Merge lp:~vanvugt/compiz-core/backport-unredirection-fixes-0.9.7 into lp:compiz-core

[Daniel van Vugt]

Backport all the fixes from quantal required to support Unredirect
Fullscreen Windows mode reliably.
(LP: #980663) (LP: #1053902) (LP: #1041047) (LP: #1041066)
(LP: #1046661) (LP: #1047168) (LP: #1050749) (LP: #1051885)

This proposal is required by:
https://blueprints.launchpad.net/ubuntu/+spec/desktop-r-gaming-platform-unity-performance

Although, precise still has driver bugs so it's not turned on by default...
https://bugs.launchpad.net/ubuntu?field.tag=unredirect

[Daniel van Vugt (vanvugt)]

Ping

[Sam Spilsbury (smspillaz)]

This can be cleaned up slightly:

168 +include_directories (${GTEST_INCLUDE_DIRS} ..)
169 +set (exe "compiz_opengl_test_fsregion")
170 +add_executable (${exe} test-fsregion.cpp)
171 +target_link_libraries (${exe}
172 + compiz_opengl_fsregion
173 + compiz_core
174 + ${GTEST_BOTH_LIBRARIES}
175 +)
176 +#compiz_discover_tests(${exe} COVERAGE compiz_opengl_fsregion)
177 +gtest_add_tests (compiz_test_decor_clip_groups "" test-fsregion.cpp)

instead of ${exe} use compiz_opengl_test_fsregion.

Remove the commented out bit.

Other than that:

review: Approve

[Daniel van Vugt (vanvugt)]

Hmm, that looks like a copy/paste error:
176 +#compiz_discover_tests(${exe} COVERAGE compiz_opengl_fsregion)
177 +gtest_add_tests (compiz_test_decor_clip_groups "" test-fsregion.cpp)

review: Needs Fixing

[lp:~vanvugt/compiz-core/backport-unredirection-fixes-0.9.7]

3132. By Daniel van Vugt on 2012-11-14

Fix typos naming the wrong test.

[Daniel van Vugt (vanvugt)]

Fixed typos naming the wrong test. I noticed that 'make test' never reaches it though, despite the fact that the test is a real target that gets built and is in Makefile. Not yet sure why 'make test' doesn't know it's a test.

[Sam Spilsbury (smspillaz)]

On Wed, Nov 14, 2012 at 6:36 PM, Daniel van Vugt
<email address hidden> wrote:
> Fixed typos naming the wrong test. I noticed that 'make test' never reaches it though, despite the fact that the test is a real target that gets built and is in Makefile. Not yet sure why 'make test' doesn't know it's a test.

It is because gtest_discover_tests does not know how to handle
whitespace between the TEST and the ()

You need to do

TEST()

and not

TEST ()

(compiz_discover_tests was to solve this problem and many more, but
its obviously not in compiz-core)

> --
> https://code.launchpad.net/~vanvugt/compiz-core/backport-unredirection-fixes-0.9.7/+merge/133883
> You are reviewing the proposed merge of lp:~vanvugt/compiz-core/backport-unredirection-fixes-0.9.7 into lp:compiz-core.

--
Sam Spilsbury

[Daniel van Vugt (vanvugt)]

Don't know. The test cases pass if run directly:
   build/plugins/opengl/src/fsregion/tests/compiz_opengl_test_fsregion
but 'make test' doesn't find it. Not a blocker right now.

review: Approve

[Sam Spilsbury (smspillaz)]

Well, you can fix it fairly easily. Just remove the whitespace :)

Might as well, it will take thirty seconds to do.

On Wed, Nov 14, 2012 at 7:06 PM, Daniel van Vugt
<email address hidden> wrote:
> Review: Approve
>
> Don't know. The test cases pass if run directly:
> build/plugins/opengl/src/fsregion/tests/compiz_opengl_test_fsregion
> but 'make test' doesn't find it. Not a blocker right now.
> --
> https://code.launchpad.net/~vanvugt/compiz-core/backport-unredirection-fixes-0.9.7/+merge/133883
> You are reviewing the proposed merge of lp:~vanvugt/compiz-core/backport-unredirection-fixes-0.9.7 into lp:compiz-core.

--
Sam Spilsbury

[Sam Spilsbury (smspillaz)]

(might as well remove the whitespace)

review: Approve

[Daniel van Vugt (vanvugt)]

Hmm, yes that makes sense. Especially since macros require no space in their definition. Because the preprocessor has a much smaller brain than a compiler and macros are quite different to functions anyway. Though I heard cpp was Turing complete :)

[Daniel van Vugt (vanvugt)]

review: Needs Fixing

[lp:~vanvugt/compiz-core/backport-unredirection-fixes-0.9.7]

3133. By Daniel van Vugt on 2012-11-15

test-fsregion.cpp: Remove space in "TEST (" syntax so that gtest_add_tests
can parse them correctly :P

[Daniel van Vugt (vanvugt)]

OK, the tests now run. And I'm a little bit sad about having to introduce potential future conflicts to do so.

review: Approve

[Sam Spilsbury (smspillaz)]

Well, gtest_add_tests is a sed script, and the script requires a that
there be no space between TEST_F and TEST and the ().

It also does not support TEST_P or TYPED_TEST :(

On Thu, Nov 15, 2012 at 9:43 AM, Daniel van Vugt
<email address hidden> wrote:
> Hmm, yes that makes sense. Especially since macros require no space in their definition. Because the preprocessor has a much smaller brain than a compiler and macros are quite different to functions anyway. Though I heard cpp was Turing complete :)
> --
> https://code.launchpad.net/~vanvugt/compiz-core/backport-unredirection-fixes-0.9.7/+merge/133883
> You are reviewing the proposed merge of lp:~vanvugt/compiz-core/backport-unredirection-fixes-0.9.7 into lp:compiz-core.

--
Sam Spilsbury

=== modified file 'plugins/opengl/CMakeLists.txt'
--- plugins/opengl/CMakeLists.txt	2009-03-15 05:09:18 +0000
+++ plugins/opengl/CMakeLists.txt	2012-11-15 02:07:24 +0000
@@ -2,7 +2,9 @@
 
 include (CompizPlugin)
 
+add_subdirectory (src/fsregion)
+
 find_package (OpenGL)
 if (OPENGL_FOUND)
-    compiz_plugin(opengl PLUGINDEPS composite LIBRARIES ${OPENGL_gl_LIBRARY} INCDIRS ${OPENGL_INCLUDE_DIR})
-endif ()
\ No newline at end of file
+    compiz_plugin(opengl PLUGINDEPS composite LIBRARIES ${OPENGL_gl_LIBRARY} compiz_opengl_fsregion INCDIRS ${OPENGL_INCLUDE_DIR})
+endif ()

=== added directory 'plugins/opengl/src/fsregion'
=== added file 'plugins/opengl/src/fsregion/CMakeLists.txt'
--- plugins/opengl/src/fsregion/CMakeLists.txt	1970-01-01 00:00:00 +0000
+++ plugins/opengl/src/fsregion/CMakeLists.txt	2012-11-15 02:07:24 +0000
@@ -0,0 +1,7 @@
+if (COMPIZ_BUILD_TESTING)
+add_subdirectory (tests)
+endif ()
+
+add_library (compiz_opengl_fsregion STATIC fsregion.cpp)
+target_link_libraries (compiz_opengl_fsregion compiz_core)
+

=== added file 'plugins/opengl/src/fsregion/fsregion.cpp'
--- plugins/opengl/src/fsregion/fsregion.cpp	1970-01-01 00:00:00 +0000
+++ plugins/opengl/src/fsregion/fsregion.cpp	2012-11-15 02:07:24 +0000
@@ -0,0 +1,64 @@
+/*
+ * Compiz opengl plugin, FullscreenRegion class
+ *
+ * Copyright (c) 2012 Canonical Ltd.
+ * Author: Daniel van Vugt <[e-mail]>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "fsregion.h"
+
+namespace compiz {
+namespace opengl {
+
+FullscreenRegion::FullscreenRegion (const CompRect &rect) :
+    untouched (rect),
+    orig (untouched)
+{
+}
+
+bool
+FullscreenRegion::isCoveredBy (const CompRegion &region, WinFlags flags)
+{
+    bool fullscreen = false;
+
+    if (!(flags & (Desktop | Alpha)) &&
+        region == untouched &&
+        region == orig)
+    {
+	fullscreen = true;
+    }
+
+    untouched -= region;
+
+    return fullscreen;
+}
+
+bool
+FullscreenRegion::allowRedirection (const CompRegion &region)
+{
+    /* Don't allow existing unredirected windows that cover this
+     * region to be redirected again as they were probably unredirected
+     * on another monitor */
+    return region.intersects (orig);
+}
+
+} // namespace opengl
+} // namespace compiz

=== added file 'plugins/opengl/src/fsregion/fsregion.h'
--- plugins/opengl/src/fsregion/fsregion.h	1970-01-01 00:00:00 +0000
+++ plugins/opengl/src/fsregion/fsregion.h	2012-11-15 02:07:24 +0000
@@ -0,0 +1,58 @@
+/*
+ * Compiz opengl plugin, FullscreenRegion class
+ *
+ * Copyright (c) 2012 Canonical Ltd.
+ * Author: Daniel van Vugt <[e-mail]>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef __COMPIZ_OPENGL_FSREGION_H
+#define __COMPIZ_OPENGL_FSREGION_H
+#include "core/rect.h"
+#include "core/region.h"
+
+namespace compiz {
+namespace opengl {
+
+class FullscreenRegion
+{
+public:
+    typedef enum
+    {
+	Desktop = 1,
+	Alpha = 2
+    } WinFlag;
+
+    typedef unsigned int WinFlags;
+
+    FullscreenRegion (const CompRect &rect);
+
+    // isCoveredBy is called for windows from TOP to BOTTOM
+    bool isCoveredBy (const CompRegion &region, WinFlags flags = 0);
+    bool allowRedirection (const CompRegion &region);
+
+private:
+    CompRegion untouched;
+    CompRegion orig;
+};
+
+} // namespace opengl
+} // namespace compiz
+#endif

=== added directory 'plugins/opengl/src/fsregion/tests'
=== added file 'plugins/opengl/src/fsregion/tests/CMakeLists.txt'
--- plugins/opengl/src/fsregion/tests/CMakeLists.txt	1970-01-01 00:00:00 +0000
+++ plugins/opengl/src/fsregion/tests/CMakeLists.txt	2012-11-15 02:07:24 +0000
@@ -0,0 +1,10 @@
+include_directories (${GTEST_INCLUDE_DIRS} ..)
+set (exe "compiz_opengl_test_fsregion")
+add_executable (${exe} test-fsregion.cpp)
+target_link_libraries (${exe}
+    compiz_opengl_fsregion
+    compiz_core
+    ${GTEST_BOTH_LIBRARIES}
+)
+gtest_add_tests (compiz_opengl_test_fsregion "" ${CMAKE_CURRENT_SOURCE_DIR}/test-fsregion.cpp)
+

=== added file 'plugins/opengl/src/fsregion/tests/test-fsregion.cpp'
--- plugins/opengl/src/fsregion/tests/test-fsregion.cpp	1970-01-01 00:00:00 +0000
+++ plugins/opengl/src/fsregion/tests/test-fsregion.cpp	2012-11-15 02:07:24 +0000
@@ -0,0 +1,160 @@
+/*
+ * Compiz opengl plugin, FullscreenRegion class
+ *
+ * Copyright (c) 2012 Canonical Ltd.
+ * Author: Daniel van Vugt <[e-mail]>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "gtest/gtest.h"
+#include "fsregion.h"
+
+using namespace compiz::opengl;
+
+TEST(OpenGLFullscreenRegion, NoWindows)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+
+TEST(OpenGLFullscreenRegion, OneFullscreen)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_TRUE  (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+
+TEST(OpenGLFullscreenRegion, FullscreenNoDesktop)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_TRUE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+}
+
+TEST(OpenGLFullscreenRegion, AlphaFullscreen)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Alpha));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+
+TEST(OpenGLFullscreenRegion, AlphaOverFullscreen)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (50, 60, 70, 80),
+                                       FullscreenRegion::Alpha));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+
+TEST(OpenGLFullscreenRegion, NormalWindows)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (10, 10, 40, 30)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (20, 20, 50, 20)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+
+TEST(OpenGLFullscreenRegion, TwoFullscreen)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_TRUE  (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (10, 10, 40, 30)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (20, 20, 50, 20)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+
+TEST(OpenGLFullscreenRegion, Offscreen)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (-100, -100, 1, 1)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (2000, 2000, 123, 456)));
+    EXPECT_TRUE  (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (10, 10, 40, 30)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (20, 20, 50, 20)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+
+TEST(OpenGLFullscreenRegion, CancelFullscreen1)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (500, 500, 345, 234)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (10, 10, 40, 30)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (20, 20, 50, 20)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+
+TEST(OpenGLFullscreenRegion, CancelFullscreen2)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (-100, -100, 1, 1)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (2000, 2000, 123, 456)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (500, 500, 345, 234)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (10, 10, 40, 30)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (20, 20, 50, 20)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+
+TEST(OpenGLFullscreenRegion, Overflow)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (10, 10, 40, 30)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (-10, -10, 1044, 788)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+
+TEST(OpenGLFullscreenRegion, KeepUnredirectedStateIfNotOnMonitor)
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    CompRegion       window (1025, 0, 1024, 768);
+    /* Eg, not covering the monitor, should be redirected */
+    EXPECT_FALSE (monitor.isCoveredBy (window));
+    /* Don't allow the redirection however, because we weren't
+     * covering the monitor at all. */
+    EXPECT_FALSE (monitor.allowRedirection (window));
+}
+
+TEST(OpenGLFullscreenRegion, MaximizedWithDocks)  // LP: #1053902
+{
+    FullscreenRegion monitor (CompRect (0, 0, 1024, 768));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 24)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 24, 64, 744)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (64, 24, 960, 744)));
+    EXPECT_FALSE (monitor.isCoveredBy (CompRegion (0, 0, 1024, 768),
+                                       FullscreenRegion::Desktop));
+}
+

=== modified file 'plugins/opengl/src/paint.cpp'
--- plugins/opengl/src/paint.cpp	2012-03-19 09:19:04 +0000
+++ plugins/opengl/src/paint.cpp	2012-11-15 02:07:24 +0000
@@ -24,7 +24,9 @@
  */
 
 #include "privates.h"
+#include "fsregion/fsregion.h"
 
+#include <set>
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
@@ -37,6 +39,8 @@
 
 #define DEG2RAD (M_PI / 180.0f)
 
+using namespace compiz::opengl;
+
 GLScreenPaintAttrib defaultScreenPaintAttrib = {
     0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, -DEFAULT_Z_CAMERA
 };
@@ -210,12 +214,12 @@
     CompRegion    tmpRegion (region);
     CompWindow    *w;
     GLWindow      *gw;
-    int		  count, windowMask, odMask;
-    CompWindow	  *fullscreenWindow = NULL;
+    int           windowMask, odMask;
     bool          status, unredirectFS;
     bool          withOffset = false;
     GLMatrix      vTransform;
     CompPoint     offXY;
+    std::set<CompWindow*> unredirected;
 
     CompWindowList                   pl;
     CompWindowList::reverse_iterator rit;
@@ -226,12 +230,10 @@
     if (mask & PAINT_SCREEN_TRANSFORMED_MASK)
     {
 	windowMask     = PAINT_WINDOW_ON_TRANSFORMED_SCREEN_MASK;
-	count	       = 1;
     }
     else
     {
 	windowMask     = 0;
-	count	       = 0;
     }
 
     /*
@@ -243,6 +245,8 @@
 
     if (!(mask & PAINT_SCREEN_NO_OCCLUSION_DETECTION_MASK))
     {
+	FullscreenRegion fs (*output);
+
 	/* detect occlusions */
 	for (rit = pl.rbegin (); rit != pl.rend (); rit++)
 	{
@@ -303,29 +307,54 @@
 		}
 		else
 		    tmpRegion -= w->region ();
+	    }
 
-		/* unredirect top most fullscreen windows. */
-		if (count == 0 && unredirectFS)
+	    FullscreenRegion::WinFlags flags = 0;
+	    if (w->type () & CompWindowTypeDesktopMask)
+	        flags |= FullscreenRegion::Desktop;
+	    if (w->alpha ())
+		flags |= FullscreenRegion::Alpha;
+	    
+	    /*
+	     * Windows with alpha channels can partially occlude windows
+	     * beneath them and so neither should be unredirected in that case.
+	     */
+	    if (unredirectFS &&
+		!(mask & PAINT_SCREEN_TRANSFORMED_MASK) &&
+		!(mask & PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS_MASK) &&
+		fs.isCoveredBy (w->region (), flags))
+	    {
+		unredirected.insert (w);
+	    }
+	    else
+	    {
+		CompositeWindow *cw = CompositeWindow::get (w);
+		if (!cw->redirected ())
 		{
-		    if (w->region () == screen->region () &&
-			tmpRegion.isEmpty ())
+		    if (fs.allowRedirection (w->region ()))
 		    {
-			fullscreenWindow = w;
+			// 1. GLWindow::release to force gw->priv->needsRebind
+			gw->release ();
+
+			// 2. GLWindow::bind, which redirects the window,
+			//    rebinds the pixmap, and then rebinds the pixmap
+			//    to a texture.
+			gw->bind ();
+
+			// 3. Your window is now redirected again with the
+			//    latest pixmap contents.
 		    }
 		    else
 		    {
-			foreach (CompOutput &o, screen->outputDevs ())
-			    if (w->region () == CompRegion (o))
-				fullscreenWindow = w;
+			unredirected.insert (w);
 		    }
 		}
 	    }
-
-	    count++;
 	}
     }
 
-    if (fullscreenWindow)
+    /* Unredirect any redirected fullscreen windows */
+    foreach (CompWindow *fullscreenWindow, unredirected)
 	CompositeWindow::get (fullscreenWindow)->unredirect ();
 
     if (!(mask & PAINT_SCREEN_NO_BACKGROUND_MASK))
@@ -337,7 +366,7 @@
 	if (w->destroyed ())
 	    continue;
 
-	if (w == fullscreenWindow)
+	if (unredirected.find (w) != unredirected.end ())
 	    continue;
 
 	if (!w->shaded ())

=== added file 'tests/manual/Unredirect.txt'
--- tests/manual/Unredirect.txt	1970-01-01 00:00:00 +0000
+++ tests/manual/Unredirect.txt	2012-11-15 02:07:24 +0000
@@ -0,0 +1,97 @@
+WINDOW UNREDIRECTION TESTS
+===========================
+Daniel van Vugt <[e-mail]>
+
+
+Browser unredirect with context menus
+-------------------------------------
+Setup:
+#. Install Chromium or Chrome browser.
+ 
+Actions:
+#. Open Chrome/Chromium and hit F11 to go full screen.
+#. Right click on the web page to open a context menu.
+#. Left click on the web page to close the context menu.
+#. Right click on the web page to open a context menu.
+#. Left click on the web page to close the context menu.
+#. Press F11 to exit from full screen.
+
+Expected Result:
+  Every time you right-clicked, the context menu should be visible.
+
+
+Video unredirect with window menu
+---------------------------------
+Setup:
+#. Install mplayer.
+#. Get a video file you can play in mplayer.
+  
+Actions:
+#. Open the video in mplayer.
+#. Hit F to go fullscreen.
+#. Hit Alt+Space to open the window menu.
+#. Hit Escape to close the window menu.
+#. Hit Alt+Space to open the window menu.
+#. Hit Escape to close the window menu.
+#. Hit Escape to close the video.
+
+Expected Result:
+  Every time you hit Alt+Space the window menu should have appeared and the
+  video should still be playing behind it.
+
+
+Video unredirect with transformed screen
+----------------------------------------
+Setup:
+#. Install mplayer.
+#. Get a video file you can play in mplayer.
+  
+Actions:
+#. Open the video in mplayer.
+#. Hit F to go fullscreen.
+#. Trigger expo mode (Super+E or mouse to top-left corner)
+#. Leave expo mode (click on the full screen video)
+#. Trigger expo mode again.
+#. Leave expo mode (click on the full screen video)
+#. Hit Escape to close the video.
+
+Expected Result:
+  Every time you triggered expo mode, expo mode should have become visible and
+  you should see the video still playing in the expo view.
+
+
+Unredirect cancelation by alpha windows on top (LP: #1046661)
+-------------------------------------------------------------
+Setup:
+#. Install Chromium or Chrome browser.
+ 
+Actions:
+#. Open a Chrome/Chromium window.
+#. Open a gnome-terminal window (Ctrl+Alt+T)
+#. Move the gnome-terminal to the centre of the screen, above the Chrome
+   window.
+#. Click on the Chrome window and make it fullscreen (F11).
+#. Alt+Tab to the gnome-terminal window.
+
+Expected Result:
+  The gnome-terminal window should be visible on top.
+
+
+Unredirect cancelation by transformed windows (LP: #1047168)
+-------------------------------------------------------------
+Setup:
+#. Install Chromium or Chrome browser.
+#. Run ccsm and ensure the Scale plugin is loaded and "Initiate Window Picker"
+   is bound to Shift+Alt+Up.
+ 
+Actions:
+#. Open a Chrome/Chromium window.
+#. Open a gnome-terminal window (Ctrl+Alt+T)
+#. Move the gnome-terminal to the centre of the screen, above the Chrome
+   window.
+#. Click on the Chrome window and make it fullscreen (F11).
+#. Hold Shift+Alt and tap Up to engage scale mode. Keep holding Shift+Alt
+   for a few seconds.
+
+Expected Result:
+  Windows get scaled and you can see both the Chrome and Terminal windows.