When heights or sizes is empty, the layout should be fixed not responsive.

The AMP Runtime interprets an img with a height and width plus an empty heights
or sizes as layout=fixed. Currently the transformers and validator treat it as
layout=responsive.
PiperOrigin-RevId: 279189628

Author: honeybadgerdontcare

transformer/internal/htmlnode/htmlnode.go

@@ -131,6 +131,18 @@ func HasAttribute(n *html.Node, namespace, key string) bool {
 	return ok
 }
 
+// HasAttributeAndIsNotEmpty return true if the node has the attribute named
+// with 'key' and it's value is not empty.
+func HasAttributeAndIsNotEmpty(n *html.Node, namespace, key string) bool {
+	if v, ok := GetAttributeVal(n, namespace, key); ok {
+		if v != "" {
+			return true
+		}
+		return false
+	}
+	return false
+}
+
 // SetAttribute overrides the value of the attribute on node n with
 // namespace and key with val. If the attribute doesn't exist, it adds it.
 func SetAttribute(n *html.Node, namespace, key, val string) {

transformer/layout/layout.go

@@ -86,8 +86,8 @@ func ApplyLayout(n *html.Node) error {
 	}
 	actualLayout, err := getNormalizedLayout(
 		inputLayout, dimensions,
-		htmlnode.GetAttributeValOrNil(n, "", "sizes"),
-		htmlnode.GetAttributeValOrNil(n, "", "heights"))
+		htmlnode.HasAttributeAndIsNotEmpty(n, "", "sizes"),
+		htmlnode.HasAttributeAndIsNotEmpty(n, "", "heights"))
 	if err != nil {
 		return err
 	}
@@ -143,7 +143,7 @@ func getNormalizedDimensions(n *html.Node, layout amppb.AmpLayout_Layout) (cssDi
 
 // getNormalizedLayout returns the normalized AmpLayout based on the
 // provided dimensions, or an error if it is not supported.
-func getNormalizedLayout(layout amppb.AmpLayout_Layout, dimensions cssDimensions, sizes, heights *string) (amppb.AmpLayout_Layout, error) {
+func getNormalizedLayout(layout amppb.AmpLayout_Layout, dimensions cssDimensions, sizes, heights bool) (amppb.AmpLayout_Layout, error) {
 	var result amppb.AmpLayout_Layout
 	if layout != amppb.AmpLayout_UNKNOWN {
 		result = layout
@@ -153,7 +153,7 @@ func getNormalizedLayout(layout amppb.AmpLayout_Layout, dimensions cssDimensions
 		result = amppb.AmpLayout_FLUID
 	} else if dimensions.height.isSet && (!dimensions.width.isSet || dimensions.width.isAuto) {
 		result = amppb.AmpLayout_FIXED_HEIGHT
-	} else if dimensions.height.isSet && dimensions.width.isSet && (sizes != nil || heights != nil) {
+	} else if dimensions.height.isSet && dimensions.width.isSet && (sizes || heights) {
 		result = amppb.AmpLayout_RESPONSIVE
 	} else {
 		result = amppb.AmpLayout_FIXED

transformer/layout/layout_test.go

@@ -114,6 +114,20 @@ func TestApplyLayout(t *testing.T) {
 				html.Attribute{Key: "height", Val: "100"}, html.Attribute{Key: "layout", Val: "fixed-height"}),
 			`<amp-img height="100" layout="fixed-height" class="i-amphtml-layout-fixed-height i-amphtml-layout-size-defined" style="height:100px;" i-amphtml-layout="fixed-height"></amp-img>`,
 		},
+		{
+			"Fixed when heights is empty",
+			htmlnode.Element(
+				"amp-img",
+				html.Attribute{Key: "height", Val: "100"}, html.Attribute{Key: "heights", Val: ""}, html.Attribute{Key: "width", Val: "300"}),
+			`<amp-img height="100" heights="" width="300" class="i-amphtml-layout-fixed i-amphtml-layout-size-defined" style="width:300px;height:100px;" i-amphtml-layout="fixed"></amp-img>`,
+		},
+		{
+			"Fixed when sizes is empty",
+			htmlnode.Element(
+				"amp-img",
+				html.Attribute{Key: "height", Val: "100"}, html.Attribute{Key: "sizes", Val: ""}, html.Attribute{Key: "width", Val: "300"}),
+			`<amp-img height="100" sizes="" width="300" class="i-amphtml-layout-fixed i-amphtml-layout-size-defined" style="width:300px;height:100px;" i-amphtml-layout="fixed"></amp-img>`,
+		},
 		{
 			"Responsive",
 			htmlnode.Element(

transformer/transformers/serversiderendering.go

@@ -133,13 +133,13 @@ func canRemoveBoilerplate(n *html.Node) bool {
 		if n.Data == amphtml.AMPAudio {
 			return false
 		}
-		if htmlnode.HasAttribute(n, "", "heights") {
+		if htmlnode.HasAttributeAndIsNotEmpty(n, "", "heights") {
 			return false
 		}
-		if htmlnode.HasAttribute(n, "", "media") {
+		if htmlnode.HasAttributeAndIsNotEmpty(n, "", "media") {
 			return false
 		}
-		if htmlnode.HasAttribute(n, "", "sizes") {
+		if htmlnode.HasAttributeAndIsNotEmpty(n, "", "sizes") {
 			return false
 		}
 	}