[gimp] app: check if tool control is active before setting modifier state.

[Jehan Pagès <jehanp src gnome org>]

commit 33822c51c26412631206457a59eeae2a03c79a32
Author: Jehan <jehan girinstud io>
Date:   Wed Apr 4 00:26:41 2018 +0200

    app: check if tool control is active before setting modifier state.
    
    Similar to commit 845eb522b6, I had a CRITICAL which happened on a
    device_changed, triggering gimp_display_shell_update_focus(), this time
    in focus in.

 app/tools/tool_manager.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/app/tools/tool_manager.c b/app/tools/tool_manager.c
index 8fcf258..53f75be 100644
--- a/app/tools/tool_manager.c
+++ b/app/tools/tool_manager.c
@@ -413,7 +413,8 @@ tool_manager_modifier_state_active (Gimp            *gimp,
 
   tool_manager = tool_manager_get (gimp);
 
-  if (tool_manager->active_tool)
+  if (tool_manager->active_tool &&
+      ! gimp_tool_control_is_active (tool_manager->active_tool->control))
     {
       gimp_tool_set_modifier_state (tool_manager->active_tool,
                                     state,