Issue #1370 - Part 3: Implement `content` keyword for `flex-basis` property

Partially based on https://bugzilla.mozilla.org/show_bug.cgi?id=1105111

7 files changed, 26 insertions, 4 deletions

diff --git a/layout/style/nsCSSKeywordList.h b/layout/style/nsCSSKeywordList.h
index 2629127fae..7e661bc483 100644
--- a/layout/style/nsCSSKeywordList.h
+++ b/layout/style/nsCSSKeywordList.h
@@ -205,6 +205,7 @@ CSS_KEY(column, column)
 CSS_KEY(column-reverse, column_reverse)
 CSS_KEY(condensed, condensed)
 CSS_KEY(contain, contain)
+CSS_KEY(content, content)
 CSS_KEY(content-box, content_box)
 CSS_KEY(contents, contents)
 CSS_KEY(context-fill, context_fill)
diff --git a/layout/style/nsCSSParser.cpp b/layout/style/nsCSSParser.cpp
index 0899e4e4ee..b409bfed7e 100644
--- a/layout/style/nsCSSParser.cpp
+++ b/layout/style/nsCSSParser.cpp
@@ -8574,7 +8574,7 @@ CSSParserImpl::ParseFlex()
   // "a unitless zero that is not already preceded by two flex factors must be
   //  interpreted as a flex factor.
   if (ParseNonNegativeVariant(tmpVal, flexBasisVariantMask | VARIANT_NUMBER,
-                              nsCSSProps::kWidthKTable) != CSSParseResult::Ok) {
+                              nsCSSProps::kFlexBasisKTable) != CSSParseResult::Ok) {
     // First component was not a valid flex-basis or flex-grow value. Fail.
     return false;
   }
@@ -8623,7 +8623,7 @@ CSSParserImpl::ParseFlex()
     if (!wasFirstComponentFlexBasis) {
       CSSParseResult result =
         ParseNonNegativeVariant(tmpVal, flexBasisVariantMask,
-                                nsCSSProps::kWidthKTable);
+                                nsCSSProps::kFlexBasisKTable);
       if (result == CSSParseResult::Error) {
         return false;
       } else if (result == CSSParseResult::Ok) {
diff --git a/layout/style/nsCSSPropList.h b/layout/style/nsCSSPropList.h
index b51867f3ce..ae5de51e5a 100644
--- a/layout/style/nsCSSPropList.h
+++ b/layout/style/nsCSSPropList.h
@@ -1758,7 +1758,7 @@ CSS_PROP_POSITION(
     // its own code to parse each subproperty. It does not depend on the
     // longhand parsing defined here.
     VARIANT_AHKLP | VARIANT_CALC,
-    kWidthKTable,
+    kFlexBasisKTable,
     offsetof(nsStylePosition, mFlexBasis),
     eStyleAnimType_Coord)
 CSS_PROP_POSITION(
diff --git a/layout/style/nsCSSProps.cpp b/layout/style/nsCSSProps.cpp
index 7d4e008b45..e3cd802417 100644
--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -2261,6 +2261,20 @@ const KTableEntry nsCSSProps::kWidthKTable[] = {
   { eCSSKeyword_UNKNOWN, -1 }
 };
 
+// This must be the same as kWidthKTable, but just with 'content' added:
+const KTableEntry nsCSSProps::kFlexBasisKTable[] = {
+  { eCSSKeyword__moz_max_content, NS_STYLE_WIDTH_MAX_CONTENT },
+  { eCSSKeyword__moz_min_content, NS_STYLE_WIDTH_MIN_CONTENT },
+  { eCSSKeyword__moz_fit_content, NS_STYLE_WIDTH_FIT_CONTENT },
+  { eCSSKeyword__moz_available,   NS_STYLE_WIDTH_AVAILABLE },
+  { eCSSKeyword_content,          NS_STYLE_FLEX_BASIS_CONTENT },
+  { eCSSKeyword_UNKNOWN, -1 }
+};
+static_assert(ArrayLength(nsCSSProps::kFlexBasisKTable) ==
+              ArrayLength(nsCSSProps::kWidthKTable) + 1,
+              "kFlexBasisKTable should have the same entries as "
+              "kWidthKTable, plus one more for 'content'");
+
 const KTableEntry nsCSSProps::kWindowDraggingKTable[] = {
   { eCSSKeyword_default, StyleWindowDragging::Default },
   { eCSSKeyword_drag, StyleWindowDragging::Drag },
diff --git a/layout/style/nsCSSProps.h b/layout/style/nsCSSProps.h
index 7b8c56860c..cf7ffda78f 100644
--- a/layout/style/nsCSSProps.h
+++ b/layout/style/nsCSSProps.h
@@ -892,6 +892,7 @@ public:
   static const KTableEntry kVolumeKTable[];
   static const KTableEntry kWhitespaceKTable[];
   static const KTableEntry kWidthKTable[]; // also min-width, max-width
+  static const KTableEntry kFlexBasisKTable[];
   static const KTableEntry kWindowDraggingKTable[];
   static const KTableEntry kWindowShadowKTable[];
   static const KTableEntry kWordBreakKTable[];
diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
index eb56559d93..b3c4ccc148 100644
--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -4424,7 +4424,7 @@ nsComputedDOMStyle::DoGetFlexBasis()
   //   }
 
   SetValueToCoord(val, StylePosition()->mFlexBasis, true,
-                  nullptr, nsCSSProps::kWidthKTable);
+                  nullptr, nsCSSProps::kFlexBasisKTable);
   return val.forget();
 }
 
diff --git a/layout/style/nsStyleConsts.h b/layout/style/nsStyleConsts.h
index 8966932626..4d2043cc47 100644
--- a/layout/style/nsStyleConsts.h
+++ b/layout/style/nsStyleConsts.h
@@ -776,6 +776,12 @@ enum class StyleDisplay : uint8_t {
 #define NS_STYLE_WIDTH_MIN_CONTENT              1
 #define NS_STYLE_WIDTH_FIT_CONTENT              2
 #define NS_STYLE_WIDTH_AVAILABLE                3
+// The 'content' keyword is only valid for 'flex-basis' (not for 'width').
+// Since the 'flex-basis' property accepts exactly the same values as 'width',
+// this 'flex-basis'-specific enumerated value is listed alongside the
+// 'width' ones, to be sure we don't accidentally overload this numeric
+// value with two different meanings if new 'width' keywords are added.
+#define NS_STYLE_FLEX_BASIS_CONTENT             4
 
 // See nsStyleDisplay.mPosition
 #define NS_STYLE_POSITION_STATIC                0