winhttp: Always return result at once if available in WinHttpReadData().

dlls/winhttp/request.c

@@ -3213,7 +3213,7 @@ BOOL WINAPI WinHttpReadData( HINTERNET hrequest, void *buffer, DWORD to_read, DW
     DWORD ret;
     struct request *request;
     BOOL async;
-    BOOL wont_block;
+    BOOL wont_block = FALSE;
 
     TRACE( "%p, %p, %lu, %p\n", hrequest, buffer, to_read, read );
 
@@ -3229,7 +3229,44 @@ BOOL WINAPI WinHttpReadData( HINTERNET hrequest, void *buffer, DWORD to_read, DW
         return FALSE;
     }
 
-    if ((async = request->connect->hdr.flags & WINHTTP_FLAG_ASYNC) && !skip_async_queue( request, &wont_block ))
+    if (!(async = request->connect->hdr.flags & WINHTTP_FLAG_ASYNC) || skip_async_queue( request, &wont_block ))
+    {
+        ret = read_data( request, buffer, to_read, read, async );
+    }
+    else if (wont_block)
+    {
+        /* Data available but recursion limit reached, only queue callback. */
+        struct send_callback *s;
+
+        if (!(s = malloc( sizeof(*s) )))
+        {
+            release_object( &request->hdr );
+            SetLastError( ERROR_OUTOFMEMORY );
+            return FALSE;
+        }
+
+        if (!(ret = read_data( request, buffer, to_read, &s->count, FALSE )))
+        {
+            if (read) *read = s->count;
+            s->status = WINHTTP_CALLBACK_STATUS_READ_COMPLETE;
+            s->info = buffer;
+            s->buflen = s->count;
+        }
+        else
+        {
+            s->result.dwResult = API_READ_DATA;
+            s->result.dwError  = ret;
+            s->status = WINHTTP_CALLBACK_STATUS_REQUEST_ERROR;
+            s->info = &s->result;
+            s->buflen = sizeof(s->result);
+        }
+
+        if ((ret = queue_task( &request->queue, task_send_callback, &s->task_hdr, &request->hdr )))
+            free( s );
+        else
+            ret = ERROR_IO_PENDING;
+    }
+    else
     {
         struct read_data *r;
 
@@ -3248,7 +3285,6 @@ BOOL WINAPI WinHttpReadData( HINTERNET hrequest, void *buffer, DWORD to_read, DW
         else
             ret = ERROR_IO_PENDING;
     }
-    else ret = read_data( request, buffer, to_read, read, async );
 
     release_object( &request->hdr );
     SetLastError( ret );

dlls/winhttp/tests/notification.c

@@ -1904,6 +1904,9 @@ static void CALLBACK test_recursion_callback( HINTERNET handle, DWORD_PTR contex
             break;
 
         case WINHTTP_CALLBACK_STATUS_DATA_AVAILABLE:
+        {
+            DWORD len;
+
             if (!context->read_from_callback)
             {
                 SetEvent( context->wait );
@@ -1920,13 +1923,18 @@ static void CALLBACK test_recursion_callback( HINTERNET handle, DWORD_PTR contex
                 "got %lu, thread %#lx\n", context->recursion_count, GetCurrentThreadId() );
             context->max_recursion_query = max( context->max_recursion_query, context->recursion_count );
             InterlockedIncrement( &context->recursion_count );
-            ret = WinHttpReadData( context->request, &b, 1, NULL );
+            b = 0xff;
+            len = 0xdeadbeef;
+            ret = WinHttpReadData( context->request, &b, 1, &len );
             err = GetLastError();
             ok( ret, "failed to read data, GetLastError() %lu\n", err );
             ok( err == ERROR_SUCCESS || err == ERROR_IO_PENDING, "got %lu\n", err );
+            ok( b != 0xff, "got %#x.\n", b );
+            ok( len == 1, "got %lu.\n", len );
             if (err == ERROR_SUCCESS) context->have_sync_callback = TRUE;
             InterlockedDecrement( &context->recursion_count );
             break;
+        }
 
         case WINHTTP_CALLBACK_STATUS_READ_COMPLETE:
         {