charset_conv: make it possible to return an allocated string as guess

uchardet is written in C++, and thus doesn't appreciate the value of
using static strings, and internally stores the guessed charset as
allocated std::string. Add a minimal hack to deal with this. (I don't
appreciate that the code is potentially harder to understand by
returning either a static or allocated string, but I do appreciate for
not having to litter the existing code with strdups.)

1 files changed, 4 insertions, 4 deletions

diff --git a/sub/dec_sub.c b/sub/dec_sub.c
index 1800cf34d9..20fa9eff83 100644
--- a/sub/dec_sub.c
+++ b/sub/dec_sub.c
@@ -303,8 +303,8 @@ void sub_decode(struct dec_sub *sub, struct demux_packet *packet)
     pthread_mutex_unlock(&sub->lock);
 }
 
-static const char *guess_sub_cp(struct mp_log *log, struct packet_list *subs,
-                                const char *usercp)
+static const char *guess_sub_cp(struct mp_log *log, void *talloc_ctx,
+                                struct packet_list *subs, const char *usercp)
 {
     if (!mp_charset_requires_guess(usercp))
         return usercp;
@@ -330,7 +330,7 @@ static const char *guess_sub_cp(struct mp_log *log, struct packet_list *subs,
         memcpy(text.start + text.len + pkt->len, sep, sep_len);
         text.len += pkt->len + sep_len;
     }
-    const char *guess = mp_charset_guess(log, text, usercp, 0);
+    const char *guess = mp_charset_guess(talloc_ctx, log, text, usercp, 0);
     talloc_free(text.start);
     return guess;
 }
@@ -455,7 +455,7 @@ bool sub_read_all_packets(struct dec_sub *sub, struct sh_stream *sh)
     }
 
     if (opts->sub_cp && !sh->sub->is_utf8)
-        sub->charset = guess_sub_cp(sub->log, subs, opts->sub_cp);
+        sub->charset = guess_sub_cp(sub->log, sub, subs, opts->sub_cp);
 
     if (sub->charset && sub->charset[0] && !mp_charset_is_utf8(sub->charset))
         MP_INFO(sub, "Using subtitle charset: %s\n", sub->charset);