hlsenc: Fixing HLS_TEMP_FILE usage with HLS_SECOND_LEVEL_SEGMENT_...

Currently using HLS_TEMP together with HLS_SECOND_LEVEL_SEGMENT_DURATION
or HLS_SECOND_LEVEL_SEGMENT_SIZE gives error at end of each segment
writing and the final segment file names do not contain the desired
data. This patch fixes this bug by delaying the initilization of
original segment filename after actual temp file renaming will skip the
interfering.
Signed-off-by: NBela Bodecs <bodecsb@vivanet.hu>

libavformat/hlsenc.c

@@ -2168,13 +2168,9 @@ static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
     if (vs->packets_written && can_split && av_compare_ts(pkt->pts - vs->start_pts, st->time_base,
                                    end_pts, AV_TIME_BASE_Q) >= 0) {
         int64_t new_start_pos;
-        char *old_filename = av_strdup(vs->avf->url);
+        char *old_filename = NULL;
         int byterange_mode = (hls->flags & HLS_SINGLE_FILE) || (hls->max_seg_size > 0);
 
-        if (!old_filename) {
-            return AVERROR(ENOMEM);
-        }
-
         av_write_frame(vs->avf, NULL); /* Flush any buffered data */
 
         new_start_pos = avio_tell(vs->avf->pb);
@@ -2215,17 +2211,21 @@ static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
             if (ret < 0) {
                 av_log(NULL, AV_LOG_ERROR, "Failed to open file '%s'\n",
                     vs->avf->url);
-                av_free(old_filename);
                 return ret;
             }
             write_styp(vs->out);
             ret = flush_dynbuf(vs, &range_length);
             if (ret < 0) {
-                av_free(old_filename);
                 return ret;
             }
             ff_format_io_close(s, &vs->out);
         }
+
+        old_filename = av_strdup(vs->avf->url);
+        if (!old_filename) {
+            return AVERROR(ENOMEM);
+        }
+
         ret = hls_append_segment(s, hls, vs, vs->duration, vs->start_pos, vs->size);
         vs->start_pos = new_start_pos;
         if (ret < 0) {
@@ -2316,6 +2316,12 @@ failed:
 
         if ((hls->flags & HLS_TEMP_FILE) && oc->url[0]) {
             hls_rename_temp_file(s, oc);
+            av_free(old_filename);
+            old_filename = av_strdup(vs->avf->url);
+
+            if (!old_filename) {
+                return AVERROR(ENOMEM);
+            }
         }
 
         /* after av_write_trailer, then duration + 1 duration per packet */