytes
> c = 81: OK, 1 bytes
> c = 82: OK, 1 bytes
> c = 83: OK, 1 bytes
> c = 84: OK, 1 bytes
> c = 85: OK, 1 bytes
> c = 86: OK, 1 bytes
> c = 87: OK, 1 bytes
> c = 88: OK, 1 bytes
> c = 89: OK, 1 bytes
> c = 90: OK, 1 bytes
> c = 91: OK, 1 bytes
> c = 92: OK, 1 bytes
> c = 93: OK, 1 bytes
> c = 94: OK, 1 bytes
> c = 95: OK, 1 bytes
> c = 96: OK, 1 bytes
> c = 97: OK, 1 bytes
> c = 98: OK, 1 bytes
> c = 99: OK, 1 bytes
> c = 100: OK, 1 bytes
> c = 101: OK, 1 bytes
> c = 102: OK, 1 bytes
> c = 103: OK, 1 bytes
> c = 104: OK, 1 bytes
> c = 105: OK, 1 bytes
> c = 106: OK, 1 bytes
> c = 107: OK, 1 bytes
> c = 108: OK, 1 bytes
> c = 109: OK, 1 bytes
> c = 110: OK, 1 bytes
> c = 111: OK, 1 bytes
> c = 112: OK, 1 bytes
> c = 113: OK, 1 bytes
> c = 114: OK, 1 bytes
> c = 115: OK, 1 bytes
> c = 116: OK, 1 bytes
> c = 117: OK, 1 bytes
> c = 118: OK, 1 bytes
> c = 119: OK, 1 bytes
> c = 120: OK, 1 bytes
> c = 121: OK, 1 bytes
> c = 122: OK, 1 bytes
> c = 123: OK, 1 bytes
> c = 124: OK, 1 bytes
> c = 125: OK, 1 bytes
> c = 126: OK, 1 bytes
> c = 127: OK, 1 bytes
> c = 128: OK, 1 bytes
> c = 129: OK, 1 bytes
> c = 130: OK, 1 bytes
> c = 131: OK, 1 bytes
> c = 132: OK, 1 bytes
> c = 133: OK, 1 bytes
> c = 134: OK, 1 bytes
> c = 135: OK, 1 bytes
> c = 136: OK, 1 bytes
> c = 137: OK, 1 bytes
> c = 138: OK, 1 bytes
> c = 139: OK, 1 bytes
> c = 140: OK, 1 bytes
> c = 141: OK, 1 bytes
> c = 142: OK, 1 bytes
> c = 143: OK, 1 bytes
> c = 144: OK, 1 bytes
> c = 145: OK, 1 bytes
> c = 146: OK, 1 bytes
> c = 147: OK, 1 bytes
> c = 148: OK, 1 bytes
> c = 149: OK, 1 bytes
> c = 150: OK, 1 bytes
> c = 151: OK, 1 bytes
> c = 152: OK, 1 bytes
> c = 153: OK, 1 bytes
> c = 154: OK, 1 bytes
> c = 155: OK, 1 bytes
> c = 156: OK, 1 bytes
> c = 157: OK, 1 bytes
> c = 158: OK, 1 bytes
> c = 159: OK, 1 bytes
> c = 160: OK, 1 bytes
> c = 161: OK, 1 bytes
> c = 162: OK, 1 bytes
> c = 163: OK, 1 bytes
> c = 164: OK, 1 bytes
> c = 165: OK, 1 bytes
> c = 166: OK, 1 bytes
> c = 167: OK, 1 bytes
> c = 168: OK, 1 bytes
> c = 169: OK, 1 bytes
> c = 170: OK, 1 bytes
> c = 171: OK, 1 bytes
> c = 172: OK, 1 bytes
> c = 173: OK, 1 bytes
> c = 174: OK, 1 bytes
> c = 175: OK, 1 bytes
> c = 176: OK, 1 bytes
> c = 177: OK, 1 bytes
> c = 178: OK, 1 bytes
> c = 179: OK, 1 bytes
> c = 180: OK, 1 bytes
> c = 181: OK, 1 bytes
> c = 182: OK, 1 bytes
> c = 183: OK, 1 bytes
> c = 184: OK, 1 bytes
> c = 185: OK, 1 bytes
> c = 186: OK, 1 bytes
> c = 187: OK, 1 bytes
> c = 188: OK, 1 bytes
> c = 189: OK, 1 bytes
> c = 190: OK, 1 bytes
> c = 191: OK, 1 bytes
> c = 192: OK, 1 bytes
> c = 193: OK, 1 bytes
> c = 194: OK, 1 bytes
> c = 195: OK, 1 bytes
> c = 196: OK, 1 bytes
> c = 197: OK, 1 bytes
> c = 198: OK, 1 bytes
> c = 199: OK, 1 bytes
> c = 200: OK, 1 bytes
> c = 201: OK, 1 bytes
> c = 202: OK, 1 bytes
> c = 203: OK, 1 bytes
> c = 204: OK, 1 bytes
> c = 205: OK, 1 bytes
> c = 206: OK, 1 bytes
> c = 207: OK, 1 bytes
> c = 208: OK, 1 bytes
> c = 209: OK, 1 bytes
> c = 210: OK, 1 bytes
> c = 211: OK, 1 bytes
> c = 212: OK, 1 bytes
> c = 213: OK, 1 bytes
> c = 214: OK, 1 bytes
> c = 215: OK, 1 bytes
> c = 216: OK, 1 bytes
> c = 217: OK, 1 bytes
> c = 218: OK, 1 bytes
> c = 219: OK, 1 bytes
> c = 220: OK, 1 bytes
> c = 221: OK, 1 bytes
> c = 222: OK, 1 bytes
> c = 223: OK, 1 bytes
> c = 224: OK, 1 bytes
> c = 225: OK, 1 bytes
> c = 226: OK, 1 bytes
> c = 227: OK, 1 bytes
> c = 228: OK, 1 bytes
> c = 229: OK, 1 bytes
> c = 230: OK, 1 bytes
> c = 231: OK, 1 bytes
> c = 232: OK, 1 bytes
> c = 233: OK, 1 bytes
> c = 234: OK, 1 bytes
> c = 235: OK, 1 bytes
> c = 236: OK, 1 bytes
> c = 237: OK, 1 bytes
> c = 238: OK, 1 bytes
> c = 239: OK, 1 bytes
> c = 240: OK, 1 bytes
> c = 241: OK, 1 bytes
> c = 242: OK, 1 bytes
> c = 243: OK, 1 bytes
> c = 244: OK, 1 bytes
> c = 245: OK, 1 bytes
> c = 246: OK, 1 bytes
> c = 247: OK, 1 bytes
> c = 248: OK, 1 bytes
> c = 249: OK, 1 bytes
> c = 250: OK, 1 bytes
> c = 251: OK, 1 bytes
> c = 252: OK, 1 bytes
> c = 253: OK, 1 bytes
> c = 254: OK, 1 bytes
> c = 255: swprintf failed: Illegal byte sequence
>
> This is a bug, because POSIX says that in the C / POSIX locale, "all byte
> values are valid characters" [1].
Yes, this is a bug and seems to be an instance of mishandling of
signed conversions. Attached should correct it.
Rich
[-- Attachment #2: wprintf-255.diff --]
[-- Type: text/plain, Size: 478 bytes --]
diff --git a/src/stdio/vfwprintf.c b/src/stdio/vfwprintf.c
index 53697701..a653e233 100644
--- a/src/stdio/vfwprintf.c
+++ b/src/stdio/vfwprintf.c
@@ -271,7 +271,7 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_
case 'C':
if (w<1) w=1;
pad(f, w-1, fl);
- out(f, &(wchar_t){t=='C' ? arg.i : btowc(arg.i)}, 1);
+ out(f, &(wchar_t){t=='C' ? arg.i : btowc(arg.i & 0xff)}, 1);
pad(f, w-1, fl^LEFT_ADJ);
l = w;
continue;
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [musl] swprintf cannot handle the character 0xff
2023-06-12 20:22 ` Rich Felker
@ 2023-06-12 21:01 ` Rich Felker
2023-06-12 21:13 ` Rich Felker
0 siblings, 1 reply; 7+ messages in thread
From: Rich Felker @ 2023-06-12 21:01 UTC (permalink / raw)
To: Bruno Haible; +Cc: musl
On Mon, Jun 12, 2023 at 04:22:42PM -0400, Rich Felker wrote:
> On Mon, Jun 12, 2023 at 02:30:44PM +0200, Bruno Haible wrote:
> > When swprintf is meant to convert a character to a wide character, through
> > the %c directive, it fails if that character is '\xff'.
> >
> > Seen with musl libc 1.2.4, in Alpine Linux 3.18.0.
> >
> > How to reproduce:
> > ============================ foo.c ============================
> > #include <stdio.h>
> > #include <wchar.h>
> > int main ()
> > {
> > wchar_t buf[12];
> > for (int c = 1; c < 256; c++)
> > {
> > fprintf (stderr, "c = %d: ", c);
> > int ret = swprintf (buf, 12, L"%c", c);
> > if (ret >= 0)
> > fprintf (stderr, "OK, %d bytes\n", ret);
> > else
> > perror ("swprintf failed");
> > }
> > }
> > ===============================================================
> > $ gcc -Wall foo.c
> > $ ./a.out
> >
> > Expected output:
> > c = 1: OK, 1 bytes
> > c = 2: OK, 1 bytes
> > c = 3: OK, 1 bytes
> > c = 4: OK, 1 bytes
> > c = 5: OK, 1 bytes
> > c = 6: OK, 1 bytes
> > c = 7: OK, 1 bytes
> > c = 8: OK, 1 bytes
> > c = 9: OK, 1 bytes
> > c = 10: OK, 1 bytes
> > c = 11: OK, 1 bytes
> > c = 12: OK, 1 bytes
> > c = 13: OK, 1 bytes
> > c = 14: OK, 1 bytes
> > c = 15: OK, 1 bytes
> > c = 16: OK, 1 bytes
> > c = 17: OK, 1 bytes
> > c = 18: OK, 1 bytes
> > c = 19: OK, 1 bytes
> > c = 20: OK, 1 bytes
> > c = 21: OK, 1 bytes
> > c = 22: OK, 1 bytes
> > c = 23: OK, 1 bytes
> > c = 24: OK, 1 bytes
> > c = 25: OK, 1 bytes
> > c = 26: OK, 1 bytes
> > c = 27: OK, 1 bytes
> > c = 28: OK, 1 bytes
> > c = 29: OK, 1 bytes
> > c = 30: OK, 1 bytes
> > c = 31: OK, 1 bytes
> > c = 32: OK, 1 bytes
> > c = 33: OK, 1 bytes
> > c = 34: OK, 1 bytes
> > c = 35: OK, 1 bytes
> > c = 36: OK, 1 bytes
> > c = 37: OK, 1 bytes
> > c = 38: OK, 1 bytes
> > c = 39: OK, 1 bytes
> > c = 40: OK, 1 bytes
> > c = 41: OK, 1 bytes
> > c = 42: OK, 1 bytes
> > c = 43: OK, 1 bytes
> > c = 44: OK, 1 bytes
> > c = 45: OK, 1 bytes
> > c = 46: OK, 1 bytes
> > c = 47: OK, 1 bytes
> > c = 48: OK, 1 bytes
> > c = 49: OK, 1 bytes
> > c = 50: OK, 1 bytes
> > c = 51: OK, 1 bytes
> > c = 52: OK, 1 bytes
> > c = 53: OK, 1 bytes
> > c = 54: OK, 1 bytes
> > c = 55: OK, 1 bytes
> > c = 56: OK, 1 bytes
> > c = 57: OK, 1 bytes
> > c = 58: OK, 1 bytes
> > c = 59: OK, 1 bytes
> > c = 60: OK, 1 bytes
> > c = 61: OK, 1 bytes
> > c = 62: OK, 1 bytes
> > c = 63: OK, 1 bytes
> > c = 64: OK, 1 bytes
> > c = 65: OK, 1 bytes
> > c = 66: OK, 1 bytes
> > c = 67: OK, 1 bytes
> > c = 68: OK, 1 bytes
> > c = 69: OK, 1 bytes
> > c = 70: OK, 1 bytes
> > c = 71: OK, 1 bytes
> > c = 72: OK, 1 bytes
> > c = 73: OK, 1 bytes
> > c = 74: OK, 1 bytes
> > c = 75: OK, 1 bytes
> > c = 76: OK, 1 bytes
> > c = 77: OK, 1 bytes
> > c = 78: OK, 1 bytes
> > c = 79: OK, 1 bytes
> > c = 80: OK, 1 bytes
> > c = 81: OK, 1 bytes
> > c = 82: OK, 1 bytes
> > c = 83: OK, 1 bytes
> > c = 84: OK, 1 bytes
> > c = 85: OK, 1 bytes
> > c = 86: OK, 1 bytes
> > c = 87: OK, 1 bytes
> > c = 88: OK, 1 bytes
> > c = 89: OK, 1 bytes
> > c = 90: OK, 1 bytes
> > c = 91: OK, 1 bytes
> > c = 92: OK, 1 bytes
> > c = 93: OK, 1 bytes
> > c = 94: OK, 1 bytes
> > c = 95: OK, 1 bytes
> > c = 96: OK, 1 bytes
> > c = 97: OK, 1 bytes
> > c = 98: OK, 1 bytes
> > c = 99: OK, 1 bytes
> > c = 100: OK, 1 bytes
> > c = 101: OK, 1 bytes
> > c = 102: OK, 1 bytes
> > c = 103: OK, 1 bytes
> > c = 104: OK, 1 bytes
> > c = 105: OK, 1 bytes
> > c = 106: OK, 1 bytes
> > c = 107: OK, 1 bytes
> > c = 108: OK, 1 bytes
> > c = 109: OK, 1 bytes
> > c = 110: OK, 1 bytes
> > c = 111: OK, 1 bytes
> > c = 112: OK, 1 bytes
> > c = 113: OK, 1 bytes
> > c = 114: OK, 1 bytes
> > c = 115: OK, 1 bytes
> > c = 116: OK, 1 bytes
> > c = 117: OK, 1 bytes
> > c = 118: OK, 1 bytes
> > c = 119: OK, 1 bytes
> > c = 120: OK, 1 bytes
> > c = 121: OK, 1 bytes
> > c = 122: OK, 1 bytes
> > c = 123: OK, 1 bytes
> > c = 124: OK, 1 bytes
> > c = 125: OK, 1 bytes
> > c = 126: OK, 1 bytes
> > c = 127: OK, 1 bytes
> > c = 128: OK, 1 bytes
> > c = 129: OK, 1 bytes
> > c = 130: OK, 1 bytes
> > c = 131: OK, 1 bytes
> > c = 132: OK, 1 bytes
> > c = 133: OK, 1 bytes
> > c = 134: OK, 1 bytes
> > c = 135: OK, 1 bytes
> > c = 136: OK, 1 bytes
> > c = 137: OK, 1 bytes
> > c = 138: OK, 1 bytes
> > c = 139: OK, 1 bytes
> > c = 140: OK, 1 bytes
> > c = 141: OK, 1 bytes
> > c = 142: OK, 1 bytes
> > c = 143: OK, 1 bytes
> > c = 144: OK, 1 bytes
> > c = 145: OK, 1 bytes
> > c = 146: OK, 1 bytes
> > c = 147: OK, 1 bytes
> > c = 148: OK, 1 bytes
> > c = 149: OK, 1 bytes
> > c = 150: OK, 1 bytes
> > c = 151: OK, 1 bytes
> > c = 152: OK, 1 bytes
> > c = 153: OK, 1 bytes
> > c = 154: OK, 1 bytes
> > c = 155: OK, 1 bytes
> > c = 156: OK, 1 bytes
> > c = 157: OK, 1 bytes
> > c = 158: OK, 1 bytes
> > c = 159: OK, 1 bytes
> > c = 160: OK, 1 bytes
> > c = 161: OK, 1 bytes
> > c = 162: OK, 1 bytes
> > c = 163: OK, 1 bytes
> > c = 164: OK, 1 bytes
> > c = 165: OK, 1 bytes
> > c = 166: OK, 1 bytes
> > c = 167: OK, 1 bytes
> > c = 168: OK, 1 bytes
> > c = 169: OK, 1 bytes
> > c = 170: OK, 1 bytes
> > c = 171: OK, 1 bytes
> > c = 172: OK, 1 bytes
> > c = 173: OK, 1 bytes
> > c = 174: OK, 1 bytes
> > c = 175: OK, 1 bytes
> > c = 176: OK, 1 bytes
> > c = 177: OK, 1 bytes
> > c = 178: OK, 1 bytes
> > c = 179: OK, 1 bytes
> > c = 180: OK, 1 bytes
> > c = 181: OK, 1 bytes
> > c = 182: OK, 1 bytes
> > c = 183: OK, 1 bytes
> > c = 184: OK, 1 bytes
> > c = 185: OK, 1 bytes
> > c = 186: OK, 1 bytes
> > c = 187: OK, 1 bytes
> > c = 188: OK, 1 bytes
> > c = 189: OK, 1 bytes
> > c = 190: OK, 1 bytes
> > c = 191: OK, 1 bytes
> > c = 192: OK, 1 bytes
> > c = 193: OK, 1 bytes
> > c = 194: OK, 1 bytes
> > c = 195: OK, 1 bytes
> > c = 196: OK, 1 bytes
> > c = 197: OK, 1 bytes
> > c = 198: OK, 1 bytes
> > c = 199: OK, 1 bytes
> > c = 200: OK, 1 bytes
> > c = 201: OK, 1 bytes
> > c = 202: OK, 1 bytes
> > c = 203: OK, 1 bytes
> > c = 204: OK, 1 bytes
> > c = 205: OK, 1 bytes
> > c = 206: OK, 1 bytes
> > c = 207: OK, 1 bytes
> > c = 208: OK, 1 bytes
> > c = 209: OK, 1 bytes
> > c = 210: OK, 1 bytes
> > c = 211: OK, 1 bytes
> > c = 212: OK, 1 bytes
> > c = 213: OK, 1 bytes
> > c = 214: OK, 1 bytes
> > c = 215: OK, 1 bytes
> > c = 216: OK, 1 bytes
> > c = 217: OK, 1 bytes
> > c = 218: OK, 1 bytes
> > c = 219: OK, 1 bytes
> > c = 220: OK, 1 bytes
> > c = 221: OK, 1 bytes
> > c = 222: OK, 1 bytes
> > c = 223: OK, 1 bytes
> > c = 224: OK, 1 bytes
> > c = 225: OK, 1 bytes
> > c = 226: OK, 1 bytes
> > c = 227: OK, 1 bytes
> > c = 228: OK, 1 bytes
> > c = 229: OK, 1 bytes
> > c = 230: OK, 1 bytes
> > c = 231: OK, 1 bytes
> > c = 232: OK, 1 bytes
> > c = 233: OK, 1 bytes
> > c = 234: OK, 1 bytes
> > c = 235: OK, 1 bytes
> > c = 236: OK, 1 bytes
> > c = 237: OK, 1 bytes
> > c = 238: OK, 1 bytes
> > c = 239: OK, 1 bytes
> > c = 240: OK, 1 bytes
> > c = 241: OK, 1 bytes
> > c = 242: OK, 1 bytes
> > c = 243: OK, 1 bytes
> > c = 244: OK, 1 bytes
> > c = 245: OK, 1 bytes
> > c = 246: OK, 1 bytes
> > c = 247: OK, 1 bytes
> > c = 248: OK, 1 bytes
> > c = 249: OK, 1 bytes
> > c = 250: OK, 1 bytes
> > c = 251: OK, 1 bytes
> > c = 252: OK, 1 bytes
> > c = 253: OK, 1 bytes
> > c = 254: OK, 1 bytes
> > c = 255: OK, 1 bytes
> >
> > Actual output:
> > c = 1: OK, 1 bytes
> > c = 2: OK, 1 bytes
> > c = 3: OK, 1 bytes
> > c = 4: OK, 1 bytes
> > c = 5: OK, 1 bytes
> > c = 6: OK, 1 bytes
> > c = 7: OK, 1 bytes
> > c = 8: OK, 1 bytes
> > c = 9: OK, 1 bytes
> > c = 10: OK, 1 bytes
> > c = 11: OK, 1 bytes
> > c = 12: OK, 1 bytes
> > c = 13: OK, 1 bytes
> > c = 14: OK, 1 bytes
> > c = 15: OK, 1 bytes
> > c = 16: OK, 1 bytes
> > c = 17: OK, 1 bytes
> > c = 18: OK, 1 bytes
> > c = 19: OK, 1 bytes
> > c = 20: OK, 1 bytes
> > c = 21: OK, 1 bytes
> > c = 22: OK, 1 bytes
> > c = 23: OK, 1 bytes
> > c = 24: OK, 1 bytes
> > c = 25: OK, 1 bytes
> > c = 26: OK, 1 bytes
> > c = 27: OK, 1 bytes
> > c = 28: OK, 1 bytes
> > c = 29: OK, 1 bytes
> > c = 30: OK, 1 bytes
> > c = 31: OK, 1 bytes
> > c = 32: OK, 1 bytes
> > c = 33: OK, 1 bytes
> > c = 34: OK, 1 bytes
> > c = 35: OK, 1 bytes
> > c = 36: OK, 1 bytes
> > c = 37: OK, 1 bytes
> > c = 38: OK, 1 bytes
> > c = 39: OK, 1 bytes
> > c = 40: OK, 1 bytes
> > c = 41: OK, 1 bytes
> > c = 42: OK, 1 bytes
> > c = 43: OK, 1 bytes
> > c = 44: OK, 1 bytes
> > c = 45: OK, 1 bytes
> > c = 46: OK, 1 bytes
> > c = 47: OK, 1 bytes
> > c = 48: OK, 1 bytes
> > c = 49: OK, 1 bytes
> > c = 50: OK, 1 bytes
> > c = 51: OK, 1 bytes
> > c = 52: OK, 1 bytes
> > c = 53: OK, 1 bytes
> > c = 54: OK, 1 bytes
> > c = 55: OK, 1 bytes
> > c = 56: OK, 1 bytes
> > c = 57: OK, 1 bytes
> > c = 58: OK, 1 bytes
> > c = 59: OK, 1 bytes
> > c = 60: OK, 1 bytes
> > c = 61: OK, 1 bytes
> > c = 62: OK, 1 bytes
> > c = 63: OK, 1 bytes
> > c = 64: OK, 1 bytes
> > c = 65: OK, 1 bytes
> > c = 66: OK, 1 bytes
> > c = 67: OK, 1 bytes
> > c = 68: OK, 1 bytes
> > c = 69: OK, 1 bytes
> > c = 70: OK, 1 bytes
> > c = 71: OK, 1 bytes
> > c = 72: OK, 1 bytes
> > c = 73: OK, 1 bytes
> > c = 74: OK, 1 bytes
> > c = 75: OK, 1 bytes
> > c = 76: OK, 1 bytes
> > c = 77: OK, 1 bytes
> > c = 78: OK, 1 bytes
> > c = 79: OK, 1 bytes
> > c = 80: OK, 1 bytes
> > c = 81: OK, 1 bytes
> > c = 82: OK, 1 bytes
> > c = 83: OK, 1 bytes
> > c = 84: OK, 1 bytes
> > c = 85: OK, 1 bytes
> > c = 86: OK, 1 bytes
> > c = 87: OK, 1 bytes
> > c = 88: OK, 1 bytes
> > c = 89: OK, 1 bytes
> > c = 90: OK, 1 bytes
> > c = 91: OK, 1 bytes
> > c = 92: OK, 1 bytes
> > c = 93: OK, 1 bytes
> > c = 94: OK, 1 bytes
> > c = 95: OK, 1 bytes
> > c = 96: OK, 1 bytes
> > c = 97: OK, 1 bytes
> > c = 98: OK, 1 bytes
> > c = 99: OK, 1 bytes
> > c = 100: OK, 1 bytes
> > c = 101: OK, 1 bytes
> > c = 102: OK, 1 bytes
> > c = 103: OK, 1 bytes
> > c = 104: OK, 1 bytes
> > c = 105: OK, 1 bytes
> > c = 106: OK, 1 bytes
> > c = 107: OK, 1 bytes
> > c = 108: OK, 1 bytes
> > c = 109: OK, 1 bytes
> > c = 110: OK, 1 bytes
> > c = 111: OK, 1 bytes
> > c = 112: OK, 1 bytes
> > c = 113: OK, 1 bytes
> > c = 114: OK, 1 bytes
> > c = 115: OK, 1 bytes
> > c = 116: OK, 1 bytes
> > c = 117: OK, 1 bytes
> > c = 118: OK, 1 bytes
> > c = 119: OK, 1 bytes
> > c = 120: OK, 1 bytes
> > c = 121: OK, 1 bytes
> > c = 122: OK, 1 bytes
> > c = 123: OK, 1 bytes
> > c = 124: OK, 1 bytes
> > c = 125: OK, 1 bytes
> > c = 126: OK, 1 bytes
> > c = 127: OK, 1 bytes
> > c = 128: OK, 1 bytes
> > c = 129: OK, 1 bytes
> > c = 130: OK, 1 bytes
> > c = 131: OK, 1 bytes
> > c = 132: OK, 1 bytes
> > c = 133: OK, 1 bytes
> > c = 134: OK, 1 bytes
> > c = 135: OK, 1 bytes
> > c = 136: OK, 1 bytes
> > c = 137: OK, 1 bytes
> > c = 138: OK, 1 bytes
> > c = 139: OK, 1 bytes
> > c = 140: OK, 1 bytes
> > c = 141: OK, 1 bytes
> > c = 142: OK, 1 bytes
> > c = 143: OK, 1 bytes
> > c = 144: OK, 1 bytes
> > c = 145: OK, 1 bytes
> > c = 146: OK, 1 bytes
> > c = 147: OK, 1 bytes
> > c = 148: OK, 1 bytes
> > c = 149: OK, 1 bytes
> > c = 150: OK, 1 bytes
> > c = 151: OK, 1 bytes
> > c = 152: OK, 1 bytes
> > c = 153: OK, 1 bytes
> > c = 154: OK, 1 bytes
> > c = 155: OK, 1 bytes
> > c = 156: OK, 1 bytes
> > c = 157: OK, 1 bytes
> > c = 158: OK, 1 bytes
> > c = 159: OK, 1 bytes
> > c = 160: OK, 1 bytes
> > c = 161: OK, 1 bytes
> > c = 162: OK, 1 bytes
> > c = 163: OK, 1 bytes
> > c = 164: OK, 1 bytes
> > c = 165: OK, 1 bytes
> > c = 166: OK, 1 bytes
> > c = 167: OK, 1 bytes
> > c = 168: OK, 1 bytes
> > c = 169: OK, 1 bytes
> > c = 170: OK, 1 bytes
> > c = 171: OK, 1 bytes
> > c = 172: OK, 1 bytes
> > c = 173: OK, 1 bytes
> > c = 174: OK, 1 bytes
> > c = 175: OK, 1 bytes
> > c = 176: OK, 1 bytes
> > c = 177: OK, 1 bytes
> > c = 178: OK, 1 bytes
> > c = 179: OK, 1 bytes
> > c = 180: OK, 1 bytes
> > c = 181: OK, 1 bytes
> > c = 182: OK, 1 bytes
> > c = 183: OK, 1 bytes
> > c = 184: OK, 1 bytes
> > c = 185: OK, 1 bytes
> > c = 186: OK, 1 bytes
> > c = 187: OK, 1 bytes
> > c = 188: OK, 1 bytes
> > c = 189: OK, 1 bytes
> > c = 190: OK, 1 bytes
> > c = 191: OK, 1 bytes
> > c = 192: OK, 1 bytes
> > c = 193: OK, 1 bytes
> > c = 194: OK, 1 bytes
> > c = 195: OK, 1 bytes
> > c = 196: OK, 1 bytes
> > c = 197: OK, 1 bytes
> > c = 198: OK, 1 bytes
> > c = 199: OK, 1 bytes
> > c = 200: OK, 1 bytes
> > c = 201: OK, 1 bytes
> > c = 202: OK, 1 bytes
> > c = 203: OK, 1 bytes
> > c = 204: OK, 1 bytes
> > c = 205: OK, 1 bytes
> > c = 206: OK, 1 bytes
> > c = 207: OK, 1 bytes
> > c = 208: OK, 1 bytes
> > c = 209: OK, 1 bytes
> > c = 210: OK, 1 bytes
> > c = 211: OK, 1 bytes
> > c = 212: OK, 1 bytes
> > c = 213: OK, 1 bytes
> > c = 214: OK, 1 bytes
> > c = 215: OK, 1 bytes
> > c = 216: OK, 1 bytes
> > c = 217: OK, 1 bytes
> > c = 218: OK, 1 bytes
> > c = 219: OK, 1 bytes
> > c = 220: OK, 1 bytes
> > c = 221: OK, 1 bytes
> > c = 222: OK, 1 bytes
> > c = 223: OK, 1 bytes
> > c = 224: OK, 1 bytes
> > c = 225: OK, 1 bytes
> > c = 226: OK, 1 bytes
> > c = 227: OK, 1 bytes
> > c = 228: OK, 1 bytes
> > c = 229: OK, 1 bytes
> > c = 230: OK, 1 bytes
> > c = 231: OK, 1 bytes
> > c = 232: OK, 1 bytes
> > c = 233: OK, 1 bytes
> > c = 234: OK, 1 bytes
> > c = 235: OK, 1 bytes
> > c = 236: OK, 1 bytes
> > c = 237: OK, 1 bytes
> > c = 238: OK, 1 bytes
> > c = 239: OK, 1 bytes
> > c = 240: OK, 1 bytes
> > c = 241: OK, 1 bytes
> > c = 242: OK, 1 bytes
> > c = 243: OK, 1 bytes
> > c = 244: OK, 1 bytes
> > c = 245: OK, 1 bytes
> > c = 246: OK, 1 bytes
> > c = 247: OK, 1 bytes
> > c = 248: OK, 1 bytes
> > c = 249: OK, 1 bytes
> > c = 250: OK, 1 bytes
> > c = 251: OK, 1 bytes
> > c = 252: OK, 1 bytes
> > c = 253: OK, 1 bytes
> > c = 254: OK, 1 bytes
> > c = 255: swprintf failed: Illegal byte sequence
> >
> > This is a bug, because POSIX says that in the C / POSIX locale, "all byte
> > values are valid characters" [1].
>
> Yes, this is a bug and seems to be an instance of mishandling of
> signed conversions. Attached should correct it.
>
> Rich
> diff --git a/src/stdio/vfwprintf.c b/src/stdio/vfwprintf.c
> index 53697701..a653e233 100644
> --- a/src/stdio/vfwprintf.c
> +++ b/src/stdio/vfwprintf.c
> @@ -271,7 +271,7 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_
> case 'C':
> if (w<1) w=1;
> pad(f, w-1, fl);
> - out(f, &(wchar_t){t=='C' ? arg.i : btowc(arg.i)}, 1);
> + out(f, &(wchar_t){t=='C' ? arg.i : btowc(arg.i & 0xff)}, 1);
> pad(f, w-1, fl^LEFT_ADJ);
> l = w;
> continue;
Hmm -- while this works, formally, %c takes an argument of type int
not char, so I think we should probably actually change the state
machine for both narrow and wide printf to terminate with state INT
rather than CHAR for 'c'. And likewise, %lc/%C takes wint_t, which has
type unsigned, so although it doesn't matter the state machine should
terminate with state UINT rather than INT (wint_t is unsigned).
Rich
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [musl] swprintf cannot handle the character 0xff
2023-06-12 21:01 ` Rich Felker
@ 2023-06-12 21:13 ` Rich Felker
2023-06-12 23:09 ` Bruno Haible
0 siblings, 1 reply; 7+ messages in thread
From: Rich Felker @ 2023-06-12 21:13 UTC (permalink / raw)
To: Bruno Haible; +Cc: musl
On Mon, Jun 12, 2023 at 05:01:59PM -0400, Rich Felker wrote:
> On Mon, Jun 12, 2023 at 04:22:42PM -0400, Rich Felker wrote:
> > On Mon, Jun 12, 2023 at 02:30:44PM +0200, Bruno Haible wrote:
> > > When swprintf is meant to convert a character to a wide character, through
> > > the %c directive, it fails if that character is '\xff'.
> > >
> > > Seen with musl libc 1.2.4, in Alpine Linux 3.18.0.
> > >
> > > How to reproduce:
> > > ============================ foo.c ============================
> > > #include <stdio.h>
> > > #include <wchar.h>
> > > int main ()
> > > {
> > > wchar_t buf[12];
> > > for (int c = 1; c < 256; c++)
> > > {
> > > fprintf (stderr, "c = %d: ", c);
> > > int ret = swprintf (buf, 12, L"%c", c);
> > > if (ret >= 0)
> > > fprintf (stderr, "OK, %d bytes\n", ret);
> > > else
> > > perror ("swprintf failed");
> > > }
> > > }
> > > ===============================================================
> > > $ gcc -Wall foo.c
> > > $ ./a.out
> > >
> > > Expected output:
> > > c = 1: OK, 1 bytes
> > > c = 2: OK, 1 bytes
> > > c = 3: OK, 1 bytes
> > > c = 4: OK, 1 bytes
> > > c = 5: OK, 1 bytes
> > > c = 6: OK, 1 bytes
> > > c = 7: OK, 1 bytes
> > > c = 8: OK, 1 bytes
> > > c = 9: OK, 1 bytes
> > > c = 10: OK, 1 bytes
> > > c = 11: OK, 1 bytes
> > > c = 12: OK, 1 bytes
> > > c = 13: OK, 1 bytes
> > > c = 14: OK, 1 bytes
> > > c = 15: OK, 1 bytes
> > > c = 16: OK, 1 bytes
> > > c = 17: OK, 1 bytes
> > > c = 18: OK, 1 bytes
> > > c = 19: OK, 1 bytes
> > > c = 20: OK, 1 bytes
> > > c = 21: OK, 1 bytes
> > > c = 22: OK, 1 bytes
> > > c = 23: OK, 1 bytes
> > > c = 24: OK, 1 bytes
> > > c = 25: OK, 1 bytes
> > > c = 26: OK, 1 bytes
> > > c = 27: OK, 1 bytes
> > > c = 28: OK, 1 bytes
> > > c = 29: OK, 1 bytes
> > > c = 30: OK, 1 bytes
> > > c = 31: OK, 1 bytes
> > > c = 32: OK, 1 bytes
> > > c = 33: OK, 1 bytes
> > > c = 34: OK, 1 bytes
> > > c = 35: OK, 1 bytes
> > > c = 36: OK, 1 bytes
> > > c = 37: OK, 1 bytes
> > > c = 38: OK, 1 bytes
> > > c = 39: OK, 1 bytes
> > > c = 40: OK, 1 bytes
> > > c = 41: OK, 1 bytes
> > > c = 42: OK, 1 bytes
> > > c = 43: OK, 1 bytes
> > > c = 44: OK, 1 bytes
> > > c = 45: OK, 1 bytes
> > > c = 46: OK, 1 bytes
> > > c = 47: OK, 1 bytes
> > > c = 48: OK, 1 bytes
> > > c = 49: OK, 1 bytes
> > > c = 50: OK, 1 bytes
> > > c = 51: OK, 1 bytes
> > > c = 52: OK, 1 bytes
> > > c = 53: OK, 1 bytes
> > > c = 54: OK, 1 bytes
> > > c = 55: OK, 1 bytes
> > > c = 56: OK, 1 bytes
> > > c = 57: OK, 1 bytes
> > > c = 58: OK, 1 bytes
> > > c = 59: OK, 1 bytes
> > > c = 60: OK, 1 bytes
> > > c = 61: OK, 1 bytes
> > > c = 62: OK, 1 bytes
> > > c = 63: OK, 1 bytes
> > > c = 64: OK, 1 bytes
> > > c = 65: OK, 1 bytes
> > > c = 66: OK, 1 bytes
> > > c = 67: OK, 1 bytes
> > > c = 68: OK, 1 bytes
> > > c = 69: OK, 1 bytes
> > > c = 70: OK, 1 bytes
> > > c = 71: OK, 1 bytes
> > > c = 72: OK, 1 bytes
> > > c = 73: OK, 1 bytes
> > > c = 74: OK, 1 bytes
> > > c = 75: OK, 1 bytes
> > > c = 76: OK, 1 bytes
> > > c = 77: OK, 1 bytes
> > > c = 78: OK, 1 bytes
> > > c = 79: OK, 1 bytes
> > > c = 80: OK, 1 bytes
> > > c = 81: OK, 1 bytes
> > > c = 82: OK, 1 bytes
> > > c = 83: OK, 1 bytes
> > > c = 84: OK, 1 bytes
> > > c = 85: OK, 1 bytes
> > > c = 86: OK, 1 bytes
> > > c = 87: OK, 1 bytes
> > > c = 88: OK, 1 bytes
> > > c = 89: OK, 1 bytes
> > > c = 90: OK, 1 bytes
> > > c = 91: OK, 1 bytes
> > > c = 92: OK, 1 bytes
> > > c = 93: OK, 1 bytes
> > > c = 94: OK, 1 bytes
> > > c = 95: OK, 1 bytes
> > > c = 96: OK, 1 bytes
> > > c = 97: OK, 1 bytes
> > > c = 98: OK, 1 bytes
> > > c = 99: OK, 1 bytes
> > > c = 100: OK, 1 bytes
> > > c = 101: OK, 1 bytes
> > > c = 102: OK, 1 bytes
> > > c = 103: OK, 1 bytes
> > > c = 104: OK, 1 bytes
> > > c = 105: OK, 1 bytes
> > > c = 106: OK, 1 bytes
> > > c = 107: OK, 1 bytes
> > > c = 108: OK, 1 bytes
> > > c = 109: OK, 1 bytes
> > > c = 110: OK, 1 bytes
> > > c = 111: OK, 1 bytes
> > > c = 112: OK, 1 bytes
> > > c = 113: OK, 1 bytes
> > > c = 114: OK, 1 bytes
> > > c = 115: OK, 1 bytes
> > > c = 116: OK, 1 bytes
> > > c = 117: OK, 1 bytes
> > > c = 118: OK, 1 bytes
> > > c = 119: OK, 1 bytes
> > > c = 120: OK, 1 bytes
> > > c = 121: OK, 1 bytes
> > > c = 122: OK, 1 bytes
> > > c = 123: OK, 1 bytes
> > > c = 124: OK, 1 bytes
> > > c = 125: OK, 1 bytes
> > > c = 126: OK, 1 bytes
> > > c = 127: OK, 1 bytes
> > > c = 128: OK, 1 bytes
> > > c = 129: OK, 1 bytes
> > > c = 130: OK, 1 bytes
> > > c = 131: OK, 1 bytes
> > > c = 132: OK, 1 bytes
> > > c = 133: OK, 1 bytes
> > > c = 134: OK, 1 bytes
> > > c = 135: OK, 1 bytes
> > > c = 136: OK, 1 bytes
> > > c = 137: OK, 1 bytes
> > > c = 138: OK, 1 bytes
> > > c = 139: OK, 1 bytes
> > > c = 140: OK, 1 bytes
> > > c = 141: OK, 1 bytes
> > > c = 142: OK, 1 bytes
> > > c = 143: OK, 1 bytes
> > > c = 144: OK, 1 bytes
> > > c = 145: OK, 1 bytes
> > > c = 146: OK, 1 bytes
> > > c = 147: OK, 1 bytes
> > > c = 148: OK, 1 bytes
> > > c = 149: OK, 1 bytes
> > > c = 150: OK, 1 bytes
> > > c = 151: OK, 1 bytes
> > > c = 152: OK, 1 bytes
> > > c = 153: OK, 1 bytes
> > > c = 154: OK, 1 bytes
> > > c = 155: OK, 1 bytes
> > > c = 156: OK, 1 bytes
> > > c = 157: OK, 1 bytes
> > > c = 158: OK, 1 bytes
> > > c = 159: OK, 1 bytes
> > > c = 160: OK, 1 bytes
> > > c = 161: OK, 1 bytes
> > > c = 162: OK, 1 bytes
> > > c = 163: OK, 1 bytes
> > > c = 164: OK, 1 bytes
> > > c = 165: OK, 1 bytes
> > > c = 166: OK, 1 bytes
> > > c = 167: OK, 1 bytes
> > > c = 168: OK, 1 bytes
> > > c = 169: OK, 1 bytes
> > > c = 170: OK, 1 bytes
> > > c = 171: OK, 1 bytes
> > > c = 172: OK, 1 bytes
> > > c = 173: OK, 1 bytes
> > > c = 174: OK, 1 bytes
> > > c = 175: OK, 1 bytes
> > > c = 176: OK, 1 bytes
> > > c = 177: OK, 1 bytes
> > > c = 178: OK, 1 bytes
> > > c = 179: OK, 1 bytes
> > > c = 180: OK, 1 bytes
> > > c = 181: OK, 1 bytes
> > > c = 182: OK, 1 bytes
> > > c = 183: OK, 1 bytes
> > > c = 184: OK, 1 bytes
> > > c = 185: OK, 1 bytes
> > > c = 186: OK, 1 bytes
> > > c = 187: OK, 1 bytes
> > > c = 188: OK, 1 bytes
> > > c = 189: OK, 1 bytes
> > > c = 190: OK, 1 bytes
> > > c = 191: OK, 1 bytes
> > > c = 192: OK, 1 bytes
> > > c = 193: OK, 1 bytes
> > > c = 194: OK, 1 bytes
> > > c = 195: OK, 1 bytes
> > > c = 196: OK, 1 bytes
> > > c = 197: OK, 1 bytes
> > > c = 198: OK, 1 bytes
> > > c = 199: OK, 1 bytes
> > > c = 200: OK, 1 bytes
> > > c = 201: OK, 1 bytes
> > > c = 202: OK, 1 bytes
> > > c = 203: OK, 1 bytes
> > > c = 204: OK, 1 bytes
> > > c = 205: OK, 1 bytes
> > > c = 206: OK, 1 bytes
> > > c = 207: OK, 1 bytes
> > > c = 208: OK, 1 bytes
> > > c = 209: OK, 1 bytes
> > > c = 210: OK, 1 bytes
> > > c = 211: OK, 1 bytes
> > > c = 212: OK, 1 bytes
> > > c = 213: OK, 1 bytes
> > > c = 214: OK, 1 bytes
> > > c = 215: OK, 1 bytes
> > > c = 216: OK, 1 bytes
> > > c = 217: OK, 1 bytes
> > > c = 218: OK, 1 bytes
> > > c = 219: OK, 1 bytes
> > > c = 220: OK, 1 bytes
> > > c = 221: OK, 1 bytes
> > > c = 222: OK, 1 bytes
> > > c = 223: OK, 1 bytes
> > > c = 224: OK, 1 bytes
> > > c = 225: OK, 1 bytes
> > > c = 226: OK, 1 bytes
> > > c = 227: OK, 1 bytes
> > > c = 228: OK, 1 bytes
> > > c = 229: OK, 1 bytes
> > > c = 230: OK, 1 bytes
> > > c = 231: OK, 1 bytes
> > > c = 232: OK, 1 bytes
> > > c = 233: OK, 1 bytes
> > > c = 234: OK, 1 bytes
> > > c = 235: OK, 1 bytes
> > > c = 236: OK, 1 bytes
> > > c = 237: OK, 1 bytes
> > > c = 238: OK, 1 bytes
> > > c = 239: OK, 1 bytes
> > > c = 240: OK, 1 bytes
> > > c = 241: OK, 1 bytes
> > > c = 242: OK, 1 bytes
> > > c = 243: OK, 1 bytes
> > > c = 244: OK, 1 bytes
> > > c = 245: OK, 1 bytes
> > > c = 246: OK, 1 bytes
> > > c = 247: OK, 1 bytes
> > > c = 248: OK, 1 bytes
> > > c = 249: OK, 1 bytes
> > > c = 250: OK, 1 bytes
> > > c = 251: OK, 1 bytes
> > > c = 252: OK, 1 bytes
> > > c = 253: OK, 1 bytes
> > > c = 254: OK, 1 bytes
> > > c = 255: OK, 1 bytes
> > >
> > > Actual output:
> > > c = 1: OK, 1 bytes
> > > c = 2: OK, 1 bytes
> > > c = 3: OK, 1 bytes
> > > c = 4: OK, 1 bytes
> > > c = 5: OK, 1 bytes
> > > c = 6: OK, 1 bytes
> > > c = 7: OK, 1 bytes
> > > c = 8: OK, 1 bytes
> > > c = 9: OK, 1 bytes
> > > c = 10: OK, 1 bytes
> > > c = 11: OK, 1 bytes
> > > c = 12: OK, 1 bytes
> > > c = 13: OK, 1 bytes
> > > c = 14: OK, 1 bytes
> > > c = 15: OK, 1 bytes
> > > c = 16: OK, 1 bytes
> > > c = 17: OK, 1 bytes
> > > c = 18: OK, 1 bytes
> > > c = 19: OK, 1 bytes
> > > c = 20: OK, 1 bytes
> > > c = 21: OK, 1 bytes
> > > c = 22: OK, 1 bytes
> > > c = 23: OK, 1 bytes
> > > c = 24: OK, 1 bytes
> > > c = 25: OK, 1 bytes
> > > c = 26: OK, 1 bytes
> > > c = 27: OK, 1 bytes
> > > c = 28: OK, 1 bytes
> > > c = 29: OK, 1 bytes
> > > c = 30: OK, 1 bytes
> > > c = 31: OK, 1 bytes
> > > c = 32: OK, 1 bytes
> > > c = 33: OK, 1 bytes
> > > c = 34: OK, 1 bytes
> > > c = 35: OK, 1 bytes
> > > c = 36: OK, 1 bytes
> > > c = 37: OK, 1 bytes
> > > c = 38: OK, 1 bytes
> > > c = 39: OK, 1 bytes
> > > c = 40: OK, 1 bytes
> > > c = 41: OK, 1 bytes
> > > c = 42: OK, 1 bytes
> > > c = 43: OK, 1 bytes
> > > c = 44: OK, 1 bytes
> > > c = 45: OK, 1 bytes
> > > c = 46: OK, 1 bytes
> > > c = 47: OK, 1 bytes
> > > c = 48: OK, 1 bytes
> > > c = 49: OK, 1 bytes
> > > c = 50: OK, 1 bytes
> > > c = 51: OK, 1 bytes
> > > c = 52: OK, 1 bytes
> > > c = 53: OK, 1 bytes
> > > c = 54: OK, 1 bytes
> > > c = 55: OK, 1 bytes
> > > c = 56: OK, 1 bytes
> > > c = 57: OK, 1 bytes
> > > c = 58: OK, 1 bytes
> > > c = 59: OK, 1 bytes
> > > c = 60: OK, 1 bytes
> > > c = 61: OK, 1 bytes
> > > c = 62: OK, 1 bytes
> > > c = 63: OK, 1 bytes
> > > c = 64: OK, 1 bytes
> > > c = 65: OK, 1 bytes
> > > c = 66: OK, 1 bytes
> > > c = 67: OK, 1 bytes
> > > c = 68: OK, 1 bytes
> > > c = 69: OK, 1 bytes
> > > c = 70: OK, 1 bytes
> > > c = 71: OK, 1 bytes
> > > c = 72: OK, 1 bytes
> > > c = 73: OK, 1 bytes
> > > c = 74: OK, 1 bytes
> > > c = 75: OK, 1 bytes
> > > c = 76: OK, 1 bytes
> > > c = 77: OK, 1 bytes
> > > c = 78: OK, 1 bytes
> > > c = 79: OK, 1 bytes
> > > c = 80: OK, 1 bytes
> > > c = 81: OK, 1 bytes
> > > c = 82: OK, 1 bytes
> > > c = 83: OK, 1 bytes
> > > c = 84: OK, 1 bytes
> > > c = 85: OK, 1 bytes
> > > c = 86: OK, 1 bytes
> > > c = 87: OK, 1 bytes
> > > c = 88: OK, 1 bytes
> > > c = 89: OK, 1 bytes
> > > c = 90: OK, 1 bytes
> > > c = 91: OK, 1 bytes
> > > c = 92: OK, 1 bytes
> > > c = 93: OK, 1 bytes
> > > c = 94: OK, 1 bytes
> > > c = 95: OK, 1 bytes
> > > c = 96: OK, 1 bytes
> > > c = 97: OK, 1 bytes
> > > c = 98: OK, 1 bytes
> > > c = 99: OK, 1 bytes
> > > c = 100: OK, 1 bytes
> > > c = 101: OK, 1 bytes
> > > c = 102: OK, 1 bytes
> > > c = 103: OK, 1 bytes
> > > c = 104: OK, 1 bytes
> > > c = 105: OK, 1 bytes
> > > c = 106: OK, 1 bytes
> > > c = 107: OK, 1 bytes
> > > c = 108: OK, 1 bytes
> > > c = 109: OK, 1 bytes
> > > c = 110: OK, 1 bytes
> > > c = 111: OK, 1 bytes
> > > c = 112: OK, 1 bytes
> > > c = 113: OK, 1 bytes
> > > c = 114: OK, 1 bytes
> > > c = 115: OK, 1 bytes
> > > c = 116: OK, 1 bytes
> > > c = 117: OK, 1 bytes
> > > c = 118: OK, 1 bytes
> > > c = 119: OK, 1 bytes
> > > c = 120: OK, 1 bytes
> > > c = 121: OK, 1 bytes
> > > c = 122: OK, 1 bytes
> > > c = 123: OK, 1 bytes
> > > c = 124: OK, 1 bytes
> > > c = 125: OK, 1 bytes
> > > c = 126: OK, 1 bytes
> > > c = 127: OK, 1 bytes
> > > c = 128: OK, 1 bytes
> > > c = 129: OK, 1 bytes
> > > c = 130: OK, 1 bytes
> > > c = 131: OK, 1 bytes
> > > c = 132: OK, 1 bytes
> > > c = 133: OK, 1 bytes
> > > c = 134: OK, 1 bytes
> > > c = 135: OK, 1 bytes
> > > c = 136: OK, 1 bytes
> > > c = 137: OK, 1 bytes
> > > c = 138: OK, 1 bytes
> > > c = 139: OK, 1 bytes
> > > c = 140: OK, 1 bytes
> > > c = 141: OK, 1 bytes
> > > c = 142: OK, 1 bytes
> > > c = 143: OK, 1 bytes
> > > c = 144: OK, 1 bytes
> > > c = 145: OK, 1 bytes
> > > c = 146: OK, 1 bytes
> > > c = 147: OK, 1 bytes
> > > c = 148: OK, 1 bytes
> > > c = 149: OK, 1 bytes
> > > c = 150: OK, 1 bytes
> > > c = 151: OK, 1 bytes
> > > c = 152: OK, 1 bytes
> > > c = 153: OK, 1 bytes
> > > c = 154: OK, 1 bytes
> > > c = 155: OK, 1 bytes
> > > c = 156: OK, 1 bytes
> > > c = 157: OK, 1 bytes
> > > c = 158: OK, 1 bytes
> > > c = 159: OK, 1 bytes
> > > c = 160: OK, 1 bytes
> > > c = 161: OK, 1 bytes
> > > c = 162: OK, 1 bytes
> > > c = 163: OK, 1 bytes
> > > c = 164: OK, 1 bytes
> > > c = 165: OK, 1 bytes
> > > c = 166: OK, 1 bytes
> > > c = 167: OK, 1 bytes
> > > c = 168: OK, 1 bytes
> > > c = 169: OK, 1 bytes
> > > c = 170: OK, 1 bytes
> > > c = 171: OK, 1 bytes
> > > c = 172: OK, 1 bytes
> > > c = 173: OK, 1 bytes
> > > c = 174: OK, 1 bytes
> > > c = 175: OK, 1 bytes
> > > c = 176: OK, 1 bytes
> > > c = 177: OK, 1 bytes
> > > c = 178: OK, 1 bytes
> > > c = 179: OK, 1 bytes
> > > c = 180: OK, 1 bytes
> > > c = 181: OK, 1 bytes
> > > c = 182: OK, 1 bytes
> > > c = 183: OK, 1 bytes
> > > c = 184: OK, 1 bytes
> > > c = 185: OK, 1 bytes
> > > c = 186: OK, 1 bytes
> > > c = 187: OK, 1 bytes
> > > c = 188: OK, 1 bytes
> > > c = 189: OK, 1 bytes
> > > c = 190: OK, 1 bytes
> > > c = 191: OK, 1 bytes
> > > c = 192: OK, 1 bytes
> > > c = 193: OK, 1 bytes
> > > c = 194: OK, 1 bytes
> > > c = 195: OK, 1 bytes
> > > c = 196: OK, 1 bytes
> > > c = 197: OK, 1 bytes
> > > c = 198: OK, 1 bytes
> > > c = 199: OK, 1 bytes
> > > c = 200: OK, 1 bytes
> > > c = 201: OK, 1 bytes
> > > c = 202: OK, 1 bytes
> > > c = 203: OK, 1 bytes
> > > c = 204: OK, 1 bytes
> > > c = 205: OK, 1 bytes
> > > c = 206: OK, 1 bytes
> > > c = 207: OK, 1 bytes
> > > c = 208: OK, 1 bytes
> > > c = 209: OK, 1 bytes
> > > c = 210: OK, 1 bytes
> > > c = 211: OK, 1 bytes
> > > c = 212: OK, 1 bytes
> > > c = 213: OK, 1 bytes
> > > c = 214: OK, 1 bytes
> > > c = 215: OK, 1 bytes
> > > c = 216: OK, 1 bytes
> > > c = 217: OK, 1 bytes
> > > c = 218: OK, 1 bytes
> > > c = 219: OK, 1 bytes
> > > c = 220: OK, 1 bytes
> > > c = 221: OK, 1 bytes
> > > c = 222: OK, 1 bytes
> > > c = 223: OK, 1 bytes
> > > c = 224: OK, 1 bytes
> > > c = 225: OK, 1 bytes
> > > c = 226: OK, 1 bytes
> > > c = 227: OK, 1 bytes
> > > c = 228: OK, 1 bytes
> > > c = 229: OK, 1 bytes
> > > c = 230: OK, 1 bytes
> > > c = 231: OK, 1 bytes
> > > c = 232: OK, 1 bytes
> > > c = 233: OK, 1 bytes
> > > c = 234: OK, 1 bytes
> > > c = 235: OK, 1 bytes
> > > c = 236: OK, 1 bytes
> > > c = 237: OK, 1 bytes
> > > c = 238: OK, 1 bytes
> > > c = 239: OK, 1 bytes
> > > c = 240: OK, 1 bytes
> > > c = 241: OK, 1 bytes
> > > c = 242: OK, 1 bytes
> > > c = 243: OK, 1 bytes
> > > c = 244: OK, 1 bytes
> > > c = 245: OK, 1 bytes
> > > c = 246: OK, 1 bytes
> > > c = 247: OK, 1 bytes
> > > c = 248: OK, 1 bytes
> > > c = 249: OK, 1 bytes
> > > c = 250: OK, 1 bytes
> > > c = 251: OK, 1 bytes
> > > c = 252: OK, 1 bytes
> > > c = 253: OK, 1 bytes
> > > c = 254: OK, 1 bytes
> > > c = 255: swprintf failed: Illegal byte sequence
> > >
> > > This is a bug, because POSIX says that in the C / POSIX locale, "all byte
> > > values are valid characters" [1].
> >
> > Yes, this is a bug and seems to be an instance of mishandling of
> > signed conversions. Attached should correct it.
> >
> > Rich
>
> > diff --git a/src/stdio/vfwprintf.c b/src/stdio/vfwprintf.c
> > index 53697701..a653e233 100644
> > --- a/src/stdio/vfwprintf.c
> > +++ b/src/stdio/vfwprintf.c
> > @@ -271,7 +271,7 @@ static int wprintf_core(FILE *f, const wchar_t *fmt, va_list *ap, union arg *nl_
> > case 'C':
> > if (w<1) w=1;
> > pad(f, w-1, fl);
> > - out(f, &(wchar_t){t=='C' ? arg.i : btowc(arg.i)}, 1);
> > + out(f, &(wchar_t){t=='C' ? arg.i : btowc(arg.i & 0xff)}, 1);
> > pad(f, w-1, fl^LEFT_ADJ);
> > l = w;
> > continue;
>
> Hmm -- while this works, formally, %c takes an argument of type int
> not char, so I think we should probably actually change the state
> machine for both narrow and wide printf to terminate with state INT
> rather than CHAR for 'c'. And likewise, %lc/%C takes wint_t, which has
> type unsigned, so although it doesn't matter the state machine should
> terminate with state UINT rather than INT (wint_t is unsigned).
And the plot thickens...
For narrow printf, it's required to work even if you pass -1:
c
The int argument shall be converted to an unsigned char, and the
resulting byte shall be written.
This already works regardless of what we do just by assignment into a
char array.
However, for wide printf:
c
If no l (ell) qualifier is present, the int argument shall be
converted to a wide character as if by calling the btowc()
function and the resulting wide character shall be written.
There's no specification of what happens if btowc fails here, but
passing EOF to btowc is required to fail and return WEOF. It can also
fail depending on locale.
Rich
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [musl] swprintf cannot handle the character 0xff
2023-06-12 21:13 ` Rich Felker
@ 2023-06-12 23:09 ` Bruno Haible
2023-06-12 23:54 ` Rich Felker
0 siblings, 1 reply; 7+ messages in thread
From: Bruno Haible @ 2023-06-12 23:09 UTC (permalink / raw)
To: Rich Felker; +Cc: musl
Rich Felker wrote:
> However, for wide printf:
>
> c
> If no l (ell) qualifier is present, the int argument shall be
> converted to a wide character as if by calling the btowc()
> function and the resulting wide character shall be written.
>
> There's no specification of what happens if btowc fails here, but
> passing EOF to btowc is required to fail and return WEOF.
Possibly. But in the test program that I provided, I pass 255, not
-1 (= EOF).
It's well-known that the preferred way to convert a 'char' to 'int'
is not by direct assigment/cast, but by casting to 'unsigned char'.
That's well-known from [f]getc(), the <ctype.h> functions, etc.
You don't need to particularly care about programmers who pass
'\xff' to a function that expects an 'int'.
Bruno
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [musl] swprintf cannot handle the character 0xff
2023-06-12 23:09 ` Bruno Haible
@ 2023-06-12 23:54 ` Rich Felker
2023-06-13 0:23 ` Bruno Haible
0 siblings, 1 reply; 7+ messages in thread
From: Rich Felker @ 2023-06-12 23:54 UTC (permalink / raw)
To: Bruno Haible; +Cc: musl
On Tue, Jun 13, 2023 at 01:09:26AM +0200, Bruno Haible wrote:
> Rich Felker wrote:
> > However, for wide printf:
> >
> > c
> > If no l (ell) qualifier is present, the int argument shall be
> > converted to a wide character as if by calling the btowc()
> > function and the resulting wide character shall be written.
> >
> > There's no specification of what happens if btowc fails here, but
> > passing EOF to btowc is required to fail and return WEOF.
>
> Possibly. But in the test program that I provided, I pass 255, not
> -1 (= EOF).
Right. I'm not questioning that your bug report is correct, just my
initial proposal for fixing it. Since wide printf is supposed to
perform the conversion as if by btowc, it should presumably handle -1
(as opposed to 255) as an error path.
> It's well-known that the preferred way to convert a 'char' to 'int'
> is not by direct assigment/cast, but by casting to 'unsigned char'.
> That's well-known from [f]getc(), the <ctype.h> functions, etc.
> You don't need to particularly care about programmers who pass
> '\xff' to a function that expects an 'int'.
On targets where plain char is signed, '\xff' has value -1, meaning it
would work for %c with narrow printf but not with wide printf. I
wonder if this should actually be a defect and if wide printf should
be specified as converting the value, converted to (unsigned char), as
if by btowc, rather than the raw value.
Rich
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [musl] swprintf cannot handle the character 0xff
2023-06-12 23:54 ` Rich Felker
@ 2023-06-13 0:23 ` Bruno Haible
0 siblings, 0 replies; 7+ messages in thread
From: Bruno Haible @ 2023-06-13 0:23 UTC (permalink / raw)
To: Rich Felker; +Cc: musl
Rich Felker wrote:
> I wonder if this should actually be a defect and if wide printf should
> be specified as converting the value, converted to (unsigned char), as
> if by btowc, rather than the raw value.
I agree. If ISO C and POSIX had specified or would specify %c in wide printf
like this, it would eliminate a (small) pitfall for programmers.
Bruno
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2023-06-13 0:23 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-06-12 12:30 [musl] swprintf cannot handle the character 0xff Bruno Haible
2023-06-12 20:22 ` Rich Felker
2023-06-12 21:01 ` Rich Felker
2023-06-12 21:13 ` Rich Felker
2023-06-12 23:09 ` Bruno Haible
2023-06-12 23:54 ` Rich Felker
2023-06-13 0:23 ` Bruno Haible
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