[Libreoffice-commits] core.git: Branch 'distro/collabora/cp-5.3-desktop' - sal/osl

[Mike Kaganski]

 sal/osl/w32/pipe.c |    8 ++++++++
 1 file changed, 8 insertions(+)

New commits:
commit 461ef62f514a5e7c88e5087cffda88d9535cef16
Author: Mike Kaganski <mike.kaganski at collabora.com>
Date:   Mon Jan 29 16:24:24 2018 +0300

    tdf#49134 tdf#114466 Transfer privilege to become foreground process
    
    ... to already open soffice process from newly spawned one on Windows.
    
    When an application takes user input, a timeout is started during
    which other processes cannot create foreground windows that might
    steal focus, and thus interrupt user input. The timeout is defined
    by SPI_SETFOREGROUNDLOCKTIMEOUT (see SystemParametersInfo) and
    ForegroundLockTimeout registry setting (see
    https://technet.microsoft.com/en-us/library/cc957208). If an
    application that currently doesn't have right to become foreground
    tries to show popups in this interval, the popup will stay on
    background, and only flash in taskbar.
    
    The application that has the right to steal focus (see the list in
    https://msdn.microsoft.com/en-us/library/ms632668) may transfer its
    right to another process using AllowSetForegroundWindow function.
    So, the intended effect is this:
    
    1. User interacts with some foreground process (e.g., Explorer);
       a timeout is started to prevent non-privileged processes from
       stealing focus;
    2. As the result, the process launches a new soffice process, which
       has privilege to create foreground windows (as it is started by
       foreground process);
    3. It communicates with already started soffice process, which is
       currently in background, and so doesn't have privilege to create
       foreground windows until timeout expires;
    4. It transfers its right to the already started soffice process,
       and then issues the required commands that might lead to need to
       show popup windows.
    
    Change-Id: I4208665c2ae4106fa06e72269f4c3804af40d582
    Reviewed-on: https://gerrit.libreoffice.org/48852
    Reviewed-by: Andras Timar <andras.timar at collabora.com>
    Tested-by: Andras Timar <andras.timar at collabora.com>

diff --git a/sal/osl/w32/pipe.c b/sal/osl/w32/pipe.c
index 7693a25b6196..4f5e7c9a10ac 100644
--- a/sal/osl/w32/pipe.c
+++ b/sal/osl/w32/pipe.c
@@ -234,6 +234,14 @@ oslPipe SAL_CALL osl_createPipe(rtl_uString *strPipeName, oslPipeOptions Options
                     rtl_uString_release( name );
                     rtl_uString_release( path );
 
+                    // We should try to transfer our privilege to become foreground process
+                    // to the other process, so that it may show popups (otherwise, they might
+                    // be blocked by SPI_GETFOREGROUNDLOCKTIMEOUT setting -
+                    // see SystemParametersInfo function at MSDN
+                    ULONG ServerProcessId = 0;
+                    if (GetNamedPipeServerProcessId(pPipe->m_File, &ServerProcessId))
+                        AllowSetForegroundWindow(ServerProcessId);
+
                     return pPipe;
                 }
                 else