[PATCH] qga/vss-win32: Add VSS provider unregistration retry

[Elizabeth Ashurov]

This commit improves the QGA VSS provider installation flow
by attempting to unregister the VSS provider if it's already
found during installation. This allows for a retry of installation
even if a previous unregistration failed or was not performed.

Signed-off-by: Elizabeth Ashurov <eashu...@redhat.com>
---
 qga/vss-win32/install.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/qga/vss-win32/install.cpp b/qga/vss-win32/install.cpp
index 5cea5bcf74..a136d46050 100644
--- a/qga/vss-win32/install.cpp
+++ b/qga/vss-win32/install.cpp
@@ -263,6 +263,7 @@ STDAPI COMRegister(void)
     qga_debug_begin;
 
     HRESULT hr;
+    HRESULT unregisterHr;
     COMInitializer initializer;
     COMPointer<IUnknown> pUnknown;
     COMPointer<ICOMAdminCatalog2> pCatalog;
@@ -287,9 +288,13 @@ STDAPI COMRegister(void)
 
     chk(QGAProviderFind(QGAProviderCount, (void *)&count));
     if (count) {
-        errmsg(E_ABORT, "QGA VSS Provider is already installed");
-        qga_debug_end;
-        return E_ABORT;
+        qga_debug("QGA VSS Provider is already installed. Attempting to 
unregister first.");
+        unregisterHr = COMUnregister();
+        if (FAILED(unregisterHr)) {
+            errmsg(unregisterHr, "Failed to unregister existing QGA VSS 
Provider. Aborting installation.");
+            qga_debug_end;
+            return E_ABORT; 
+        }
     }
 
     chk(CoCreateInstance(CLSID_COMAdminCatalog, NULL, CLSCTX_INPROC_SERVER,
-- 
2.49.0