[PATCH 0/1] MR7451: dlls/shell32: Fix IUnknown::QueryInterface() to meet spec

[Edward OC (＠funfunctor)]

The spec says if the passed pointer is NULL then return E_POINTER
and not to just unconditionally deref then set NULL.

Signed-off-by: Edward O'Callaghan <edward(a)antitrust.cc>

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/7451

[PATCH 1/1] dlls/shell32: Fix IUnknown::QueryInterface() to meet spec

[Edward O'Callaghan]

From: Edward O'Callaghan <edward(a)antitrust.cc>

The spec says if the passed pointer is NULL then return E_POINTER
and not to just unconditionally deref then set NULL.

Signed-off-by: Edward O'Callaghan <edward(a)antitrust.cc>
---
 dlls/shell32/shelllink.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/dlls/shell32/shelllink.c b/dlls/shell32/shelllink.c
index 30cd038728f..9e18546b6af 100644
--- a/dlls/shell32/shelllink.c
+++ b/dlls/shell32/shelllink.c
@@ -1558,7 +1558,8 @@ static HRESULT WINAPI IShellLinkW_fnQueryInterface(
 
     TRACE("(%p)->(%s)\n", This, debugstr_guid(riid));
 
-    *ppvObj = NULL;
+    if (!ppvObj)
+        return E_POINTER;
 
     if(IsEqualIID(riid, &IID_IUnknown) || IsEqualIID(riid, &IID_IShellLinkA))
     {
@@ -1595,16 +1596,16 @@ static HRESULT WINAPI IShellLinkW_fnQueryInterface(
     else if(IsEqualIID(riid, &IID_IPropertyStore))
     {
         *ppvObj = &This->IPropertyStore_iface;
+    } else {
+        *ppvObj = NULL;
+        ERR("-- Interface: E_NOINTERFACE\n");
+        return E_NOINTERFACE;
     }
 
-    if(*ppvObj)
-    {
-        IUnknown_AddRef((IUnknown*)*ppvObj);
-        TRACE("-- Interface: (%p)->(%p)\n", ppvObj, *ppvObj);
-        return S_OK;
-    }
-    ERR("-- Interface: E_NOINTERFACE\n");
-    return E_NOINTERFACE;
+    IUnknown_AddRef((IUnknown*)*ppvObj);
+    TRACE("-- Interface: (%p)->(%p)\n", ppvObj, *ppvObj);
+
+    return S_OK;
 }
 
 /******************************************************************************
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/7451

[Nikolay Sivov (＠nsivov)]

This needs a test.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/7451#note_96303