Bug 1593170. Check if contentRootElement is a dead wrapper before using it. r=mattwoodrow,dbaron With the fission changes everything is more async, meaning some tests can run longer. Some crashtests navigate to a new location meaning the original root element we have a variable for is no longer around, and chrome isn't allowed to keep content nodes alive, so we are left holding a dead wrapper that throws if we try to access anything on it. So we check if contentRootElement has become a dead wrapper (and null it out) any time we try to access it and it could have become dead. Generally the existing code already handled a null contentRootElement. Differential Revision: https://phabricator.services.mozilla.com/D52829

Bug 1593170. Check if contentRootElement is a dead wrapper before using it. r=mattwoodrow,dbaron With the fission changes everything is more async, meaning some tests can run longer. Some crashtests navigate to a new location meaning the original root element we have a variable for is no longer around, and chrome isn't allowed to keep content nodes alive, so we are left holding a dead wrapper that throws if we try to access anything on it. So we check if contentRootElement has become a dead wrapper (and null it out) any time we try to access it and it could have become dead. Generally the existing code already handled a null contentRootElement. Differential Revision: https://phabricator.services.mozilla.com/D52829

Bug 1584040 - Allow assertions in outline-in-frameset.xhtml crashtest; r=dbaron Accept assertions to avoid intermittent test failures due to assertion count mismatches. Differential Revision: https://phabricator.services.mozilla.com/D50660

Bug 1588760 - Move css-lists reftests into WPT r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D49278

Bug 1590185 Part 2 - Support paged mode layout in layout debugger. r=dbaron This patch adds a menu item in "Toggle" -> "Paged Mode". If the item is toggled, after finishing loading the document, the document will be forced into paged mode. The print settings in `nsLayoutDebuggingTools::SetPagedMode()` are similar to `setupPrintMode()` in reftest-content.js. Remove the hack in nsDocumentViewer::InitInternal() because we don't want to set a new document when mIsPageMode = false. Differential Revision: https://phabricator.services.mozilla.com/D49993

Bug 584141 Added WBR frame class implementing nsFrame and overriding thepeekOffset* methods. r=dbaron,Ehsan The wbr element represents a line break opportunity. Before the change double clicking on a text that contains a wbr element did not select the whole sentence. After the change, the presence of a wbr element in the selection does not affect the selection functionality. Differential Revision: https://phabricator.services.mozilla.com/D47558

Bug 1584859 - Make smooth scrolling conditional on reduced motion settings. r=dbaron We could put this change itself behind a pref too, if we considered that worth it. But probably not so. Differential Revision: https://phabricator.services.mozilla.com/D48010

Bug 1426010 - Ship column-span. r=dbaron Enable layout.css.column-span.enabled in all channels. Differential Revision: https://phabricator.services.mozilla.com/D47352

Bug 1579565 Part 2 - Skip block-end side if the frame has a column-span sibling. r=dbaron Also, clean up the wording and variable names when aReflowInput is used. Differential Revision: https://phabricator.services.mozilla.com/D47676

Bug 1579565 Part 1 - Skip applying the child block's block-end margin when placing it if it has a later sibling across column-span split. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D47675

Bug 1547160 - Update comments for expected column-span test failures. r=dbaron multicol-span-all-margin-bottom-001.xht and multicol-span-none-001.xht have been patched upstream. They should pass after we import from wpt. DONTBUILD because this is a comment-only change. Differential Revision: https://phabricator.services.mozilla.com/D47340

Bug 1575054 - Disable column balancing for nested multicol containers of depth more than two. r=dbaron That is, for the multicol container of depth two and more, we lay them out by using "column-fill:auto" and "column-count:1". I've check bug 725376 comment 9 for the previous approaches. Thanks to bug 1555818, this solution is feasible because the fragmentation with "column-fill:auto" is now possible. Differential Revision: https://phabricator.services.mozilla.com/D47011

Bug 1575054 - Disable column balancing for nested multicol containers of depth more than two. r=dbaron That is, for the multicol container of depth two and more, we lay them out by using "column-fill:auto" and "column-count:1". I've check bug 725376 comment 9 for the previous approaches. Thanks to bug 1555818, this solution is feasible because the fragmentation with "column-fill:auto" is now possible. Differential Revision: https://phabricator.services.mozilla.com/D47011

Bug 1583639 Part 4 - Stop creating more columns in column-fill:auto mode if there's still block-size left in multicol container. r=dbaron This patch makes fragmentation in "column-fill:auto" mode possible. Note that we only bail out of creating more column contents when "column-fill:auto" mode is set from the styles, i.e. when mForceAuto is false. That is because when mForceAuto is true, we usually in the case where we have gave up balancing, and we really want to create overflow columns. Note: without `!aConfig.mForceAuto` check, 673770.html can generated assertions, and the frame tree contains dangling Overflow-lines and ExcessOverflowContainersList. Differential Revision: https://phabricator.services.mozilla.com/D47005

Bug 1583639 Part 3 - Keep the optimal used numColumns in column-fill:auto mode without resetting it to INT32_MAX. r=dbaron mUsedColCount is used in balancing mode to check whether we have created the maximum number of columns when the content cannot fit. Similarly, mUsedColCount can also be useful in "column-fill:auto" mode to improve the fragmentation story in the next patch. This patch doesn't change the behavior (yet). Differential Revision: https://phabricator.services.mozilla.com/D47004

Bug 1583639 Part 2 - Rename mBalanceColCount to mUsedColCount in nsColumnSetFrame::ReflowConfig. r=dbaron In next patch, this variable won't be set to INT32_MAX in "column-fill:auto" mode, and it will be used in Part 4. Hence the rename. Differential Revision: https://phabricator.services.mozilla.com/D47003

Bug 1583639 Part 1 - De-indent an else-block inside the while-loop in nsColumnSetFrame::ReflowChild. r=dbaron The associated if-block has a "break" statement at the end of the scope to break the while-loop, making the else-block redundant. Differential Revision: https://phabricator.services.mozilla.com/D47002

Bug 1482778 - Include captions within table outlines. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D45802

Bug 1575016 - Update a comment that describes minimum 1px block-size for column-content blocks. r=dbaron Fragmentation spec already has a paragraph describing this behavior. DONTBUILD because this is a comment only change. Differential Revision: https://phabricator.services.mozilla.com/D46691

Bug 1575964 Part 2 - Fix RTL column positions when column-span is enabled. r=dbaron Since column-contents' positions are moved, we need to fix ColumnSet's overflow areas as well. Differential Revision: https://phabricator.services.mozilla.com/D44279

Bug 1575964 Part 1 - Separate a fixup logic which is redundant if column-span is enabled. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D44278

Bug 1523582 Part 5 - Update test expectations. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D44029

Bug 1523582 Part 4 - Support comment at the end of line in failures.list, and regenerate reftest.list. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D44028

Bug 1523582 Part 3 - Adjust GetLogicalSkipSides() to check non-fluid continuations. r=dbaron Frames split by column-span are linked together by non-fluid continuations. We want GetLogicalSkipSides() to recognize that. The documentation in nsIFrame::GetLogicalSkipSides() already uses *continuation* rather than *in-flow*, so no need to adjust the wording. However, after patching GetLogicalSkipSides(), the first column-content after a column-span split starts to skip the block-start side because it has a previous continuation. We want the content in the first column to consider applying its block-start margin. Hence the modification in BlockReflowInput's constructor. (Note that the first column-content is always a block-start margin-root, which is fixed in the previous part.) This is necessary to avoid breaking testing/web-platform/tests/css/css-multicol/multicol-span-all-margin-bottom-001.xht In multicol-span-all-children-height-006.html, add "margin-top: 1em;" to the container to expose the bug if we still check GetPrevInFlow() rather than GetPrevContinuation() when computing applyBStartMargin in nsBlockFrame::ReflowBlockFrame(). Differential Revision: https://phabricator.services.mozilla.com/D43905

Bug 1523582 Part 2 - Make -moz-column-content a BFC when column-span is enabled. r=dbaron Based on CSS working group's resolution in https://github.com/w3c/csswg-drafts/issues/2582#issuecomment-402619872, column-boxes are BFC. Add NS_BLOCK_FORMATTING_CONTEXT_STATE_BITS to -moz-column-content, but only for the new multicol layout. Differential Revision: https://phabricator.services.mozilla.com/D43904

Bug 1523582 Part 1 - Use NOISY_BLOCK_DIR_MARGINS to control log print in nsBlockReflowContext. r=dbaron nsBlockDebugFlags.h defines NOISY_BLOCK_DIR_MARGINS, which is used in nsBlockFrame. Include it in nsBlockReflowContext.cpp so that when NOISY_BLOCK_DIR_MARGINS is defined, the log is printed in nsBlockReflowContext.cpp as well. Remove unused NOISY_MAX_ELEMENT_SIZE and REALLY_NOISY_MAX_ELEMENT_SIZE. Differential Revision: https://phabricator.services.mozilla.com/D43903

Bug 1577072 followup: Use an even larger line-height in our "bigger-than-one" text-input line-height reftest, to accommodate bigger widgets on Debian. r=dbaron Previous commit on this bug bumped up the test from a line-height of 1.5 to 1.8, but that's still not taller than the default widget height on Debian. But 2.5 does seem to be sufficiently tall to produce a size difference. Differential Revision: https://phabricator.services.mozilla.com/D44719

Bug 1577390 - Wait a bit before loading document in Layout Debugger when profiling. r=dbaron That gives the profiler a chance to attach to a newly created content process. There's no API for waiting for the profiler to be ready in a just-created process, unfortunately. Differential Revision: https://phabricator.services.mozilla.com/D43898

Bug 1577072: Use a slightly larger line-height in our "bigger-than-one" text-input line-height reftest, to accommodate bigger widgets on Debian. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D43787

Bug 1573329 - Add web-platform reftests for multicol breaking. r=dbaron These tests are fixed by bug 1575106, Differential Revision: https://phabricator.services.mozilla.com/D43676

Bug 1575106 Part 4 - Add reftests, crashtests, and adjust test expectations. r=dbaron 1346454-1.html and 1346454-2.html are moved to keep the list sorted. Differential Revision: https://phabricator.services.mozilla.com/D43129

Bug 1575106 Part 3 - Use unconstrained block-size to measure last column, and revise condition to create overflow columns. r=dbaron This patch changes behavior only if column-span is enabled. It fixes a lot of fuzzing test cases which will be added in the next part. It changes the column balancing behavior in the following ways. 1) By using unconstrained block-size to measure the last column in the first balancing iteration, we can guarantee that mKnownFeasibleBSize has the correct feasible block-size. 2) Always reflow one more time if the content cannot fit in the available content block-size. Due to 1), the content (last column) always returns fully complete in the first balancing iteration even if it's in an inner column with a constrained available block-size. We need to reflow again to get the correct *incomplete* reflow status so that the outer column can create next-in-flows for the inner column. 3) ColumnSet gives up balancing only when ColumnSetWrapper is running out of block-size. When a ColumnSetWrapper has constrained block-size, i.e. it's in a fragmentation context like pages or nested columns, we prioritize fragmenting ColumnSetWrapper over creating overflow columns within the nsColumnSet. Differential Revision: https://phabricator.services.mozilla.com/D43128

Bug 1575106 Part 2 - Rename blockReflowInput to childReflowInput in nsBlockFrame::ReflowBlockFrame(). r=dbaron Every time I read the code, the name `blockReflowInput` makes me think the variable is an instance of `BlockReflowInput`, but it is not. Differential Revision: https://phabricator.services.mozilla.com/D43127

Bug 1575106 Part 1 - Use a variable to indicate ColumnSet is measuring the feasible block-size. r=dbaron That is when ColumnSet gives its last ::moz-column-content unbounded available block-size in the very first balancing iteration. Note that the last column's available block-size isn't really *unbounded* yet, but we'll make it happen in the next part. Differential Revision: https://phabricator.services.mozilla.com/D43126

Bug 1569077 - Part 3: Add --capture-profile argument to the layout debugger. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D39469

Bug 1569077 - Part 2: Add --autoclose argument to the layout debugger. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D39468

Bug 1569077 - Part 1: Refactor layout debugger command line handling. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D39467

Bug 1568001 - Add crashtests fixed by bug 1420528. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D42931

Bug 1575305 Part 4 - Improve column set log. r=dbaron 1. Add `this` to the log so that it's easier to debug a nested column balancing 2. Print the struct fields the same as their names. Differential Revision: https://phabricator.services.mozilla.com/D42711

Bug 1575305 Part 3 - Initialize colBSize with available block-size when column-span is enabled. r=dbaron nsBlockFrame already prepares the available block-size for ColumnSetFrame with ColumnSetWrapper's block-size and max-block-size applied. (ColumnSet's computed block-size and max block-size is always unconstrained when column-span is enabled.) Differential Revision: https://phabricator.services.mozilla.com/D42710

Bug 1575305 Part 2 - Remove the unused border-padding variable in nsBlockFrame::FindBestBalanceBSize(). r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D42709

Bug 1575305 Part 1 - Remove an unneeded condition used for ::-moz-column-content. r=dbaron Before bug 1411422, a ::-moz-column-content has height:100%, so it could go into this path if ColumnSet's available block-size is unconstrained. However, after bug 1411422, height:100% was removed for ::-moz-column-content. That is, its computed block-size is unconstrained, so it can't go into this path. This applies regardless of whether column-span is enabled or not. Differential Revision: https://phabricator.services.mozilla.com/D42708

Bug 1570556 - Remove call to pango_fc_font_map_shutdown, which was moved out of public headers in Pango 1.44. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D42127

Bug 1569701 Part 2 - Use ColumnSetWrapper's effective computed content block-size to impose constraint for ColumnSet. r=dbaron Run broken-column-rule-1.html with column-span enabled because it was regressed by Bug 1548100 Part 2, but fixed by this patch. Differential Revision: https://phabricator.services.mozilla.com/D41907

Bug 1569701 Part 1 - Make BlockReflowInput::mConsumedBSize a constant, and delete it assessor method. r=dbaron We always pass consumed block-size into BlockReflowInput's constructor in nsBlockFrame::Reflow(). By making mConsumedBSize a constant, its assessor method becomes redundant. Update the documentation to reflect the reality that ConsumedBSize() accumulates content block-size from all previous *continuations*, which was done in Bug 1506293 Part 2. Differential Revision: https://phabricator.services.mozilla.com/D41906

Bug 1569701 Part 0 - Use nscoord instead of int for contentBEnd in nsColumnSetFrame::ReflowChildren(). r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D41905

Bug 1573761 - Add a web-platform reftest multicol-breaking-nobackground-004.html r=dbaron For a better symmetry between the multicol-breaking tests and their no background variants, this patch adds a nobackground test for multicol-breaking-004.html. This tests the same things as multicol-breaking-004.html, but with two things removed: outer column's blue column-rules and inner columns' background. Differential Revision: https://phabricator.services.mozilla.com/D41903

Bug 1571849 - In ColumnSetFrame, use mParentReflowInput to get the ColumnSetWrapperFrame's reflow input. r=dbaron In ColumnSetFrame's reflow methods, mCBReflowInput is equal to mParentReflowInput in most of the cases. However, a multicol <button> has the HTMLButtonControl as the outermost frame, where ColumnSetWrapper is its -moz-button-content anonymous child. In this case, mCBReflowInput is HTMLButtonControl's reflow input. To get the correct computedBSize of ColumnSetWrapper, we need to use mParentReflowInput. Differential Revision: https://phabricator.services.mozilla.com/D41497

Bug 1572912 - Enable column-span preference to fix existing test failures. r=dbaron Differential Revision: https://phabricator.services.mozilla.com/D41496

Bug 1569252 Part 2 - Let mHasColumnSpanSiblings propagate to all the continuations. r=dbaron We want mHasColumnSpanSiblings to propagate to all the continuations (both fixed ones or fluid ones) in nsFrame::Init() so that we don't need to traverse all the way to FirstInFlow() for the bit in nsBlockFrame::ComputeFinalBSize(). For the last ColumnSet or the last non-column-span wrapper, we'll need to unset the bit for them manually after constructing them. Differential Revision: https://phabricator.services.mozilla.com/D40761