always allow to cancel eraser mode

Fix for https://gna.org/bugs/index.php?18616

And a similar problem fixed by this commit:
<liquidApe> in trunk - draw some, press 'e' to go into eraser mode, then
flip pen over and erase some, then flip pen back over, it will flip back
into the 'e' eraser. Press 'e' again to toggle out of eraser mode and
note you can't get out of eraser mode

diff --git a/gui/brushmodifier.py b/gui/brushmodifier.py
index ee5ce11..7eba8e5 100644 (file)
--- a/gui/brushmodifier.py
+++ b/gui/brushmodifier.py
@@ -105,10 +105,9 @@ class BrushModifier:
         If `override` is true, the named setting will be forced to a base value
         greater than 0.9, and if it is false a base value less than 0.1 will be
         applied. Where possible, values from the base brush will be used. The
-        setting from `unmodified_brushinfo`, including any nonlinear
-        components, will be used if its base value is suitably large (or
-        small). If not, a base value of either 1 or 0 and no nonlinear
-        components will be applied.
+        setting from `unmodified_brushinfo`, including any input mapping, will
+        be used if its base value is suitably large (or small). If not, a base
+        value of either 1 or 0 and no input mapping will be applied.
         """
         unmod_b = self.unmodified_brushinfo
         modif_b = self.app.brush
@@ -184,12 +183,6 @@ class BrushModifier:
                     self._set_radius_internal(r + dr)
             self._push_hist(action)
         else:
-            if self._brush_is_dedicated_eraser():
-                # No, you may not leave eraser mode with one of these.
-                action.block_activate()
-                action.set_active(True)
-                action.unblock_activate()
-                return
             if not self._in_brush_selected_cb:
                 # We're leaving eraser mode because the user deactivated the
                 # ToggleAction, not because the brush changed. Might have to