It is mostly an implementation detail of TextDecorationPainter.
Created attachment 288910 [details] patch
Comment on attachment 288910 [details] patch View in context: https://bugs.webkit.org/attachment.cgi?id=288910&action=review > Source/WebCore/rendering/TextDecorationPainter.cpp:398 > + if (!requestedDecorations) Would prefer a blank line above.
Comment on attachment 288910 [details] patch Attachment 288910 [details] did not pass mac-debug-ews (mac): Output: http://webkit-queues.webkit.org/results/2076236 New failing tests: fast/css/text-decorations-on-first-line-and-containing-block.html
Created attachment 288914 [details] Archive of layout-test-results from ews117 for mac-yosemite The attached test failures were seen while running run-webkit-tests on the mac-debug-ews. Bot: ews117 Port: mac-yosemite Platform: Mac OS X 10.10.5
Comment on attachment 288910 [details] patch Attachment 288910 [details] did not pass mac-ews (mac): Output: http://webkit-queues.webkit.org/results/2076294 New failing tests: fast/css/text-decorations-on-first-line-and-containing-block.html
Created attachment 288917 [details] Archive of layout-test-results from ews102 for mac-yosemite The attached test failures were seen while running run-webkit-tests on the mac-ews. Bot: ews102 Port: mac-yosemite Platform: Mac OS X 10.10.5
Comment on attachment 288910 [details] patch Attachment 288910 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.webkit.org/results/2076310 New failing tests: fast/css/text-decorations-on-first-line-and-containing-block.html
Created attachment 288920 [details] Archive of layout-test-results from ews105 for mac-yosemite-wk2 The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews. Bot: ews105 Port: mac-yosemite-wk2 Platform: Mac OS X 10.10.5
Comment on attachment 288910 [details] patch Attachment 288910 [details] did not pass ios-sim-ews (ios-simulator-wk2): Output: http://webkit-queues.webkit.org/results/2076311 New failing tests: fast/css/text-decorations-on-first-line-and-containing-block.html
Created attachment 288921 [details] Archive of layout-test-results from ews123 for ios-simulator-elcapitan-wk2 The attached test failures were seen while running run-webkit-tests on the ios-sim-ews. Bot: ews123 Port: ios-simulator-elcapitan-wk2 Platform: Mac OS X 10.11.6
Created attachment 288970 [details] patch
https://trac.webkit.org/r205985