[libsoup/wip/http2] body-input-stream-http2: try to read after emitting need-more-data signal

[Carlos Garcia Campos <carlosgc src gnome org>]

commit 049fe6a2574190d45779ae42f30fc25ae2406221
Author: Carlos Garcia Campos <cgarcia igalia com>
Date:   Mon May 17 15:22:56 2021 +0200

    body-input-stream-http2: try to read after emitting need-more-data signal
    
    We might have the data already available, the stream can even be
    completed at this point.

 libsoup/http2/soup-body-input-stream-http2.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)
---
diff --git a/libsoup/http2/soup-body-input-stream-http2.c b/libsoup/http2/soup-body-input-stream-http2.c
index 3fcc43e4..8c7fe2cc 100644
--- a/libsoup/http2/soup-body-input-stream-http2.c
+++ b/libsoup/http2/soup-body-input-stream-http2.c
@@ -216,19 +216,31 @@ soup_body_input_stream_http2_read_nonblocking (GPollableInputStream  *stream,
         gsize read = soup_body_input_stream_http2_read_real (G_INPUT_STREAM (stream), FALSE, buffer, count, 
NULL, &inner_error);
 
         if (read == 0 && !priv->completed && !inner_error) {
-                g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK, "Operation would block");
-
                 /* Try requesting more reads from the io backend */
                 GError *inner_error = NULL;
+
                 g_signal_emit (memory_stream, signals[NEED_MORE_DATA], 0,
                                NULL, FALSE, &inner_error);
 
-                // TODO: Do we care?
-                g_clear_error (&inner_error);
+                if (inner_error) {
+                        g_propagate_error (error, inner_error);
 
                         return -1;
                 }
 
+                if (priv->completed)
+                        return soup_body_input_stream_http2_read_real (G_INPUT_STREAM (stream), FALSE, 
buffer, count, NULL, error);
+
+                if (priv->pos < priv->len) {
+                        read = soup_body_input_stream_http2_read_real (G_INPUT_STREAM (stream), FALSE, 
buffer, count, NULL, NULL);
+                        if (read > 0)
+                                return read;
+                }
+
+                g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK, "Operation would block");
+                return -1;
+        }
+
         if (inner_error)
                 g_propagate_error (error, inner_error);
 
@@ -569,4 +581,4 @@ soup_body_input_stream_http2_class_init (SoupBodyInputStreamHttp2Class *klass)
                               NULL,
                               G_TYPE_ERROR,
                               2, G_TYPE_CANCELLABLE, G_TYPE_BOOLEAN);
-}
\ No newline at end of file
+}