[Spice-devel] [PATCH VDAgent-win] Initialize buffers before querying display config

[Sameeh Jubran]

The buffers and buffer sizes should be initialized and allocated. This
patch fixies a possible case where vdagent can get stuck, as the
function _pfnQueryDisplayConfig can return ERROR_INVALID_PARAMETER
if the buffers aren't intialized.
The call to free_config_buffers is superfluous becuase it is called
inside get_config_buffers.

Signed-off-by: Sameeh Jubran <sameeh at daynix.com>
---
 vdagent/display_configuration.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/vdagent/display_configuration.cpp b/vdagent/display_configuration.cpp
index bab4c95..409725e 100644
--- a/vdagent/display_configuration.cpp
+++ b/vdagent/display_configuration.cpp
@@ -700,7 +700,9 @@ CCD::~CCD()
 bool CCD::query_display_config()
 {
     LONG query_error(ERROR_SUCCESS);
-
+    if (!get_config_buffers()) {
+        return false;
+    }
     //Until we get it or error != ERROR_INSUFFICIENT_BUFFER
     do {
         query_error = _pfnQueryDisplayConfig(QDC_ALL_PATHS, &_numPathElements, _pPathInfo,
@@ -711,9 +713,9 @@ bool CCD::query_display_config()
         //(see https://msdn.microsoft.com/en-us/library/windows/hardware/ff569215(v=vs.85).aspx )
         if (query_error) {
              if (query_error == ERROR_INSUFFICIENT_BUFFER) {
-                free_config_buffers();
-                if (!get_config_buffers())
+                if (!get_config_buffers()) {
                     return false;
+                }
             } else {
                 vd_printf("%s failed QueryDisplayConfig with 0x%lx", __FUNCTION__, query_error);
                 return false;
-- 
2.7.4