installer: auto-terminate ssh-agent.exe and friends

This background process is supposed to be auto-started, so it makes sense
to auto-terminate it.

We need to be careful, though, to report correctly when we could not
terminate the process, in which case we ask the user to please do it
themselves.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

installer/install.iss

@@ -469,6 +469,8 @@ begin
             Caption:=Processes[i].Name+' (PID '+IntToStr(Processes[i].ID);
             if Processes[i].Restartable then begin
                 Caption:=Caption+', closing is optional';
+            end else if Processes[i].ToTerminate then begin
+                Caption:=Caption+', will be terminated';
             end else begin
                 Caption:=Caption+', closing is required';
                 ManualClosingRequired:=True;
@@ -1201,17 +1203,17 @@ end;
 
 function ShouldSkipPage(PageID:Integer):Boolean;
 begin
-#ifdef DEBUG_WIZARD_PAGE
-    Result:=PageID<>DebugWizardPage
-    Exit;
-#endif
     if (ProcessesPage<>NIL) and (PageID=ProcessesPage.ID) then begin
         // This page is only reached forward (by pressing "Next", never by pressing "Back").
         RefreshProcessList(NIL);
         Result:=(GetArrayLength(Processes)=0);
     end else begin
         Result:=False;
     end;
+#ifdef DEBUG_WIZARD_PAGE
+    Result:=PageID<>DebugWizardPage
+    Exit;
+#endif
 end;
 
 procedure CurPageChanged(CurPageID:Integer);
@@ -1273,7 +1275,14 @@ begin
         // It would have been nicer to just disable the "Next" button, but the
         // WizardForm exports the button just read-only.
         for i:=0 to GetArrayLength(Processes)-1 do begin
-            if not Processes[i].Restartable then begin
+            if Processes[i].ToTerminate then begin
+	        if not TerminateProcessByID(Processes[i].ID) then begin
+                    SuppressibleMsgBox('Failed to terminate '+Processes[i].Name+' (pid '+IntToStr(Processes[i].ID)+')'+#13+'Please terminate it manually and press the "Refresh" button.',mbCriticalError,MB_OK,IDOK);
+                    Result:=False;
+                    Exit;
+                end;
+		    ;
+            end else if not Processes[i].Restartable then begin
                 SuppressibleMsgBox(
                     'Setup cannot continue until you close at least those applications in the list that are marked as "closing is required".'
                 ,   mbCriticalError

installer/modules.inc.iss

@@ -37,9 +37,14 @@ const
     INVALID_HANDLE_VALUE = -1;
 
     // For OpenProcess().
+    PROCESS_TERMINATE         = $0001;
     PROCESS_VM_READ           = $0010;
     PROCESS_QUERY_INFORMATION = $0400;
+    SYNCHRONIZE               = $00100000;
 
+    // For WaitForSingleObject().
+    WAIT_TIMEOUT = $00000102;
+    WAIT_FAILED  = $ffffffff;
 type
     HMODULE   = DWORD;
     LONG      = Longint;
@@ -52,7 +57,7 @@ type
     ProcessEntry=record
         ID:DWORD;
         Name:String;
-        Restartable:Boolean;
+        Restartable,ToTerminate:Boolean;
     end;
     ProcessList=array of ProcessEntry;
 
@@ -532,6 +537,8 @@ begin
                 Processes[Have].ID:=AppList[i].Process.dwProcessId;
                 Processes[Have].Name:=ArrayToString(AppList[i].strAppName);
                 Processes[Have].Restartable:=AppList[i].bRestartable;
+                if (Pos('ssh-add.exe',Processes[Have].Name)>0) or (Pos('ssh-agent.exe',Processes[Have].Name)>0) then
+		    Processes[Have].ToTerminate:=True;
             end;
             Result:=Handle;
         end;
@@ -654,3 +661,42 @@ begin
         Result:=True;
     end;
 end;
+
+function TerminateProcess(hProcess:THandle;uExitCode:UINT):Boolean;
+external '[email protected]';
+
+function WaitForSingleObject(hHandle:THandle;dwMilliseconds:DWORD):DWORD;
+external '[email protected]';
+
+function IsProcessRunning(dwProcessId:DWORD):Boolean;
+var
+    ProcList:IdList;
+    i:Integer;
+begin
+    if not GetProcessList(ProcList) then
+        Exit;
+    for i:=0 to GetArraylength(ProcList)-1 do
+        if dwProcessId=ProcList[i] then begin
+	    Result:=True;
+	    Exit;
+	end;
+    Result:=False;
+end;
+
+function TerminateProcessByID(dwProcessId:DWORD):Boolean;
+var
+    Process:THandle;
+    WaitResult:DWORD;
+begin
+    Process:=OpenProcess(SYNCHRONIZE or PROCESS_TERMINATE,False,dwProcessId);
+    if Process=0 then
+	Result:=not IsProcessRunning(dwProcessId)
+    else begin
+        Result:=TerminateProcess(Process,3)
+	if not Result then
+	    Exit;
+	WaitResult:=WaitForSingleObject(Process,5000);
+        Result:=(WaitResult<>WAIT_TIMEOUT) and (WaitResult<>WAIT_FAILED);
+	CloseHandle(Process);
+    end;
+end;