fix selection and cursor

src/canvas.h

@@ -175,6 +175,8 @@ public:
     bool m_dirty_face[6] = SIXPLETTE(false);
     Layer m_smask; // selection mask
     bool m_smask_active = false;
+    // mode 0=none, 1=free, 2=line
+    int m_smask_mode = 0;
     RTT m_tmp[6];
     RTT m_tmp_dual[6];
     RTT m_mixer;
@@ -213,7 +215,7 @@ public:
         auto prev = I->m_current_mode;
         if (I->m_mode)
             for (auto& m : *I->m_mode)
-                m->leave();
+                m->leave(mode);
         I->m_mode = &modes[(int)mode];
         I->m_current_mode = mode;
         if (I->m_mode)