[FFmpeg-devel] [PATCH] avutil/timestamp: avoid possible FPE when 0 is passed to av_ts_make_time_string2()

[Rémi Denis-Courmont]

Le 17 juin 2024 22:33:01 GMT+02:00, Marton Balint <cus at passwd.hu> a écrit :
>Signed-off-by: Marton Balint <cus at passwd.hu>
>---
> libavutil/timestamp.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/libavutil/timestamp.c b/libavutil/timestamp.c
>index 2a3e3012a4..6c231a517d 100644
>--- a/libavutil/timestamp.c
>+++ b/libavutil/timestamp.c
>@@ -24,7 +24,7 @@ char *av_ts_make_time_string2(char *buf, int64_t ts, AVRational tb)
>         snprintf(buf, AV_TS_MAX_STRING_SIZE, "NOPTS");
>     } else {
>         double val = av_q2d(tb) * ts;
>-        double log = floor(log10(fabs(val)));
>+        double log = (fpclassify(val) == FP_ZERO ? -INFINITY : floor(log10(fabs(val))));
>         int precision = (isfinite(log) && log < 0) ? -log + 5 : 6;

Can the log be infinite anymore?

>         int last = snprintf(buf, AV_TS_MAX_STRING_SIZE, "%.*f", precision, val);
>         last = FFMIN(last, AV_TS_MAX_STRING_SIZE - 1) - 1;