Ensure that Lexer_getName does not fail if a Name contains in invalid usage of the NUMBER SIGN (#) (issue 6692)

*This is a regression from PR 3424.*

The PDF file in the referenced issue is using `Type3` fonts. In one of those, the `/CharProcs` dictionary contains an entry with the name `/#`. Before the changes to `Lexer_getName` in PR 3424, we were allowing certain invalid `Name` patterns containing the NUMBER SIGN (#).

It's unfortunate that this has been broken for close to two and a half years before the bug surfaced, but it should at least indicate that this is not a widespread issue.

Fixes 6692.

test/pdfs/issue6692.pdf.link

@@ -0,0 +1 @@
+http://web.archive.org/web/20151126121615/http://www.inf.ufg.br/~hugoribeiro/OSPs/osp-im.pdf

test/test_manifest.json

@@ -817,6 +817,15 @@
        "rounds": 1,
        "type": "eq"
     },
+    {  "id": "issue6692",
+       "file": "pdfs/issue6692.pdf",
+       "md5": "ba078e0ddd59cda4b6c51ea10599f49a",
+       "link": true,
+       "rounds": 1,
+       "firstPage": 11,
+       "lastPage": 11,
+       "type": "eq"
+    },
     {  "id": "devicen",
        "file": "pdfs/devicen.pdf",
        "md5": "aac6a91725435d1376c6ff492dc5cb75",

test/unit/parser_spec.js

@@ -1,4 +1,4 @@
-/* globals expect, it, describe, StringStream, Lexer, Linearization */
+/* globals expect, it, describe, StringStream, Lexer, Name, Linearization */
 
 'use strict';
 
@@ -77,6 +77,19 @@ describe('parser', function() {
 
       expect(result).toEqual('ABCD');
     });
+
+    it('should handle Names with invalid usage of NUMBER SIGN (#)', function() {
+      var inputNames = ['/# 680 0 R', '/#AQwerty', '/#A<</B'];
+      var expectedNames = ['#', '#AQwerty', '#A'];
+
+      for (var i = 0, ii = inputNames.length; i < ii; i++) {
+        var input = new StringStream(inputNames[i]);
+        var lexer = new Lexer(input);
+        var result = lexer.getName();
+
+        expect(result).toEqual(Name.get(expectedNames[i]));
+      }
+    });
   });
 
   describe('Linearization', function() {