msi:MsiGetUserInfo fix

[Aric Stewart]

do not crash if org, user or serial are not present. instead return the 
correct USERINFOSTATE_ABSENT value.
fixes a crash with excel viewer 2003
---
  dlls/msi/msi.c |   32 +++++++++++++++++++++++---------
  1 files changed, 23 insertions(+), 9 deletions(-)
-------------- next part --------------
diff --git a/dlls/msi/msi.c b/dlls/msi/msi.c
index 2cb4848..9887fbe 100644
--- a/dlls/msi/msi.c
+++ b/dlls/msi/msi.c
@@ -1562,15 +1562,29 @@ static USERINFOSTATE WINAPI MSI_GetUserI
 
     state = USERINFOSTATE_PRESENT;
 
-    r = msi_strcpy_to_awstring( user, lpUserNameBuf, pcchUserNameBuf );
-    if (r == ERROR_MORE_DATA)
-        state = USERINFOSTATE_MOREDATA;
-    r = msi_strcpy_to_awstring( org, lpOrgNameBuf, pcchOrgNameBuf );
-    if (r == ERROR_MORE_DATA)
-        state = USERINFOSTATE_MOREDATA;
-    r = msi_strcpy_to_awstring( serial, lpSerialBuf, pcchSerialBuf );
-    if (r == ERROR_MORE_DATA)
-        state = USERINFOSTATE_MOREDATA;
+    if (user)
+    {
+        r = msi_strcpy_to_awstring( user, lpUserNameBuf, pcchUserNameBuf );
+        if (r == ERROR_MORE_DATA)
+            state = USERINFOSTATE_MOREDATA;
+    }
+    else
+        state = USERINFOSTATE_ABSENT;
+    if (org)
+    {
+        r = msi_strcpy_to_awstring( org, lpOrgNameBuf, pcchOrgNameBuf );
+        if (r == ERROR_MORE_DATA && state == USERINFOSTATE_PRESENT)
+            state = USERINFOSTATE_MOREDATA; 
+    }
+    /* msdn states: The user information is considered to be present even in the absence of a company name. */
+    if (serial)
+    {
+        r = msi_strcpy_to_awstring( serial, lpSerialBuf, pcchSerialBuf );
+        if (r == ERROR_MORE_DATA && state == USERINFOSTATE_PRESENT)
+            state = USERINFOSTATE_MOREDATA;
+    }
+    else
+        state = USERINFOSTATE_ABSENT;
 
     msi_free( user );
     msi_free( org );