wineboot: Create serial comm registry keys

[André Hentschel]

Am 12.02.2016 um 21:26 schrieb Sebastian Lackner:
> On 12.02.2016 20:15, André Hentschel wrote:
>> Am 12.02.2016 um 09:46 schrieb Sebastian Lackner:
>>> On 12.02.2016 00:32, André Hentschel wrote:
>>>> Signed-off-by: André Hentschel <nerv at dawncrow.de>
>>>> ---
>>>>
>>>> For https://bugs.winehq.org/show_bug.cgi?id=11811
>>>>
>>>>
>>>>  programs/wineboot/wineboot.c | 39 +++++++++++++++++++++++++++++++++++++++
>>>>  1 file changed, 39 insertions(+)
>>>>
>>>
>>> Are you sure there are no keys for com ports >= 10? In general, such serial ports are
>>> also possible.
>>
>> In other places the symlink method seems to be limited from 1 to 9 (e.g. QueryDosDeviceW)
>>
>>> Nevertheless, more important: If I don't miss anything, the user still has to manually
>>> create a symlink in dosdevices/, otherwise this method will not work. Accessing serial
>>> ports on the other hand doesn't require any manual configuration when
>>> get_default_com_device() recognizes them (and the user has access). What is the benefit
>>> when it still requires manual user interaction?
>>
>> I think get_default_com_device() isn't a normal way to use com ports in Wine.
>> For example, I have /dev/ttyS0 to 31, most likely announced by my laptop motherboard, but would never intend to use those ports, which are not wired out.
>> Normal usecase would be to plug in a USB-Serial-Adapter and make a symlink to e.g. /dev/ttyUSB0
>>
>>
> 
> Well, but this depends on the exact use-case. I guess the forwarding of /dev/ttyS* was not
> added just for fun, but because its useful for at least some people. What about adding an
> explicit test which uses kernel32/ntdll functions, so that all serial ports are added to the
> registry? To do that, it would be necessary to make the /dev/ttyS* detection a bit more strict,
> like Alex Henrie tried to do with one of his patches:
> 
> https://github.com/wine-compholio/wine-staging/blob/master/patches/ntdll-Serial_Port_Detection/0001-ntdll-Do-a-device-check-before-returning-a-default-s.patch
> 

I like your idea and the patch.
What about something simpler like:


diff --git a/dlls/ntdll/directory.c b/dlls/ntdll/directory.c
index 93fe594..c5fd654 100644
--- a/dlls/ntdll/directory.c
+++ b/dlls/ntdll/directory.c
@@ -329,7 +329,7 @@ static void flush_dir_queue(void)
  */
 static char *get_default_com_device( int num )
 {
-    char *ret = NULL;
+    char *ret;
 
     if (num < 1 || num > 256) return NULL;
 #ifdef linux
@@ -346,7 +346,15 @@ static char *get_default_com_device( int num )
     sprintf( ret, "/dev/cuaa%d", num - 1 );
 #else
     FIXME( "no known default for device com%d\n", num );
+    return NULL;
 #endif
+
+    if (access( ret, R_OK | W_OK ))
+    {
+        RtlFreeHeap( GetProcessHeap(), 0, ret );
+        return NULL;
+    }
+
     return ret;
 }