[FFmpeg-cvslog] avfilter/avfilter: Honour the short options documentation

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Sat Sep 11 13:07:00 2021 +0200| [0c800c0b48f94edfa82e4bd4579ef3f27fdc49c2] | committer: Andreas Rheinhardt

avfilter/avfilter: Honour the short options documentation

The documentation for filter arguments states that short options must
precede long options (i.e. those of the form key=value). Yet if
process_options() encounters arguments not abiding by this, it simply
treats short options after a long option as if it were parsing short
options for the first time. In particular, it overwrites options already
set earlier, possibly via other short options. This is not how it is
intended (as a comment in the code indicates).

This commit modifies the code to reject further shorthand options
after a long option has been encountered. After all, avfilter_init_str()
errors out upon unrecognized options, so it is intended to be picky.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0c800c0b48f94edfa82e4bd4579ef3f27fdc49c2
---

 libavfilter/avfilter.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
index 508fe1b26b..21d6832deb 100644
--- a/libavfilter/avfilter.c
+++ b/libavfilter/avfilter.c
@@ -846,9 +846,7 @@ int ff_filter_opt_parse(void *logctx, const AVClass *priv_class,
         const char *shorthand = NULL;
         int additional_flags  = 0;
 
-        if (priv_class)
-            o = av_opt_next(&priv_class, o);
-        if (o) {
+        if (priv_class && (o = av_opt_next(&priv_class, o))) {
             if (o->type == AV_OPT_TYPE_CONST || o->offset == offset)
                 continue;
             offset = o->offset;
@@ -871,9 +869,7 @@ int ff_filter_opt_parse(void *logctx, const AVClass *priv_class,
         if (parsed_key) {
             key = parsed_key;
             additional_flags = AV_DICT_DONT_STRDUP_KEY;
-            /* discard all remaining shorthand */
-            if (priv_class)
-                while ((o = av_opt_next(&priv_class, o)));
+            priv_class = NULL; /* reject all remaining shorthand */
         } else {
             key = shorthand;
         }