Issue #1838 - Part 5: Address follow-up issues to initial flexbox layout for `(column|row)-gap` properties

Notes:
* Bug 1473044 - Make flexbox cross size take row/column gap into account
https://bugzilla.mozilla.org/show_bug.cgi?id=1473044
* Bug 1473047 - Re-resolve row-gap percentages after intrinsic block size calculated
https://bugzilla.mozilla.org/show_bug.cgi?id=1473047
* Bug 1612401 - Prevent absolute-positioned children from contributing gap size to flexbox's inline-size
https://bugzilla.mozilla.org/show_bug.cgi?id=1612401
* Bug 1639627 - Make flex-container percent 'row-gap' values resolve to 0, when they're resolved against an indefinite block-size (essentially reverts Bug 1473047)

1 files changed, 11 insertions, 1 deletions

diff --git a/layout/generic/nsFlexContainerFrame.cpp b/layout/generic/nsFlexContainerFrame.cpp
index 9b5372832c..4429111e46 100644
--- a/layout/generic/nsFlexContainerFrame.cpp
+++ b/layout/generic/nsFlexContainerFrame.cpp
@@ -2330,7 +2330,7 @@ private:
   // XXX this should be uint16_t when we add explicit fallback handling
   uint8_t  mAlignContent;
 
-  nscoord mCrossGapSize = 0;
+  const nscoord mCrossGapSize;
 };
 
 // Utility class for managing our position along the cross axis, *within* a
@@ -4473,6 +4473,11 @@ nsFlexContainerFrame::DoFlexLayout(nsPresContext*           aPresContext,
     // Now that we've finished with this line's items, size the line itself:
     line->ComputeCrossSizeAndBaseline(aAxisTracker);
     sumLineCrossSizes += line->GetLineCrossSize();
+
+    // Add the cross axis gap space if this is not the last line
+    if (line->getNext()) {
+      sumLineCrossSizes += aCrossGapSize;
+    }
   }
 
   bool isCrossSizeDefinite;
@@ -4934,6 +4939,11 @@ nsFlexContainerFrame::GetIntrinsicISize(nsRenderingContext* aRenderingContext,
   bool onFirstChild = true;
 
   for (nsIFrame* childFrame : mFrames) {
+    // Skip out-of-flow children because they don't participate in flex layout.
+    if (childFrame->GetType() == nsGkAtoms::placeholderFrame) {
+      continue;
+    }
+
     nscoord childISize = nsLayoutUtils::IntrinsicForContainer(
         aRenderingContext, childFrame, aType);
     // * For a row-oriented single-line flex container, the intrinsic