[Bug 13958] New: Services: handle null display names properly when populating SCM db entries

http://bugs.winehq.org/show_bug.cgi?id=13958

Summary: Services: handle null display names properly when
                    populating SCM db entries
           Product: Wine
           Version: 1.0-rc5
          Platform: PC
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: programs
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

Hello,

there is a bug in services code when one or more services have no display name
set (null).
If CreateServiceW() is called, it checks for existing services using 
scmdatabase_find_service_by_displayname().
Unfortunately this internal helper doesn't handle the "null" service name
properly while iterating, resulting in exception and messy side effects
(although mapped to rpc exception it isn't propagated properly).

Following is service db dump with such cases:

--- snip ---
000d:trace:service:scmdatabase_load_services Loading service L"BITS"
000d:trace:service:load_service_config Image path           = L"svchost.exe -k
netsvcs"
000d:trace:service:load_service_config Group                = (null)
000d:trace:service:load_service_config Service account name = L"LocalSystem"
000d:trace:service:load_service_config Display name         = L"BITS"
000d:trace:service:load_service_config Service dependencies : (none)
000d:trace:service:load_service_config Group dependencies   : (none)
000d:trace:service:scmdatabase_load_services Loading service L"MountMgr"
000d:trace:service:load_service_config Image path           =
L"C:\windows\system32\drivers\mountmgr.sys"
000d:trace:service:load_service_config Group                = (null)
000d:trace:service:load_service_config Service account name = L"LocalSystem"
000d:trace:service:load_service_config Display name         = L"Mount Manager"
000d:trace:service:load_service_config Service dependencies : (none)
000d:trace:service:load_service_config Group dependencies   : (none)
000d:trace:service:scmdatabase_load_services Loading service L"MSIServer"
000d:trace:service:load_service_config Image path           =
L"C:\windows\system32\msiexec.exe /V"
000d:trace:service:load_service_config Group                = (null)
000d:trace:service:load_service_config Service account name = L"LocalSystem"
000d:trace:service:load_service_config Display name         = L"MSIServer"
000d:trace:service:load_service_config Service dependencies : (none)
000d:trace:service:load_service_config Group dependencies   : (none)
000d:trace:service:scmdatabase_load_services Loading service L"PnkBstrA"
000d:trace:service:load_service_config Image path           =
L"C:\windows\system32\PnkBstrA.exe"
000d:trace:service:load_service_config Group                = (null)
000d:trace:service:load_service_config Service account name = L"LocalSystem"
000d:trace:service:load_service_config Display name         = L"PnkBstrA"
000d:trace:service:load_service_config Service dependencies : (none)
000d:trace:service:load_service_config Group dependencies   : (none)
000d:trace:service:scmdatabase_load_services Loading service L"PnkBstrB"
000d:trace:service:load_service_config Image path           =
L"C:\windows\system32\PnkBstrB.exe"
000d:trace:service:load_service_config Group                = (null)
000d:trace:service:load_service_config Service account name = L"LocalSystem"
000d:trace:service:load_service_config Display name         = L"PnkBstrB"
000d:trace:service:load_service_config Service dependencies : (none)
000d:trace:service:load_service_config Group dependencies   : (none)
000d:trace:service:scmdatabase_load_services Loading service L"PnkBstrK"
000d:trace:service:load_service_config Image path           =
L"C:\windows\system32\drivers\PnkBstrK.sys"
000d:trace:service:load_service_config Group                = (null)
000d:trace:service:load_service_config Service account name = L"LocalSystem"
000d:trace:service:load_service_config Display name         = L"PnkBstrK"
000d:trace:service:load_service_config Service dependencies : (none)
000d:trace:service:load_service_config Group dependencies   : (none)
000d:trace:service:scmdatabase_load_services Loading service L"PROCMON13"
000d:trace:service:load_service_config Image path           =
L"\??\C:\windows\system32\Drivers\PROCMON13.SYS"
000d:trace:service:load_service_config Group                = (null)
000d:trace:service:load_service_config Service account name = (null)
000d:trace:service:load_service_config Display name         = (null)
000d:trace:service:load_service_config Service dependencies : (none)
000d:trace:service:load_service_config Group dependencies   : (none)
000d:trace:service:scmdatabase_load_services Loading service L"SecDrv"
000d:trace:service:load_service_config Image path           =
L"C:\windows\system32\drivers\\SECDRV.SYS"
000d:trace:service:load_service_config Group                = (null)
000d:trace:service:load_service_config Service account name = L"LocalSystem"
000d:trace:service:load_service_config Display name         = L"SecDrv"
000d:trace:service:load_service_config Service dependencies : (none)
000d:trace:service:load_service_config Group dependencies   : (none)
000d:trace:service:scmdatabase_load_services Loading service L"Spooler"
000d:trace:service:load_service_config Image path           =
L"C:\windows\system32\spoolsv.exe"
000d:trace:service:load_service_config Group                = L"SpoolerGroup"
000d:trace:service:load_service_config Service account name = L"LocalSystem"
000d:trace:service:load_service_config Display name         = L"Print Spooler"
000d:trace:service:load_service_config Service dependencies : (none)
000d:trace:service:load_service_config Group dependencies   : (none)
000d:trace:service:scmdatabase_load_services Loading service L"VxD"
000d:trace:service:load_service_config Image path           = (null)
000d:trace:service:load_service_config Group                = (null)
000d:trace:service:load_service_config Service account name = (null)
000d:trace:service:load_service_config Display name         = (null)
000d:trace:service:load_service_config Service dependencies : (none)
000d:trace:service:load_service_config Group dependencies   : (none) 
--- snip ---

Quick fix:

--- snip ---

diff --git a/programs/services/services.c b/programs/services/services.c
index 806fbb6..d48c985 100644
--- a/programs/services/services.c
+++ b/programs/services/services.c
@@ -341,7 +341,7 @@ struct service_entry
*scmdatabase_find_service_by_displayname(struct scmdatabase

LIST_FOR_EACH_ENTRY(service, &db->services, struct service_entry, entry)
     {
-        if (strcmpiW(name, service->config.lpDisplayName) == 0)
+        if (service->config.lpDisplayName && strcmpiW(name,
service->config.lpDisplayName) == 0)
             return service;
     }

--- snip ---

Hopefully it's not too late for 1.0 ;-|

Regards