Display widget signature

- but don't validate them for now;
  - Firefox will display a bar to warn that the signature validation is not supported (see https://bugzilla.mozilla.org/show_bug.cgi?id=854315)
  - almost all (all ?) pdf readers display signatures;
  - validation is done in edge but for now it's behind a pref.

test/pdfs/.gitignore

@@ -85,6 +85,7 @@
 !issue9458.pdf
 !issue9655_reduced.pdf
 !issue9915_reduced.pdf
+!bug854315.pdf
 !issue9940.pdf
 !issue10388_reduced.pdf
 !issue10438_reduced.pdf

test/test_manifest.json

@@ -389,6 +389,12 @@
        "rounds": 1,
        "type": "load"
     },
+    {  "id": "bug854315",
+       "file": "pdfs/bug854315.pdf",
+       "md5": "675754c07f71c068d2997905a5456f05",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "bug868745",
        "file": "pdfs/bug868745.pdf",
        "md5": "86111ea5097dd7daffcdea891ad1b348",

test/unit/api_spec.js

@@ -1212,6 +1212,7 @@ describe("api", function () {
           expect(info.IsAcroFormPresent).toEqual(false);
           expect(info.IsXFAPresent).toEqual(false);
           expect(info.IsCollectionPresent).toEqual(false);
+          expect(info.IsSignaturesPresent).toEqual(false);
 
           expect(metadata instanceof Metadata).toEqual(true);
           expect(metadata.get("dc:title")).toEqual("Basic API Test");
@@ -1254,6 +1255,7 @@ describe("api", function () {
           expect(info.IsAcroFormPresent).toEqual(false);
           expect(info.IsXFAPresent).toEqual(false);
           expect(info.IsCollectionPresent).toEqual(false);
+          expect(info.IsSignaturesPresent).toEqual(false);
 
           expect(metadata).toEqual(null);
           expect(contentDispositionFilename).toEqual(null);
@@ -1282,6 +1284,7 @@ describe("api", function () {
           expect(info.IsAcroFormPresent).toEqual(false);
           expect(info.IsXFAPresent).toEqual(false);
           expect(info.IsCollectionPresent).toEqual(false);
+          expect(info.IsSignaturesPresent).toEqual(false);
 
           expect(metadata).toEqual(null);
           expect(contentDispositionFilename).toEqual(null);

test/unit/document_spec.js

@@ -77,6 +77,7 @@ describe("document", function () {
       const pdfDocument = getDocument(null);
       expect(pdfDocument.formInfo).toEqual({
         hasAcroForm: false,
+        hasSignatures: false,
         hasXfa: false,
         hasFields: false,
       });
@@ -90,6 +91,7 @@ describe("document", function () {
       let pdfDocument = getDocument(acroForm);
       expect(pdfDocument.formInfo).toEqual({
         hasAcroForm: false,
+        hasSignatures: false,
         hasXfa: false,
         hasFields: false,
       });
@@ -98,6 +100,7 @@ describe("document", function () {
       pdfDocument = getDocument(acroForm);
       expect(pdfDocument.formInfo).toEqual({
         hasAcroForm: false,
+        hasSignatures: false,
         hasXfa: true,
         hasFields: false,
       });
@@ -106,6 +109,7 @@ describe("document", function () {
       pdfDocument = getDocument(acroForm);
       expect(pdfDocument.formInfo).toEqual({
         hasAcroForm: false,
+        hasSignatures: false,
         hasXfa: false,
         hasFields: false,
       });
@@ -114,6 +118,7 @@ describe("document", function () {
       pdfDocument = getDocument(acroForm);
       expect(pdfDocument.formInfo).toEqual({
         hasAcroForm: false,
+        hasSignatures: false,
         hasXfa: true,
         hasFields: false,
       });
@@ -127,6 +132,7 @@ describe("document", function () {
       let pdfDocument = getDocument(acroForm);
       expect(pdfDocument.formInfo).toEqual({
         hasAcroForm: false,
+        hasSignatures: false,
         hasXfa: false,
         hasFields: false,
       });
@@ -135,6 +141,7 @@ describe("document", function () {
       pdfDocument = getDocument(acroForm);
       expect(pdfDocument.formInfo).toEqual({
         hasAcroForm: true,
+        hasSignatures: false,
         hasXfa: false,
         hasFields: true,
       });
@@ -146,6 +153,7 @@ describe("document", function () {
       pdfDocument = getDocument(acroForm);
       expect(pdfDocument.formInfo).toEqual({
         hasAcroForm: true,
+        hasSignatures: false,
         hasXfa: false,
         hasFields: true,
       });
@@ -169,6 +177,7 @@ describe("document", function () {
       pdfDocument = getDocument(acroForm, xref);
       expect(pdfDocument.formInfo).toEqual({
         hasAcroForm: false,
+        hasSignatures: true,
         hasXfa: false,
         hasFields: true,
       });