Use appearance stream to render locked annotations (bug 1723568)

src/core/annotation.js

@@ -471,6 +471,12 @@ class Annotation {
       this._streams.push(this.appearance);
     }
 
+    // The annotation cannot be changed (neither its position/visibility nor its
+    // contents), hence we can just display its appearance and don't generate
+    // a HTML element for it.
+    const isLocked = !!(this.flags & AnnotationFlag.LOCKED);
+    const isContentLocked = !!(this.flags & AnnotationFlag.LOCKEDCONTENTS);
+
     // Expose public properties using a data object.
     this.data = {
       annotationFlags: this.flags,
@@ -487,6 +493,7 @@ class Annotation {
       subtype: params.subtype,
       hasOwnCanvas: false,
       noRotate: !!(this.flags & AnnotationFlag.NOROTATE),
+      noHTML: isLocked && isContentLocked,
     };
 
     if (params.collectFields) {
@@ -1694,7 +1701,11 @@ class WidgetAnnotation extends Annotation {
   ) {
     // Do not render form elements on the canvas when interactive forms are
     // enabled. The display layer is responsible for rendering them instead.
-    if (renderForms && !(this instanceof SignatureWidgetAnnotation)) {
+    if (
+      renderForms &&
+      !(this instanceof SignatureWidgetAnnotation) &&
+      !this.data.noHTML
+    ) {
       return {
         opList: new OperatorList(),
         separateForm: true,

src/display/annotation_layer.js

@@ -2621,6 +2621,9 @@ class AnnotationLayer {
     let zIndex = 0;
 
     for (const data of annotations) {
+      if (data.noHTML) {
+        continue;
+      }
       if (data.annotationType !== AnnotationType.POPUP) {
         const { width, height } = getRectDims(data.rect);
         if (width <= 0 || height <= 0) {

test/pdfs/bug1723568.pdf.link

@@ -0,0 +1,2 @@
+https://bugzilla.mozilla.org/attachment.cgi?id=9234308
+

test/test_manifest.json

@@ -7421,5 +7421,14 @@
       "type": "eq",
       "annotations": true,
       "rotation": 270
+   },
+   {
+      "id": "bug1723568",
+      "file": "pdfs/bug1723568.pdf",
+      "md5": "c5cc9f1e01d195b96eadf8be0a819578",
+      "rounds": 1,
+      "link": true,
+      "type": "eq",
+      "forms": true
    }
 ]