225381 2021-05-04 21:41:09 -0700 DisplayList::Recorder::ContextState::wasUsedForDrawing is unused and can probably be removed 2021-05-05 16:07:14 -0700 1 1 1 Unclassified WebKit Layout and Rendering WebKit Local Build Unspecified Unspecified RESOLVED FIXED https://bugs.webkit.org/show_bug.cgi?id=208659 https://bugs.webkit.org/show_bug.cgi?id=152816 InRadar P2 Normal --- 1 heycam heycam bfulgham sabouhallawa simon.fraser webkit-bug-importer zalan oldest_to_newest 1756797 0 heycam 2021-05-04 21:41:09 -0700 . 1756800 1 427732 heycam 2021-05-04 21:47:48 -0700 Created attachment 427732 Patch 1757006 2 sabouhallawa 2021-05-05 11:36:07 -0700 This member was introduced in r194708 and its use was removed in r257958. Its original goal was to remove save/restore pair from DisplayList if no drawing happens in between. For example a sequence like this can be completed removed from the DisplayList since its replaying back has no effect: context.save(); context.setFillColor(Color::green); context.restore(); But the problem was in the Canvas case where calling the save() and restore() may happen in different frames. Recording a restore item may try to remove the last save item although the matching save item was pushed to the context of the ImageBuffer many frames earlier. 1757136 3 heycam 2021-05-05 15:36:22 -0700 Thanks for the background. I did do a `grep -G wasUsedForDrawing` to check, but that didn't bring up the r257958 commit (since that removed a use of the `stateUsedForDrawing` local variable). 1757137 4 heycam 2021-05-05 15:36:49 -0700 (In reply to Cameron McCormack (:heycam) from comment #3) > Thanks for the background. I did do a `grep -G wasUsedForDrawing` *git grep -G wasUsedForDrawing 1757149 5 ews-feeder 2021-05-05 16:06:28 -0700 Committed r277050 (237360@main): <https://commits.webkit.org/237360@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 427732. 1757150 6 webkit-bug-importer 2021-05-05 16:07:14 -0700 <rdar://problem/77580546> 427732 2021-05-04 21:47:48 -0700 2021-05-05 16:06:29 -0700 Patch bug-225381-20210505144746.patch text/plain 2676 heycam U3VidmVyc2lvbiBSZXZpc2lvbjogMjc2OTg0CmRpZmYgLS1naXQgYS9Tb3VyY2UvV2ViQ29yZS9D aGFuZ2VMb2cgYi9Tb3VyY2UvV2ViQ29yZS9DaGFuZ2VMb2cKaW5kZXggZmNlY2IwMDU1YzlhMjQ3 MTZiZjcyZjE4M2ZkMDZmZjM0NmExZDE3ZC4uZjY1MGVlOTA1YzFhMWNmMGU5MWRmNzNkZjMzYmVm ZmE4YmUzZGI3ZSAxMDA2NDQKLS0tIGEvU291cmNlL1dlYkNvcmUvQ2hhbmdlTG9nCisrKyBiL1Nv dXJjZS9XZWJDb3JlL0NoYW5nZUxvZwpAQCAtMSwzICsxLDE1IEBACisyMDIxLTA1LTA0ICBDYW1l cm9uIE1jQ29ybWFjayAgPGhleWNhbUBhcHBsZS5jb20+CisKKyAgICAgICAgUmVtb3ZlIHVudXNl ZCBEaXNwbGF5TGlzdDo6UmVjb3JkZXI6OkNvbnRleHRTdGF0ZTo6d2FzVXNlZEZvckRyYXdpbmcK KyAgICAgICAgaHR0cHM6Ly9idWdzLndlYmtpdC5vcmcvc2hvd19idWcuY2dpP2lkPTIyNTM4MQor CisgICAgICAgIFJldmlld2VkIGJ5IE5PQk9EWSAoT09QUyEpLgorCisgICAgICAgICogcGxhdGZv cm0vZ3JhcGhpY3MvZGlzcGxheWxpc3RzL0Rpc3BsYXlMaXN0UmVjb3JkZXIuY3BwOgorICAgICAg ICAoV2ViQ29yZTo6RGlzcGxheUxpc3Q6OlJlY29yZGVyOjpjYW5BcHBlbmRJdGVtT2ZUeXBlKToK KyAgICAgICAgKFdlYkNvcmU6OkRpc3BsYXlMaXN0OjpSZWNvcmRlcjo6cmVzdG9yZSk6CisgICAg ICAgICogcGxhdGZvcm0vZ3JhcGhpY3MvZGlzcGxheWxpc3RzL0Rpc3BsYXlMaXN0UmVjb3JkZXIu aDoKKwogMjAyMS0wNS0wNCAgQ2FtZXJvbiBNY0Nvcm1hY2sgIDxoZXljYW1AYXBwbGUuY29tPgog CiAgICAgICAgIEZpeCBjb3B5IHBhc3RlIGVycm9yIGluIFJlY29yZGVyOjpjYW5BcHBlbmRJdGVt T2ZUeXBlLgpkaWZmIC0tZ2l0IGEvU291cmNlL1dlYkNvcmUvcGxhdGZvcm0vZ3JhcGhpY3MvZGlz cGxheWxpc3RzL0Rpc3BsYXlMaXN0UmVjb3JkZXIuY3BwIGIvU291cmNlL1dlYkNvcmUvcGxhdGZv cm0vZ3JhcGhpY3MvZGlzcGxheWxpc3RzL0Rpc3BsYXlMaXN0UmVjb3JkZXIuY3BwCmluZGV4IGRi MGFjMmYyNzczOWVlY2Y5YWQwODMwYzc1YjYyODcyMGUyODViNDkuLjU3ODczMTM5MzQ1MDFlMzJh NTFiYTJjZjVhNjQ1NTQwMGQ3YTcyNWYgMTAwNjQ0Ci0tLSBhL1NvdXJjZS9XZWJDb3JlL3BsYXRm b3JtL2dyYXBoaWNzL2Rpc3BsYXlsaXN0cy9EaXNwbGF5TGlzdFJlY29yZGVyLmNwcAorKysgYi9T b3VyY2UvV2ViQ29yZS9wbGF0Zm9ybS9ncmFwaGljcy9kaXNwbGF5bGlzdHMvRGlzcGxheUxpc3RS ZWNvcmRlci5jcHAKQEAgLTEzOSw3ICsxMzksNiBAQCBib29sIFJlY29yZGVyOjpjYW5BcHBlbmRJ dGVtT2ZUeXBlKEl0ZW1UeXBlIHR5cGUpCiAgICAgICAgICAgICBzdGF0ZUNoYW5nZXMubV9jaGFu Z2VGbGFncyA9IHsgfTsKICAgICAgICAgICAgIGN1cnJlbnRTdGF0ZSgpLmxhc3REcmF3aW5nU3Rh dGUgPSBzdGF0ZUNoYW5nZXMubV9zdGF0ZTsKICAgICAgICAgfQotICAgICAgICBjdXJyZW50U3Rh dGUoKS53YXNVc2VkRm9yRHJhd2luZyA9IHRydWU7CiAgICAgfQogCiAgICAgcmV0dXJuIHRydWU7 CkBAIC0yMjcsMTIgKzIyNiw3IEBAIHZvaWQgUmVjb3JkZXI6OnJlc3RvcmUoKQogICAgIGlmICgh bV9zdGF0ZVN0YWNrLnNpemUoKSkKICAgICAgICAgcmV0dXJuOwogCi0gICAgYm9vbCBzdGF0ZVVz ZWRGb3JEcmF3aW5nID0gY3VycmVudFN0YXRlKCkud2FzVXNlZEZvckRyYXdpbmc7Ci0KICAgICBt X3N0YXRlU3RhY2sucmVtb3ZlTGFzdCgpOwotICAgIC8vIEhhdmUgdG8gYXZvaWQgZWxpZGluZyBu ZXN0ZWQgU2F2ZS9SZXN0b3JlIHdoZW4gYSBkZXNjZW5kYW50IHN0YXRlIGNvbnRhaW5zIGRyYXdp bmcgaXRlbXMuCi0gICAgY3VycmVudFN0YXRlKCkud2FzVXNlZEZvckRyYXdpbmcgfD0gc3RhdGVV c2VkRm9yRHJhd2luZzsKLQogICAgIGFwcGVuZDxSZXN0b3JlPigpOwogfQogCmRpZmYgLS1naXQg YS9Tb3VyY2UvV2ViQ29yZS9wbGF0Zm9ybS9ncmFwaGljcy9kaXNwbGF5bGlzdHMvRGlzcGxheUxp c3RSZWNvcmRlci5oIGIvU291cmNlL1dlYkNvcmUvcGxhdGZvcm0vZ3JhcGhpY3MvZGlzcGxheWxp c3RzL0Rpc3BsYXlMaXN0UmVjb3JkZXIuaAppbmRleCA3NTJmYjUxNGJjMWI5OWYwOTdlOTViZmIx ODFiMjIxY2Y3OGQxZDdhLi44NmRjZDFmZGFiNWM0OGFiYjlhNWI3YWNkM2UyMmI0ZmZmNWM5ZDlk IDEwMDY0NAotLS0gYS9Tb3VyY2UvV2ViQ29yZS9wbGF0Zm9ybS9ncmFwaGljcy9kaXNwbGF5bGlz dHMvRGlzcGxheUxpc3RSZWNvcmRlci5oCisrKyBiL1NvdXJjZS9XZWJDb3JlL3BsYXRmb3JtL2dy YXBoaWNzL2Rpc3BsYXlsaXN0cy9EaXNwbGF5TGlzdFJlY29yZGVyLmgKQEAgLTE5Miw3ICsxOTIs NiBAQCBwcml2YXRlOgogICAgICAgICBGbG9hdFJlY3QgY2xpcEJvdW5kczsKICAgICAgICAgR3Jh cGhpY3NDb250ZXh0U3RhdGVDaGFuZ2Ugc3RhdGVDaGFuZ2U7CiAgICAgICAgIEdyYXBoaWNzQ29u dGV4dFN0YXRlIGxhc3REcmF3aW5nU3RhdGU7Ci0gICAgICAgIGJvb2wgd2FzVXNlZEZvckRyYXdp bmcgeyBmYWxzZSB9OwogICAgICAgICAKICAgICAgICAgQ29udGV4dFN0YXRlKGNvbnN0IEdyYXBo aWNzQ29udGV4dFN0YXRlJiBzdGF0ZSwgY29uc3QgQWZmaW5lVHJhbnNmb3JtJiB0cmFuc2Zvcm0s IGNvbnN0IEZsb2F0UmVjdCYgY2xpcCkKICAgICAgICAgICAgIDogY3RtKHRyYW5zZm9ybSkK