http: handle ICY in presence of chunked transfer encoding

Some http servers send an ICY stream in combination with chunked
transfer encoding. This case was handled incorrectly by the ICY code:
instead of handling chunked encoding before anything ICY related, both
were mixed.

Fix this by separating the ICY code from normal http reading. Move the
normal http reading to a new function http_read_stream(), while
http_read() handles ICY on top of http_read_stream().

The server identified itself as: cloudflare-nginx

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/http.c

@@ -768,7 +768,6 @@ static int http_buf_read(URLContext *h, uint8_t *buf, int size)
     }
     if (len > 0) {
         s->off += len;
-        s->icy_data_read += len;
         if (s->chunksize > 0)
             s->chunksize -= len;
     }
@@ -807,7 +806,7 @@ static int http_buf_read_compressed(URLContext *h, uint8_t *buf, int size)
 }
 #endif
 
-static int http_read(URLContext *h, uint8_t *buf, int size)
+static int http_read_stream(URLContext *h, uint8_t *buf, int size)
 {
     HTTPContext *s = h->priv_data;
     int err, new_location;
@@ -842,6 +841,31 @@ static int http_read(URLContext *h, uint8_t *buf, int size)
         }
         size = FFMIN(size, s->chunksize);
     }
+#if CONFIG_ZLIB
+    if (s->compressed)
+        return http_buf_read_compressed(h, buf, size);
+#endif
+    return http_buf_read(h, buf, size);
+}
+
+// Like http_read_stream(), but no short reads.
+// Assumes partial reads are an error.
+static int http_read_stream_all(URLContext *h, uint8_t *buf, int size)
+{
+    int pos = 0;
+    while (pos < size) {
+        int len = http_read_stream(h, buf + pos, size - pos);
+        if (len < 0)
+            return len;
+        pos += len;
+    }
+    return pos;
+}
+
+static int http_read(URLContext *h, uint8_t *buf, int size)
+{
+    HTTPContext *s = h->priv_data;
+
     if (s->icy_metaint > 0) {
         int remaining = s->icy_metaint - s->icy_data_read; /* until next metadata packet */
         if (!remaining) {
@@ -849,17 +873,18 @@ static int http_read(URLContext *h, uint8_t *buf, int size)
             // which sets the length of the packet (divided by 16). If it's 0,
             // the metadata doesn't change. After the packet, icy_metaint bytes
             // of normal data follow.
-            int ch = http_getc(s);
-            if (ch < 0)
-                return ch;
+            uint8_t ch;
+            int len = http_read_stream_all(h, &ch, 1);
+            if (len < 1)
+                return len;
             if (ch > 0) {
                 char data[255 * 16 + 1];
-                int n;
                 int ret;
-                ch *= 16;
-                for (n = 0; n < ch; n++)
-                    data[n] = http_getc(s);
-                data[ch + 1] = 0;
+                len = ch * 16;
+                ret = http_read_stream_all(h, data, len);
+                if (ret < len)
+                    return ret;
+                data[len + 1] = 0;
                 if ((ret = av_opt_set(s, "icy_metadata_packet", data, 0)) < 0)
                     return ret;
             }
@@ -868,11 +893,10 @@ static int http_read(URLContext *h, uint8_t *buf, int size)
         }
         size = FFMIN(size, remaining);
     }
-#if CONFIG_ZLIB
-    if (s->compressed)
-        return http_buf_read_compressed(h, buf, size);
-#endif
-    return http_buf_read(h, buf, size);
+    size = http_read_stream(h, buf, size);
+    if (size > 0)
+        s->icy_data_read += size;
+    return size;
 }
 
 /* used only when posting data */