XFA - Remove empty pages

  - it aims to fix mozilla#13583;
  - because hidden subform and breakBefore some pages can be empty so remove them;
  - don't fail when there is horizontal overflow (except in lr-tb);
  - fix a typo in radial gradient first argument.

src/core/xfa/layout.js

@@ -266,7 +266,7 @@ function checkDimensions(node, space) {
   }
 
   const parent = node[$getParent]();
-  const attempt = (node[$extra] && node[$extra].attempt) || 0;
+  const attempt = (parent[$extra] && parent[$extra].attempt) || 0;
   switch (parent.layout) {
     case "lr-tb":
     case "rl-tb":
@@ -307,20 +307,13 @@ function checkDimensions(node, space) {
       }
       return true;
     case "position":
-      const [x, y, w, h] = getTransformedBBox(node);
-      const isWidthOk = node.w === "" || Math.round(w + x - space.width) <= 1;
-      const isHeightOk = node.h === "" || Math.round(h + y - space.height) <= 1;
-
-      if (isWidthOk && isHeightOk) {
+      const [, y, , h] = getTransformedBBox(node);
+      if (node.h === "" || Math.round(h + y - space.height) <= 1) {
         return true;
       }
 
       const area = node[$getTemplateRoot]()[$extra].currentContentArea;
-      if (isWidthOk) {
-        return h + y > area.h;
-      }
-
-      return w + x > area.w;
+      return h + y > area.h;
     case "rl-row":
     case "row":
     default:

src/core/xfa/template.js

@@ -2390,8 +2390,10 @@ class Field extends XFAObject {
 
     const caption = this.caption ? this.caption[$toHTML]().html : null;
     if (!caption) {
-      // Even if no caption this class will help to center the ui.
-      ui.attributes.class.push("xfaLeft");
+      if (ui.attributes.class) {
+        // Even if no caption this class will help to center the ui.
+        ui.attributes.class.push("xfaLeft");
+      }
       return HTMLResult.success(createWrapper(this, html), bbox);
     }
 
@@ -3753,7 +3755,7 @@ class Radial extends XFAObject {
       this.type === "toEdge"
         ? `${startColor},${endColor}`
         : `${endColor},${startColor}`;
-    return `radial-gradient(circle to center, ${colors})`;
+    return `radial-gradient(circle at center, ${colors})`;
   }
 }
 
@@ -4269,6 +4271,7 @@ class Subform extends XFAObject {
     }
 
     if (children.length === 0) {
+      delete this[$extra];
       return HTMLResult.EMPTY;
     }
 
@@ -4540,6 +4543,7 @@ class Template extends XFAObject {
 
     while (true) {
       if (!hasSomething) {
+        mainHtml.children.pop();
         // Nothing has been added in the previous page
         if (++hasSomethingCounter === MAX_EMPTY_PAGES) {
           warn("XFA - Something goes wrong: please file a bug.");

test/pdfs/xfa_dhl_shipment.pdf.link

@@ -0,0 +1 @@
+https://web.archive.org/web/20210621073147/https://www.dhl.com/content/dam/downloads/g0/express/emailship_page/globalpage/dhl_emailship_pdfclient_my_en.pdf

test/test_manifest.json

@@ -930,6 +930,14 @@
        "link": true,
        "type": "load"
     },
+    {  "id": "xfa_dhl_shipment",
+       "file": "pdfs/xfa_dhl_shipment.pdf",
+       "md5": "503ece429d69e7d626d6932a475fbe63",
+       "link": true,
+       "rounds": 1,
+       "enableXfa": true,
+       "type": "eq"
+    },
     {  "id": "xfa_bug1716047",
        "file": "pdfs/xfa_bug1716047.pdf",
        "md5": "2f524163bd8397f43d195090978c3b56",

test/unit/xfa_tohtml_spec.js

@@ -64,6 +64,12 @@ describe("XFAFactory", function () {
           <draw w="1pt" h="1pt"><value><text>foo</text></value></draw>
         </subform>
       </subform>
+      <subform name="third">
+        <breakBefore targetType="pageArea" startNew="1"/>
+        <subform>
+          <draw w="1pt" h="1pt"><value><text>bar</text></value></draw>
+        </subform>
+      </subform>
     </subform>
   </template>
   <xfa:datasets xmlns:xfa="http://www.xfa.org/schema/xfa-data/1.0/">