Changeset 246461 in webkit

Timestamp:

Jun 15, 2019 7:11:37 AM (5 years ago)

Author:

Alan Bujtas

Message:

[LFC][MarginCollapsing] Add check for computed height value in MarginCollapse::marginsCollapseThrough
​https://bugs.webkit.org/show_bug.cgi?id=198883
<rdar://problem/51773395>

Reviewed by Antti Koivisto.

"A box's own margins collapse if... ...and it has a 'height' of either 0 or 'auto"
​https://www.w3.org/TR/CSS22/box.html#collapsing-margins

• layout/blockformatting/BlockMarginCollapse.cpp:

(WebCore::Layout::BlockFormattingContext::MarginCollapse::marginsCollapseThrough):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• layout/blockformatting/BlockMarginCollapse.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-06-15  Zalan Bujtas  <zalan@apple.com>
+
+        [LFC][MarginCollapsing] Add check for computed height value in MarginCollapse::marginsCollapseThrough
+        https://bugs.webkit.org/show_bug.cgi?id=198883
+        <rdar://problem/51773395>
+
+        Reviewed by Antti Koivisto.
+
+        "A box's own margins collapse if... ...and it has a 'height' of either 0 or 'auto"
+        https://www.w3.org/TR/CSS22/box.html#collapsing-margins
+
+        * layout/blockformatting/BlockMarginCollapse.cpp:
+        (WebCore::Layout::BlockFormattingContext::MarginCollapse::marginsCollapseThrough):
+
 2019-06-15  Zalan Bujtas  <zalan@apple.com>
 

trunk/Source/WebCore/layout/blockformatting/BlockMarginCollapse.cpp

@@ -385 +385 @@
         return false;
 
+    auto& style = layoutBox.style();
+    auto computedHeightValueIsZero = style.height().isFixed() && !style.height().value();
+    if (!(style.height().isAuto() || computedHeightValueIsZero))
+        return false;
+
     // FIXME: Check for computed 0 height.
-    if (!layoutBox.style().height().isAuto())
-        return false;
-
-    // FIXME: Check for computed 0 height.
-    if (!layoutBox.style().minHeight().isAuto())
+    if (!style.minHeight().isAuto())
         return false;