Merge commit 'eb77e289bbe056b58051db0fa868e95da803aa0a' into Basilisk-release

9 files changed, 158 insertions, 19 deletions

diff --git a/layout/base/nsLayoutUtils.h b/layout/base/nsLayoutUtils.h
index 63253fd10..0a82dbf6a 100644
--- a/layout/base/nsLayoutUtils.h
+++ b/layout/base/nsLayoutUtils.h
@@ -1439,13 +1439,14 @@ public:
   /**
    * This function increases an initial intrinsic size, 'aCurrent', according
    * to the given 'aPercent', such that the size-increase makes up exactly
-   * 'aPercent' percent of the returned value.  If 'aPercent' is less than
-   * or equal to zero the original 'aCurrent' value is returned. If 'aPercent'
-   * is greater than or equal to 1.0 the value nscoord_MAX is returned.
+   * 'aPercent' percent of the returned value.  If 'aPercent' or 'aCurrent' are
+   * less than or equal to zero the original 'aCurrent' value is returned.
+   * If 'aPercent' is greater than or equal to 1.0 the value nscoord_MAX is
+   * returned.
    */
   static nscoord AddPercents(nscoord aCurrent, float aPercent)
   {
-    if (aPercent > 0.0f) {
+    if (aPercent > 0.0f && aCurrent > 0) {
       return MOZ_UNLIKELY(aPercent >= 1.0f) ? nscoord_MAX
         : NSToCoordRound(float(aCurrent) / (1.0f - aPercent));
     }
diff --git a/layout/base/nsPresShell.cpp b/layout/base/nsPresShell.cpp
index 969ebc962..5dfbb8dba 100644
--- a/layout/base/nsPresShell.cpp
+++ b/layout/base/nsPresShell.cpp
@@ -7296,11 +7296,11 @@ PresShell::HandleEvent(nsIFrame* aFrame,
     return NS_OK;
   }
 
-  nsIContent* capturingContent = ((aEvent->mClass == ePointerEventClass ||
-                                   aEvent->mClass == eWheelEventClass ||
-                                   aEvent->HasMouseEventMessage())
-                                 ? GetCapturingContent()
-                                 : nullptr);
+  nsCOMPtr<nsIContent> capturingContent = ((aEvent->mClass == ePointerEventClass ||
+                                            aEvent->mClass == eWheelEventClass ||
+                                            aEvent->HasMouseEventMessage())
+                                          ? GetCapturingContent()
+                                          : nullptr);
 
   nsCOMPtr<nsIDocument> retargetEventDoc;
   if (!aDontRetargetEvents) {
diff --git a/layout/generic/nsAbsoluteContainingBlock.cpp b/layout/generic/nsAbsoluteContainingBlock.cpp
index 7c48aae92..e3c847d01 100644
--- a/layout/generic/nsAbsoluteContainingBlock.cpp
+++ b/layout/generic/nsAbsoluteContainingBlock.cpp
@@ -409,14 +409,30 @@ OffsetToAlignedStaticPos(const ReflowInput& aKidReflowInput,
                         ? GetOrthogonalAxis(aAbsPosCBAxis)
                         : aAbsPosCBAxis);
 
+  const bool placeholderContainerIsContainingBlock =
+    aPlaceholderContainer == aKidReflowInput.mCBReflowInput->mFrame;
+
   nsIAtom* parentType = aPlaceholderContainer->GetType();
   LogicalSize alignAreaSize(pcWM);
   if (parentType == nsGkAtoms::flexContainerFrame) {
-    // The alignment container is the flex container's content box:
-    alignAreaSize = aPlaceholderContainer->GetLogicalSize(pcWM);
-    LogicalMargin pcBorderPadding =
-      aPlaceholderContainer->GetLogicalUsedBorderAndPadding(pcWM);
-    alignAreaSize -= pcBorderPadding.Size(pcWM);
+    // We store the frame rect in FinishAndStoreOverflow, which runs _after_
+    // reflowing the absolute frames, so handle the special case of the frame
+    // being the actual containing block here, by getting the size from
+    // aAbsPosCBSize.
+    //
+    // The alignment container is the flex container's content box.
+    if (placeholderContainerIsContainingBlock) {
+      alignAreaSize = aAbsPosCBSize.ConvertTo(pcWM, aAbsPosCBWM);
+      // aAbsPosCBSize is the padding-box, so substract the padding to get the
+      // content box.
+      alignAreaSize -=
+        aPlaceholderContainer->GetLogicalUsedPadding(pcWM).Size(pcWM);
+    } else {
+      alignAreaSize = aPlaceholderContainer->GetLogicalSize(pcWM);
+      LogicalMargin pcBorderPadding =
+        aPlaceholderContainer->GetLogicalUsedBorderAndPadding(pcWM);
+      alignAreaSize -= pcBorderPadding.Size(pcWM);
+    }
   } else if (parentType == nsGkAtoms::gridContainerFrame) {
     // This abspos elem's parent is a grid container. Per CSS Grid 10.1 & 10.2:
     //  - If the grid container *also* generates the abspos containing block (a
@@ -424,7 +440,7 @@ OffsetToAlignedStaticPos(const ReflowInput& aKidReflowInput,
     // the alignment container, too. (And its size is aAbsPosCBSize.)
     //  - Otherwise, we use the grid's padding box as the alignment container.
     // https://drafts.csswg.org/css-grid/#static-position
-    if (aPlaceholderContainer == aKidReflowInput.mCBReflowInput->mFrame) {
+    if (placeholderContainerIsContainingBlock) {
       // The alignment container is the grid area that we're using as the
       // absolute containing block.
       alignAreaSize = aAbsPosCBSize.ConvertTo(pcWM, aAbsPosCBWM);
diff --git a/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-001-ref.html b/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-001-ref.html
new file mode 100644
index 000000000..08eec8691
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-001-ref.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>

+<html><head>

+<meta http-equiv="content-type" content="text/html; charset=UTF-8"><title>CSS Test Reference</title>

+<meta charset="utf-8">

+<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">

+<style>

+.parent {

+  position: fixed;

+  top: 0;

+  left: 0;

+  display: block;

+  width: 200px;

+  height: 200px;

+  background: yellow;

+}

+

+.child {

+  position: absolute;

+  left: 50px;

+  top: 50px;

+  width: 100px;

+  height: 100px;

+  background: green;

+}

+</style>

+</head><body><div class="parent"><div class="child"></div></div>

+</body></html>
\ No newline at end of file
diff --git a/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-001.html b/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-001.html
new file mode 100644
index 000000000..5f623cb84
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-001.html
@@ -0,0 +1,30 @@
+<!DOCTYPE html>

+<html><head>

+<meta http-equiv="content-type" content="text/html; charset=UTF-8"><title>CSS Test: Absolutely positioned children of flex container with CSS align</title>

+<meta charset="utf-8">

+<link rel="help" href="https://drafts.csswg.org/css-flexbox/#abspos-items">

+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1386654">

+<link rel="match" href="https://hg.mozilla.org/mozilla-central/raw-file/6538de3b6137/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-001-ref.html">

+<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">

+<style>

+.parent {

+  position: fixed;

+  top: 0;

+  left: 0;

+  display: flex;

+  align-items: center;

+  justify-content: center;

+  width: 200px;

+  height: 200px;

+  background: yellow;

+}

+

+.child {

+  position: absolute;

+  width: 100px;

+  height: 100px;

+  background: green;

+}

+</style>

+</head><body><div class="parent"><div class="child"></div></div>

+</body></html>
\ No newline at end of file
diff --git a/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-002-ref.html b/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-002-ref.html
new file mode 100644
index 000000000..df730047b
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-002-ref.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>

+<html><head>

+<meta http-equiv="content-type" content="text/html; charset=UTF-8"><title>CSS Test Reference</title>

+<meta charset="utf-8">

+<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">

+<style>

+.parent {

+  position: fixed;

+  top: 0;

+  left: 0;

+  display: block;

+  width: 200px;

+  height: 200px;

+  background: yellow;

+}

+

+.child {

+  position: absolute;

+  left: 60px;

+  top: 60px;

+  width: 100px;

+  height: 100px;

+  background: green;

+}

+</style>

+</head><body><div class="parent"><div class="child"></div></div>

+</body></html>
\ No newline at end of file
diff --git a/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-002.html b/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-002.html
new file mode 100644
index 000000000..9e89c5ad0
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-002.html
@@ -0,0 +1,38 @@
+<!DOCTYPE html>

+<html><head>

+<meta http-equiv="content-type" content="text/html; charset=UTF-8"><title>CSS Test: Absolutely positioned children of flex container with CSS align</title>

+<meta charset="utf-8">

+<link rel="help" href="https://drafts.csswg.org/css-flexbox/#abspos-items">

+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1386654">

+<link rel="match" href="https://hg.mozilla.org/mozilla-central/raw-file/6538de3b6137/layout/reftests/w3c-css/submitted/flexbox/position-absolute-containing-block-002-ref.html">

+<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">

+<style>

+.parent {

+  position: fixed;

+  top: 0;

+  left: 0;

+  display: flex;

+  align-items: center;

+  justify-content: center;

+  width: 180px;

+  height: 180px;

+

+  /* Expand the background area to 200px, without touching the content-box,

+     which is what flex absolute children should be aligned relative to. */

+  border-top: 5px solid yellow;

+  padding-top: 15px;

+  border-left: 5px solid yellow;

+  padding-left: 15px;

+

+  background: yellow;

+}

+

+.child {

+  position: absolute;

+  width: 100px;

+  height: 100px;

+  background: green;

+}

+</style>

+</head><body><div class="parent"><div class="child"></div></div>

+</body></html>
\ No newline at end of file
diff --git a/layout/reftests/w3c-css/submitted/flexbox/reftest.list b/layout/reftests/w3c-css/submitted/flexbox/reftest.list
index fd8bfccc9..3df75aee6 100644
--- a/layout/reftests/w3c-css/submitted/flexbox/reftest.list
+++ b/layout/reftests/w3c-css/submitted/flexbox/reftest.list
@@ -211,3 +211,7 @@ fails == flexbox-min-height-auto-002b.html flexbox-min-height-auto-002-ref.html
 == flexbox-single-line-clamp-1.html flexbox-single-line-clamp-1-ref.html
 == flexbox-single-line-clamp-2.html flexbox-single-line-clamp-2-ref.html
 == flexbox-single-line-clamp-3.html flexbox-single-line-clamp-3-ref.html
+
+# Flexbox as an absolute containing block.
+== position-absolute-containing-block-001.html position-absolute-containing-block-001-ref.html
+== position-absolute-containing-block-002.html position-absolute-containing-block-002-ref.html
diff --git a/layout/style/Loader.cpp b/layout/style/Loader.cpp
index a1a0fcfd9..0ce337e29 100644
--- a/layout/style/Loader.cpp
+++ b/layout/style/Loader.cpp
@@ -1677,10 +1677,6 @@ Loader::LoadSheet(SheetLoadData* aLoadData,
 
   nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(channel));
   if (httpChannel) {
-    // Send a minimal Accept header for text/css
-    httpChannel->SetRequestHeader(NS_LITERAL_CSTRING("Accept"),
-                                  NS_LITERAL_CSTRING("text/css,*/*;q=0.1"),
-                                  false);
     nsCOMPtr<nsIURI> referrerURI = aLoadData->GetReferrerURI();
     if (referrerURI)
       httpChannel->SetReferrerWithPolicy(referrerURI,