wininet: Add a new NETCON_query_data_available function.

Use it to implement the behaviour where InternetReadFileExA does a 
synchronous request if the data is available and asynchronous otherwise.

dlls/wininet/internet.c

@@ -1855,12 +1855,17 @@ BOOL WINAPI InternetReadFileExA(HINTERNET hFile, LPINTERNET_BUFFERSA lpBuffersOu
         return FALSE;
     }
 
-    /* FIXME: native only does it asynchronously if the amount of data
-     * requested isn't available. See NtReadFile. */
     /* FIXME: IRF_ASYNC may not be the right thing to test here;
-     * hIC->hdr.dwFlags & INTERNET_FLAG_ASYNC is probably better, but
-     * we should implement the above first */
+     * hIC->hdr.dwFlags & INTERNET_FLAG_ASYNC is probably better */
     if (dwFlags & IRF_ASYNC)
+    {
+        DWORD dwDataAvailable = 0;
+
+        if (lpwh->htype == WH_HHTTPREQ)
+            NETCON_query_data_available(&((LPWININETHTTPREQW)lpwh)->netConnection,
+                                        &dwDataAvailable);
+
+        if (!dwDataAvailable)
         {
             WORKREQUEST workRequest;
             struct WORKREQ_INTERNETREADFILEEXA *req;
@@ -1876,6 +1881,7 @@ BOOL WINAPI InternetReadFileExA(HINTERNET hFile, LPINTERNET_BUFFERSA lpBuffersOu
             INTERNET_SetLastError(ERROR_IO_PENDING);
             return FALSE;
         }
+    }
 
     retval = INTERNET_ReadFile(lpwh, lpBuffersOut->lpvBuffer,
         lpBuffersOut->dwBufferLength, &lpBuffersOut->dwBufferLength,
@@ -3258,15 +3264,24 @@ BOOL WINAPI InternetQueryDataAvailable( HINTERNET hFile,
     switch (lpwhr->hdr.htype)
     {
     case WH_HHTTPREQ:
-        if (!NETCON_recv(&lpwhr->netConnection, buffer,
+        if (NETCON_query_data_available(&lpwhr->netConnection,
+                                        lpdwNumberOfBytesAvailble))
+        {
+            if (!*lpdwNumberOfBytesAvailble &&
+                !NETCON_recv(&lpwhr->netConnection, buffer,
                          min(sizeof(buffer), lpwhr->dwContentLength - lpwhr->dwContentRead),
                          MSG_PEEK, (int *)lpdwNumberOfBytesAvailble))
             {
                 INTERNET_SetLastError(ERROR_NO_MORE_FILES);
                 retval = FALSE;
             }
-        else
             retval = TRUE;
+        }
+        else
+        {
+            INTERNET_SetLastError(ERROR_NO_MORE_FILES);
+            retval = FALSE;
+        }
         break;
 
     default:

dlls/wininet/internet.h

@@ -459,6 +459,7 @@ BOOL NETCON_send(WININET_NETCONNECTION *connection, const void *msg, size_t len,
 		int *sent /* out */);
 BOOL NETCON_recv(WININET_NETCONNECTION *connection, void *buf, size_t len, int flags,
 		int *recvd /* out */);
+BOOL NETCON_query_data_available(WININET_NETCONNECTION *connection, DWORD *available);
 BOOL NETCON_getNextLine(WININET_NETCONNECTION *connection, LPSTR lpszBuffer, LPDWORD dwBuffer);
 LPCVOID NETCON_GetCert(WININET_NETCONNECTION *connection);
 BOOL NETCON_set_timeout(WININET_NETCONNECTION *connection, BOOL send, int value);

dlls/wininet/netconnection.c

@@ -33,6 +33,9 @@
 #ifdef HAVE_UNISTD_H
 # include <unistd.h>
 #endif
+#ifdef HAVE_SYS_IOCTL_H
+# include <sys/ioctl.h>
+#endif
 #include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
@@ -569,6 +572,35 @@ BOOL NETCON_recv(WININET_NETCONNECTION *connection, void *buf, size_t len, int f
     }
 }
 
+/******************************************************************************
+ * NETCON_query_data_available
+ * Returns the number of bytes of peeked data plus the number of bytes of
+ * queued, but unread data.
+ */
+BOOL NETCON_query_data_available(WININET_NETCONNECTION *connection, DWORD *available)
+{
+    if (!NETCON_connected(connection))
+        return FALSE;
+
+    if (connection->peek_msg)
+        *available = connection->peek_len;
+    else
+        *available = 0;
+#ifdef FIONREAD
+    if (!connection->useSSL)
+    {
+        int unread;
+        int retval = ioctl(connection->socketFD, FIONREAD, &unread);
+        if (!retval)
+        {
+            TRACE("%d bytes of queued, but unread data\n", unread);
+            *available += unread;
+        }
+    }
+#endif
+    return TRUE;
+}
+
 /******************************************************************************
  * NETCON_getNextLine
  */