demux_libarchive: open flat compressed files

Things like .gz etc., which have no real file header. A mixed bag,
because it e.g. tends to misdetect mp3 files as compressed files or
something (of course it has no mp3 support - I don't know as what it
detects them). But requested by someone (or maybe not, I'm not sure
how to interpret that).

demux/demux_libarchive.c

@@ -32,7 +32,10 @@ static int cmp_filename(const void *a, const void *b)
 
 static int open_file(struct demuxer *demuxer, enum demux_check check)
 {
-    struct mp_archive *mpa = mp_archive_new(demuxer->log, demuxer->stream);
+    int flags = 0;
+    if (check <= DEMUX_CHECK_REQUEST)
+        flags |= MP_ARCHIVE_FLAG_UNSAFE;
+    struct mp_archive *mpa = mp_archive_new(demuxer->log, demuxer->stream, flags);
     if (!mpa)
         return -1;
 

stream/stream_libarchive.c

@@ -71,7 +71,8 @@ void mp_archive_free(struct mp_archive *mpa)
     talloc_free(mpa);
 }
 
-struct mp_archive *mp_archive_new(struct mp_log *log, struct stream *src)
+struct mp_archive *mp_archive_new(struct mp_log *log, struct stream *src,
+                                  int flags)
 {
     struct mp_archive *mpa = talloc_zero(NULL, struct mp_archive);
     mpa->src = src;
@@ -81,6 +82,8 @@ struct mp_archive *mp_archive_new(struct mp_log *log, struct stream *src)
         goto err;
     archive_read_support_format_all(mpa->arch);
     archive_read_support_filter_all(mpa->arch);
+    if (flags & MP_ARCHIVE_FLAG_UNSAFE)
+        archive_read_support_format_raw(mpa->arch);
     archive_read_set_callback_data(mpa->arch, mpa);
     archive_read_set_read_callback(mpa->arch, read_cb);
     archive_read_set_skip_callback(mpa->arch, skip_cb);
@@ -106,7 +109,7 @@ static int reopen_archive(stream_t *s)
 {
     struct priv *p = s->priv;
     mp_archive_free(p->mpa);
-    p->mpa = mp_archive_new(s->log, p->src);
+    p->mpa = mp_archive_new(s->log, p->src, MP_ARCHIVE_FLAG_UNSAFE);
     if (!p->mpa)
         return STREAM_ERROR;
 

stream/stream_libarchive.h

@@ -7,4 +7,7 @@ struct mp_archive {
 };
 
 void mp_archive_free(struct mp_archive *mpa);
-struct mp_archive *mp_archive_new(struct mp_log *log, struct stream *src);
+
+#define MP_ARCHIVE_FLAG_UNSAFE 1
+struct mp_archive *mp_archive_new(struct mp_log *log, struct stream *src,
+                                  int flags);