avformat/rtsp: fix leading space in RTSP reason

When parsing the RTSP message reason, the whole remainder
after parsing the status code was used, which would lead to
a leading space in the parsed reason string.

(cherry picked from commit e63e040f0c)
Signed-off-by: Marvin Scholz <epirat07@gmail.com>

libavformat/http.c

@@ -24,6 +24,7 @@
 #include "config.h"
 #include "config_components.h"
 
+#include <string.h>
 #include <time.h>
 #if CONFIG_ZLIB
 #include <zlib.h>
@@ -214,7 +215,7 @@ static int http_open_cnx_internal(URLContext *h, AVDictionary **options)
     const char *path, *proxy_path, *lower_proto = "tcp", *local_path;
     char *env_http_proxy, *env_no_proxy;
     char *hashmark;
-    char hostname[1024], hoststr[1024], proto[10];
+    char hostname[1024], hoststr[1024], proto[10], tmp_host[1024];
     char auth[1024], proxyauth[1024] = "";
     char path1[MAX_URL_SIZE], sanitized_path[MAX_URL_SIZE + 1];
     char buf[1024], urlbuf[MAX_URL_SIZE];
@@ -224,7 +225,14 @@ static int http_open_cnx_internal(URLContext *h, AVDictionary **options)
     av_url_split(proto, sizeof(proto), auth, sizeof(auth),
                  hostname, sizeof(hostname), &port,
                  path1, sizeof(path1), s->location);
-    ff_url_join(hoststr, sizeof(hoststr), NULL, NULL, hostname, port, NULL);
+
+    av_strlcpy(tmp_host, hostname, sizeof(tmp_host));
+    // In case of an IPv6 address, we need to strip the Zone ID,
+    // if any. We do it at the first % sign, as percent encoding
+    // can be used in the Zone ID itself.
+    if (strchr(tmp_host, ':'))
+        tmp_host[strcspn(tmp_host, "%")] = '\0';
+    ff_url_join(hoststr, sizeof(hoststr), NULL, NULL, tmp_host, port, NULL);
 
     env_http_proxy = getenv_utf8("http_proxy");
     proxy_path = s->http_proxy ? s->http_proxy : env_http_proxy;

libavformat/rtsp.c

@@ -1239,9 +1239,12 @@ start:
         q = buf;
         for (;;) {
             ret = ffurl_read_complete(rt->rtsp_hd, &ch, 1);
+            if (ret != 1) {
+                ret = (ret < 0) ? ret : AVERROR(EIO);
+                av_log(s, AV_LOG_WARNING, "Failed reading RTSP data: %s\n", av_err2str(ret));
+                return ret;
+            }
             av_log(s, AV_LOG_TRACE, "ret=%d c=%02x [%c]\n", ret, ch, ch);
-            if (ret != 1)
-                return ret < 0 ? ret : AVERROR(EIO);
             if (ch == '\n')
                 break;
             if (ch == '$' && q == buf) {
@@ -1271,6 +1274,7 @@ start:
             if (!strncmp(buf1, "RTSP/", 5)) {
                 get_word(buf1, sizeof(buf1), &p);
                 reply->status_code = atoi(buf1);
+                p += strspn(p, SPACE_CHARS);
                 av_strlcpy(reply->reason, p, sizeof(reply->reason));
             } else {
                 av_strlcpy(reply->reason, buf1, sizeof(reply->reason)); // method