[PATCH] ucrtbase: Always return the full string length in __stdio_common_vs[w]printf for a NULL buffer
If the target is a NULL buffer (with a zero length), we should always return the full size the format would have needed, even if UCRTBASE_PRINTF_STANDARD_SNPRINTF_BEHAVIOUR isn't specified. Signed-off-by: Martin Storsjo <martin(a)martin.st> --- I know the subject line should be shorter - feel free to change it to a shorter form. --- dlls/msvcrt/wcs.c | 4 ++++ dlls/ucrtbase/tests/printf.c | 11 +++++++++++ 2 files changed, 15 insertions(+) diff --git a/dlls/msvcrt/wcs.c b/dlls/msvcrt/wcs.c index 88f52e0..0c54800 100644 --- a/dlls/msvcrt/wcs.c +++ b/dlls/msvcrt/wcs.c @@ -764,6 +764,8 @@ int CDECL MSVCRT__stdio_common_vsprintf( unsigned __int64 options, char *str, MS &ctx, format, locale, options & UCRTBASE_PRINTF_MASK, arg_clbk_valist, NULL, &valist); puts_clbk_str_a(&ctx, 1, &nullbyte); + if(!str) + return ret; if(options & UCRTBASE_PRINTF_LEGACY_VSPRINTF_NULL_TERMINATION) return ret>len ? -1 : ret; if(ret>=len) { @@ -1282,6 +1284,8 @@ int CDECL MSVCRT__stdio_common_vswprintf( unsigned __int64 options, &ctx, format, locale, options & UCRTBASE_PRINTF_MASK, arg_clbk_valist, NULL, &valist); puts_clbk_str_w(&ctx, 1, &nullbyte); + if(!str) + return ret; if(options & UCRTBASE_PRINTF_LEGACY_VSPRINTF_NULL_TERMINATION) return ret>len ? -1 : ret; if(ret>=len) { diff --git a/dlls/ucrtbase/tests/printf.c b/dlls/ucrtbase/tests/printf.c index 77fb560..0e38003 100644 --- a/dlls/ucrtbase/tests/printf.c +++ b/dlls/ucrtbase/tests/printf.c @@ -215,6 +215,10 @@ static void test_snprintf (void) ok (vsprintf_wrapper (UCRTBASE_PRINTF_STANDARD_SNPRINTF_BEHAVIOUR, NULL, 0, "abcd") == 4, "Failure to snprintf to NULL\n"); + ok (vsprintf_wrapper (UCRTBASE_PRINTF_LEGACY_VSPRINTF_NULL_TERMINATION, NULL, 0, "abcd") == 4, + "Failure to snprintf to NULL\n"); + ok (vsprintf_wrapper (0, NULL, 0, "abcd") == 4, + "Failure to snprintf to NULL\n"); } static int WINAPIV vswprintf_wrapper(unsigned __int64 options, wchar_t *str, @@ -289,6 +293,13 @@ static void test_swprintf (void) ok (buffer[valid] == '\0', "\"%s\": Missing null termination (ret %d) - is %d\n", narrow_fmt, n, buffer[valid]); } + + ok (vswprintf_wrapper (UCRTBASE_PRINTF_STANDARD_SNPRINTF_BEHAVIOUR, NULL, 0, str_short) == 5, + "Failure to swprintf to NULL\n"); + ok (vswprintf_wrapper (UCRTBASE_PRINTF_LEGACY_VSPRINTF_NULL_TERMINATION, NULL, 0, str_short) == 5, + "Failure to swprintf to NULL\n"); + ok (vswprintf_wrapper (0, NULL, 0, str_short) == 5, + "Failure to swprintf to NULL\n"); } static int WINAPIV vfprintf_wrapper(FILE *file, -- 2.7.4
participants (2)
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Martin Storsjo -
Piotr Caban