This bug affects Chromium only. The Chrome bug is here http://code.google.com/p/chromium/issues/detail?id=54200
Steps
1. Have an iframe element with a page loaded within.
2. Use script, etc. to place a flash object from the parent page on top of the iframe object.
3. Even if you set the flash object's z-index higher than the iframe's, the flash object will be displayed under the iframe
Here is a site which has this problem. http://mixla.org
The problem appears to affect the Windows port of Chromium only.
I discussed this issue with Thatcher Ulrich from Google who originally wrote this
code for Chromium and John Newlin from Google who rewrote parts of the iframe shim code to fix a layering bug.
We agreed that the proposed fix is the right fix in the short term. Longer term we should look into Firefox's implementation which seems to do the right thing even if there is no iframe shim.
I tested this fix with the test case mentioned in the bug and the test cases on the site maintained by Thatecher Ulrich. They all work fine. The plugin layout test iframe-shims.html also works fine.
Please take a look at the proposed patch. It is relatively low risk as the only consumer of this code is Chromium.
Comment on attachment 68321[details]
Initial patch for this issue
View in context: https://bugs.webkit.org/attachment.cgi?id=68321&action=review> WebKit/chromium/src/WebPluginContainerImpl.cpp:545
> + // it stacks behind the iframe.
it seems like the comment needs to be updated.
> WebKit/chromium/src/WebPluginContainerImpl.cpp:547
> + const RenderObject* pluginRenderObject = pluginZstack[0];
it is not obvious to me why you always check the 0'th elements of pluginZstack and iframeZstack here.
Hi Darin
Thanks for the review. I updated the earlier comment and added a note indicating
why we check the 0'th elements of the RenderObject arrays.
Thanks
Ananta
Comment on attachment 68368[details]
Patch with updated comments
R=me, but is it possible to write a layout test for this extending or building upon the layout test that already exists for iframe shims?
Attachment 68829[details] did not pass style-queue:
Failed to run "['WebKitTools/Scripts/check-webkit-style']" exit_code: 1
WebKit/chromium/ChangeLog:5: Line contains tab character. [whitespace/tab] [5]
Total errors found: 1 in 3 files
If any of these errors are false positives, please file a bug against check-webkit-style.
Comment on attachment 68834[details]
Hopefully the last of the formatting fix.
Rejecting patch 68834 from commit-queue.
Failed to run "['./WebKitTools/Scripts/webkit-patch', '--status-host=queues.webkit.org', 'build-and-test', '--no-clean', '--no-update', '--test', '--quiet', '--non-interactive']" exit_code: 2
Last 500 characters of output:
r....ok
All tests successful.
Files=14, Tests=304, 1 wallclock secs ( 0.72 cusr + 0.16 csys = 0.88 CPU)
Running build-dumprendertree
Compiling Java tests
make: Nothing to be done for `default'.
Running tests from /Projects/CommitQueue/LayoutTests
Testing 21378 test cases.
plugins/iframe-shims.html -> failed
Exiting early after 1 failures. 17854 tests run.
317.92s total testing time
17853 test cases (99%) succeeded
1 test case (<1%) had incorrect layout
31 test cases (<1%) had stderr output
Full output: http://queues.webkit.org/results/4132012
Comment on attachment 69012[details]
Updated patch with the iframe-shims.html added to skipped list for mac platforms.
View in context: https://bugs.webkit.org/attachment.cgi?id=69012&action=review> LayoutTests/platform/mac-leopard/Skipped:106
> +plugins/iframe-shims.html
LayoutTests/platform/mac/Skipped should be sufficent.
> LayoutTests/platform/mac-snowleopard/Skipped:143
> +plugins/iframe-shims.html
LayoutTests/platform/mac/Skipped should be sufficent.
> LayoutTests/platform/mac-tiger/Skipped:212
> +plugins/iframe-shims.html
LayoutTests/platform/mac/Skipped should be sufficent.
> LayoutTests/platform/mac/Skipped:326
> +plugins/iframe-shims.html
What about other platforms like LayoutTests/platform/win/Skipped?
2010-09-21 18:37 PDT, Ananta Iyengar
2010-09-22 07:10 PDT, Ananta Iyengar
2010-09-25 10:20 PDT, Ananta Iyengar
2010-09-25 10:24 PDT, Ananta Iyengar
2010-09-25 10:27 PDT, Ananta Iyengar
2010-09-25 10:28 PDT, Ananta Iyengar
2010-09-25 10:31 PDT, Ananta Iyengar
2010-09-25 10:34 PDT, Ananta Iyengar
2010-09-27 19:19 PDT, Ananta Iyengar
2010-09-28 11:11 PDT, Ananta Iyengar
2010-09-28 12:21 PDT, Ananta Iyengar