Merge lp:~kdub/mir/fix-1483779-silo0 into lp:~mir-team/mir/silo0

[Kevin DuBois]

software cursor: avoid a situation where we would double-remove an input visual that had been hidden. Default behavior of ms::SurfaceStack on a double removal is to throw.

fixes: lp: #1483779

software cursor: avoid a situation where we would double-remove an input visual that had been hidden. Default behavior of ms::SurfaceStack on a double removal is to throw.

fixes: lp: #1483779

[Daniel van Vugt (vanvugt)]

This fix is not present on trunk (lp:mir). Don't we want to propose it there first? Or is it not a bug at all on trunk?

review: Needs Information

[Daniel van Vugt (vanvugt)]

Never mind. I just found your other MP and linked it to the bug.

review: Abstain

=== modified file 'src/server/graphics/software_cursor.cpp'
--- src/server/graphics/software_cursor.cpp	2015-06-17 05:20:42 +0000
+++ src/server/graphics/software_cursor.cpp	2015-08-11 15:00:41 +0000
@@ -136,7 +136,7 @@
 {
     std::shared_ptr<detail::CursorRenderable> new_renderable;
     std::shared_ptr<detail::CursorRenderable> old_renderable;
-
+    bool old_visibility = false;
     // Do a lock dance to make this function threadsafe,
     // while avoiding calling scene methods under lock
     {
@@ -145,6 +145,7 @@
         if (renderable)
             position = renderable->screen_position().top_left;
         new_renderable = create_renderable_for(cursor_image, position);
+        old_visibility = visible;
         visible = true;
     }
 
@@ -160,7 +161,7 @@
         hotspot = cursor_image.hotspot();
     }
 
-    if (old_renderable)
+    if (old_renderable && old_visibility)
         scene->remove_input_visualization(old_renderable);
 }
 

=== modified file 'tests/unit-tests/graphics/test_software_cursor.cpp'
--- tests/unit-tests/graphics/test_software_cursor.cpp	2015-06-17 05:20:42 +0000
+++ tests/unit-tests/graphics/test_software_cursor.cpp	2015-08-11 15:00:41 +0000
@@ -313,3 +313,18 @@
     cursor.show(another_stub_cursor_image);
     cursor.show(stub_cursor_image);
 }
+
+//lp: 1483779
+TEST_F(SoftwareCursor, doesnt_try_to_remove_after_hiding)
+{
+    using namespace testing;
+
+    EXPECT_CALL(mock_input_scene, add_input_visualization(_))
+        .Times(2);
+    EXPECT_CALL(mock_input_scene, remove_input_visualization(_))
+        .Times(1);
+    cursor.show(stub_cursor_image);
+    cursor.hide(); //should remove here
+    cursor.show(stub_cursor_image); //should add, but not remove a second time
+    Mock::VerifyAndClearExpectations(&mock_input_scene);
+}