Mercurial > hg > octave-lojdl > gnulib-hg
changeset 9361:40389da21b02
Don't use %n on glibc >= 2.3 systems.
| author | Bruno Haible <bruno@clisp.org> |
|---|---|
| date | Fri, 19 Oct 2007 01:50:42 +0200 |
| parents | 7b62d3737179 |
| children | 8f61b607ab56 |
| files | ChangeLog lib/vasnprintf.c |
| diffstat | 2 files changed, 17 insertions(+), 0 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2007-10-18 Bruno Haible <bruno@clisp.org> + + * m4/vasnprintf.m4 (VASNPRINTF): Don't use %n on glibc >= 2.3 systems. + Reported by Jim Meyering. + 2007-10-18 Eric Blake <ebb9@byu.net> * modules/filenamecat-tests (Makefile.am): Link against -lintl.
--- a/lib/vasnprintf.c +++ b/lib/vasnprintf.c @@ -3385,9 +3385,21 @@ #endif *fbp = dp->conversion; #if USE_SNPRINTF +# if !(__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3)) fbp[1] = '%'; fbp[2] = 'n'; fbp[3] = '\0'; +# else + /* On glibc2 systems from glibc >= 2.3 - probably also older + ones - we know that snprintf's returns value conforms to + ISO C 99: the gl_SNPRINTF_DIRECTIVE_N test passes. + Therefore we can avoid using %n in this situation. + On glibc2 systems from 2004-10-18 or newer, the use of %n + in format strings in writable memory may crash the program + (if compiled with _FORTIFY_SOURCE=2), so we should avoid it + in this situation. */ + fbp[1] = '\0'; +# endif #else fbp[1] = '\0'; #endif