Bug 1733952 - When computing inline intrinsic sizes, resolve with a 0…

… percentage basis rather than just resolving to zero if there's a percentage. r=jfkthame This matches other browsers, the spec (https://drafts.csswg.org/css-sizing/#cyclic-percentage-contribution): For the min size properties, as well as for margins and paddings (and gutters), a cyclic percentage is resolved against zero for determining intrinsic size contributions. And also what we do in SizeComputationInput::Compute{Margin,Padding}: https://searchfox.org/mozilla-central/rev/75e9d727ce5ba2c14653cf8fb0f1367f085271b7/layout/generic/ReflowInput.cpp#2811-2832 https://searchfox.org/mozilla-central/rev/75e9d727ce5ba2c14653cf8fb0f1367f085271b7/layout/generic/ReflowInput.cpp#2861-2868 This fixes a compat issue with the menu alignment in lume.io: webcompat/web-bugs#88484 (comment) It's also simpler. Differential Revision: https://phabricator.services.mozilla.com/D127441
jamienicol · Oct 4, 2021 · 438aa90 · 438aa90
1 parent 622ae51
commit 438aa90
Show file tree

Hide file tree

Showing 3 changed files with 43 additions and 26 deletions.
diff --git a/layout/generic/nsContainerFrameInlines.h b/layout/generic/nsContainerFrameInlines.h
@@ -9,32 +9,14 @@
 
 #include "nsContainerFrame.h"
 
-namespace mozilla {
-namespace detail {
-
-static nscoord GetCoord(const LengthPercentage& aCoord, nscoord aIfNotCoord) {
-  if (aCoord.ConvertsToLength()) {
-    return aCoord.ToLength();
-  }
-  return aIfNotCoord;
-}
-
-static nscoord GetCoord(const LengthPercentageOrAuto& aCoord,
-                        nscoord aIfNotCoord) {
-  if (aCoord.IsAuto()) {
-    return aIfNotCoord;
-  }
-  return GetCoord(aCoord.AsLengthPercentage(), aIfNotCoord);
-}
-
-}  // namespace detail
-}  // namespace mozilla
-
 template <typename ISizeData, typename F>
 void nsContainerFrame::DoInlineIntrinsicISize(ISizeData* aData,
                                               F& aHandleChildren) {
   using namespace mozilla;
-  using mozilla::detail::GetCoord;
+
+  auto GetMargin = [](const LengthPercentageOrAuto& aCoord) -> nscoord {
+    return aCoord.IsAuto() ? 0 : aCoord.AsLengthPercentage().Resolve(0);
+  };
 
   if (GetPrevInFlow()) return;  // Already added.
 
@@ -61,9 +43,9 @@ void nsContainerFrame::DoInlineIntrinsicISize(ISizeData* aData,
   if (!GetPrevContinuation() || MOZ_UNLIKELY(!sliceBreak)) {
     nscoord startPBM =
         // clamp negative calc() to 0
-        std::max(GetCoord(stylePadding->mPadding.Get(startSide), 0), 0) +
+        std::max(stylePadding->mPadding.Get(startSide).Resolve(0), 0) +
         styleBorder->GetComputedBorderWidth(startSide) +
-        GetCoord(styleMargin->mMargin.Get(startSide), 0);
+        GetMargin(styleMargin->mMargin.Get(startSide));
     if (MOZ_LIKELY(sliceBreak)) {
       aData->mCurrentLine += startPBM;
     } else {
@@ -73,9 +55,9 @@ void nsContainerFrame::DoInlineIntrinsicISize(ISizeData* aData,
 
   nscoord endPBM =
       // clamp negative calc() to 0
-      std::max(GetCoord(stylePadding->mPadding.Get(endSide), 0), 0) +
+      std::max(stylePadding->mPadding.Get(endSide).Resolve(0), 0) +
       styleBorder->GetComputedBorderWidth(endSide) +
-      GetCoord(styleMargin->mMargin.Get(endSide), 0);
+      GetMargin(styleMargin->mMargin.Get(endSide));
   if (MOZ_UNLIKELY(!sliceBreak)) {
     clonePBM += endPBM;
     aData->mCurrentLine += clonePBM;

diff --git a/testing/web-platform/tests/css/css-sizing/inline-intrinsic-size-calc-ref.html b/testing/web-platform/tests/css/css-sizing/inline-intrinsic-size-calc-ref.html
@@ -0,0 +1,15 @@
+<!doctype html>
+<title>Calc gets resolved with 0 percent basis for intrinsic size computation</title>
+<style>
+  div {
+    background-color: green;
+    width: max-content;
+  }
+  span {
+    margin-left: 30px;
+    padding-left: 50px;
+  }
+</style>
+<div>
+  <span>ABCD</span>
+</div>
diff --git a/testing/web-platform/tests/css/css-sizing/inline-intrinsic-size-calc.html b/testing/web-platform/tests/css/css-sizing/inline-intrinsic-size-calc.html
@@ -0,0 +1,20 @@
+<!doctype html>
+<title>Calc gets resolved with 0 percent basis for intrinsic size computation</title>
+<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
+<link rel="author" title="Mozilla" href="https://mozilla.org">
+<link rel="match" href="inline-intrinsic-size-calc-ref.html">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1733952">
+<link rel="help" href="https://drafts.csswg.org/css-sizing/#cyclic-percentage-contribution">
+<style>
+  div {
+    background-color: green;
+    width: max-content;
+  }
+  span {
+    margin-left: calc(0% + 30px);
+    padding-left: calc(0% + 50px);
+  }
+</style>
+<div>
+  <span>ABCD</span>
+</div>