Return nullptr if client is not found

Signed-off-by: Kazumasa Mitsunari <knimitz@witz-inc.co.jp>

1 files changed, 8 insertions, 1 deletions

diff --git a/src/applist.cpp b/src/applist.cpp
index 922a89e..888ab71 100644
--- a/src/applist.cpp
+++ b/src/applist.cpp
@@ -140,7 +140,14 @@ void AppList::removeSurface(unsigned surface){
  */
 shared_ptr<WMClient> AppList::lookUpClient(const string &appid)
 {
-    return this->app2client.at(appid);
+    if(this->app2client.count(appid) != 0)
+    {
+        return this->app2client.at(appid);
+    }
+    else
+    {
+        return nullptr;
+    }
 }
 
 /**