@@ -309,6 +309,8 @@ static int set_string_binary(void *obj, const AVOption *o, const char *val, uint
static int set_string(void *obj, const AVOption *o, const char *val, uint8_t **dst)
{
av_freep(dst);
+ if (!val)
+ return 0;
*dst = av_strdup(val);
return *dst ? 0 : AVERROR(ENOMEM);
}
@@ -2032,9 +2034,11 @@ static int opt_copy_elem(void *logctx, enum AVOptionType type,
if (type == AV_OPT_TYPE_STRING) {
if (*dst8 != *src8)
av_freep(dst8);
- *dst8 = av_strdup(*src8);
- if (*src8 && !*dst8)
- return AVERROR(ENOMEM);
+ if (*src8) {
+ *dst8 = av_strdup(*src8);
+ if (!*dst8)
+ return AVERROR(ENOMEM);
+ }
} else if (type == AV_OPT_TYPE_BINARY) {
int len = *(const int *)(src8 + 1);
if (*dst8 != *src8)
It is not documented to be safe and in any case it is nonsense: Currently av_strdup(NULL) returns NULL and in order to distinguish this from a genuine allocation failure, opt_copy_elem() checked afterwards whether src was actually NULL. But then one can simply check in advance whether one should call av_strdup() at all. set_string() was even worse and returned ENOMEM in case the value to be duplicated is NULL; this only worked because av_opt_set_defaults2() does not check the return value at all (given that it can't propagate it). These two places account for 389114 of 390356 av_strdup(NULL) calls during one FATE run. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com> --- libavutil/opt.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)