diff options
| author | Bruno Haible <bruno@clisp.org> | 2019-01-23 01:17:07 +0100 |
|---|---|---|
| committer | Bruno Haible <bruno@clisp.org> | 2019-01-23 01:23:30 +0100 |
| commit | 6c0f109fb98501fc8d65ea2c83501b45a80b00ab (patch) | |
| tree | c275b20366ca12b18df8a1515294e3a96f4afeef /lib/vasnprintf.c | |
| parent | 5447f440ef927283e63d5a1290dab292f7af1aea (diff) | |
| download | gnulib-6c0f109fb98501fc8d65ea2c83501b45a80b00ab.tar.gz | |
vasnprintf: Don't use %n on Android.
Reported and fix suggested by Hugo Beauzée-Luyssen <hugo@beauzee.fr> in
<https://lists.gnu.org/archive/html/bug-gnulib/2018-12/msg00123.html>.
* lib/vasnprintf.c (VASNPRINTF): Don’t use %n on Android.
Diffstat (limited to 'lib/vasnprintf.c')
| -rw-r--r-- | lib/vasnprintf.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c index 465ecc3544..b14a95962b 100644 --- a/lib/vasnprintf.c +++ b/lib/vasnprintf.c @@ -4874,6 +4874,7 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, # if ! (((__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) \ && !defined __UCLIBC__) \ || (defined __APPLE__ && defined __MACH__) \ + || defined __ANDROID__ \ || (defined _WIN32 && ! defined __CYGWIN__)) fbp[1] = '%'; fbp[2] = 'n'; @@ -4895,6 +4896,14 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp, On Mac OS X 10.13 or newer, the use of %n in format strings in writable memory by default crashes the program, so we should avoid it in this situation. */ + /* On Android, we know that snprintf's return value conforms to + ISO C 99: the tests gl_SNPRINTF_RETVAL_C99 and + gl_SNPRINTF_TRUNCATION_C99 pass. + Therefore we can avoid using %n in this situation. + Starting on 2018-03-07, the use of %n in format strings + produces a fatal error (see + <https://android.googlesource.com/platform/bionic/+/41398d03b7e8e0dfb951660ae713e682e9fc0336>), + so we should avoid it. */ /* On native Windows systems (such as mingw), we can avoid using %n because: - Although the gl_SNPRINTF_TRUNCATION_C99 test fails, |