stdio-common: Also reject exp char w/o significand in i18n scanf [BZ #13988]

Fix the handling of real 'scanf' input such as "+.e" as per BZ #13988
for the i18n case as well, complementing commit 6ecec3b616 ("Don't
accept exp char without preceding digits in scanf float parsing"), where
the 'e' character is incorrectly consumed from input.  Add a test case
matching stdio-common/bug26.c, with bits from localedata/tst-sscanf.c.

Reviewed-by: Joseph Myers <josmyers@redhat.com>
This commit is contained in:
Maciej W. Rozycki 2025-03-28 12:35:53 +00:00
parent 47076b3163
commit a26638424f
3 changed files with 63 additions and 3 deletions

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@ -236,6 +236,7 @@ tests = \
bug-iconv-trans \
bug-setlocale1 \
bug-usesetlocale \
tst-bz13988 \
tst-c-utf8-consistency \
tst-digits \
tst-iconv-emojis-trans \

53
localedata/tst-bz13988.c Normal file
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@ -0,0 +1,53 @@
/* Localized test for BZ #13988.
Copyright (C) 2025 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <locale.h>
#include <stdio.h>
#include <string.h>
#include <libc-diag.h>
#include <support/check.h>
#define PD "\xd9\xab"
static int
do_test (void)
{
if (setlocale (LC_ALL, "fa_IR.UTF-8") == NULL)
FAIL_EXIT1 ("setlocale (LC_ALL, \"fa_IR.UTF-8\")");
char s[] = "+" PD "e";
FILE *f = fmemopen (s, strlen (s), "r");
/* Avoid: "warning: 'I' flag used with '%f' gnu_scanf format [-Wformat=]";
cf. GCC PR c/119514. */
DIAG_PUSH_NEEDS_COMMENT;
DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wformat");
/* This should fail to parse a floating-point number, and leave 'e' in the
input. */
double d;
TEST_VERIFY_EXIT (fscanf (f, "%Ilf", &d) == 0);
TEST_VERIFY_EXIT (fgetc (f) == 'e');
DIAG_POP_NEEDS_COMMENT;
return 0;
}
#include <support/test-driver.c>

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@ -2409,7 +2409,7 @@ digits_extended_fail:
if (got_e && charbuf.current[-1] == exp_char
&& (c == L_('-') || c == L_('+')))
char_buffer_add (&charbuf, c);
else if (char_buffer_size (&charbuf) > got_sign && !got_e
else if (got_digit && !got_e
&& (CHAR_T) TOLOWER (c) == exp_char)
{
char_buffer_add (&charbuf, exp_char);
@ -2426,7 +2426,10 @@ digits_extended_fail:
if (c == wcdigits[n])
{
if (n < 10)
char_buffer_add (&charbuf, L_('0') + n);
{
char_buffer_add (&charbuf, L_('0') + n);
got_digit = 1;
}
else if (n == 11 && !got_dot)
{
char_buffer_add (&charbuf, decimal);
@ -2461,7 +2464,10 @@ digits_extended_fail:
width = avail;
if (n < 10)
char_buffer_add (&charbuf, L_('0') + n);
{
char_buffer_add (&charbuf, L_('0') + n);
got_digit = 1;
}
else if (n == 11 && !got_dot)
{
/* Add all the characters. */