Map all glyphs to the private use area and duplicate the first glyph.

There have been lots of problems with trying to map glyphs to their unicode
values. It's more reliable to just use the private use areas so the browser's
font renderer doesn't mess with the glyphs.

Using the private use area for all glyphs did highlight other issues that this
patch also had to fix:

  * small private use area - Previously, only the BMP private use area was used
    which can't map many glyphs. Now, the (much bigger) PUP 16 area can also be
    used.

  * glyph zero not shown - Browsers will not use the glyph from a font if it is
    glyph id = 0. This issue was less prevalent when we mapped to unicode values
    since the fallback font would be used. However, when using the private use
    area, the glyph would not be drawn at all. This is illustrated in one of the
    current test cases (issue #8234) where there's an "ä" glyph at position
    zero. The PDF looked like it rendered correctly, but it was actually not
    using the glyph from the font. To properly show the first glyph it is always
    duplicated and appended to the glyphs and the maps are adjusted.

  * supplementary characters - The private use area PUP 16 is 4 bytes, so
    String.fromCodePoint must be used where we previously used
    String.fromCharCode. This is actually an issue that should have been fixed
    regardless of this patch.

  * charset - Freetype fails to load fonts when the charset size doesn't match
    number of glyphs in the font. We now write out a fake charset with the
    correct length. This also brought up the issue that glyphs with seac/endchar
    should only ever write a standard charset, but we now write a custom one.
    To get around this the seac analysis is permanently enabled so those glyphs
    are instead always drawn as two glyphs.

test/pdfs/.gitignore

@@ -114,6 +114,7 @@
 !issue5686.pdf
 !issue3928.pdf
 !clippath.pdf
+!issue8795_reduced.pdf
 !close-path-bug.pdf
 !issue6019.pdf
 !issue6621.pdf
@@ -281,6 +282,7 @@
 !issue5475.pdf
 !annotation-border-styles.pdf
 !IdentityToUnicodeMap_charCodeOf.pdf
+!PDFJS-9279-reduced.pdf
 !issue5481.pdf
 !issue5567.pdf
 !issue5701.pdf
@@ -303,6 +305,7 @@
 !issue7014.pdf
 !issue8187.pdf
 !annotation-link-text-popup.pdf
+!issue9278.pdf
 !annotation-text-without-popup.pdf
 !annotation-underline.pdf
 !annotation-strikeout.pdf

test/pdfs/bug1425312.pdf.link

@@ -0,0 +1 @@
+https://web.archive.org/web/20171116124714/https://www.unicode.org/charts/PDF/U11A50.pdf

test/test_manifest.json

@@ -122,6 +122,12 @@
        "lastPage": 1,
        "type": "eq"
     },
+    {  "id": "issue8795_reduced",
+       "file": "pdfs/issue8795_reduced.pdf",
+       "md5": "3ce58fa4aff351d46c42e0677d582099",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "issue2391-1",
       "file": "pdfs/issue2391-1.pdf",
       "md5": "25ae9cb959612e7b343b55da63af2716",
@@ -2436,6 +2442,12 @@
        "link": false,
        "type": "text"
     },
+    {  "id": "issue9278",
+       "file": "pdfs/issue9278.pdf",
+       "md5": "9819c3a5715c1a46ea5a6740f9ead3da",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "bug894572",
        "file": "pdfs/bug894572.pdf",
        "md5": "e54a6b0451939f685ed37e3d46e16158",
@@ -3460,6 +3472,15 @@
       "rounds": 1,
       "type": "eq"
     },
+    {  "id": "bug1425312",
+       "file": "pdfs/bug1425312.pdf",
+       "md5": "5b1e7d3e4ba7792fab2b69d1836df5a9",
+       "link": true,
+       "rounds": 1,
+       "firstPage": 2,
+       "lastPage": 2,
+       "type": "eq"
+    },
     {  "id": "issue3438",
       "file": "pdfs/issue3438.pdf",
       "md5": "5aa3340b0920b65a377f697587668f89",
@@ -3699,6 +3720,12 @@
       "type": "eq",
       "about": "Image mask in higher resolution than the image itself"
     },
+    {  "id": "PDFJS-9279-reduced",
+       "file": "pdfs/PDFJS-9279-reduced.pdf",
+       "md5": "a562a25596e9fe571ac6fb5b9f561974",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "issue4436",
        "file": "pdfs/issue4436r.pdf",
        "md5": "4e43d692d213f56674fcac92110c7364",

test/unit/cff_parser_spec.js

@@ -14,7 +14,7 @@
  */
 
 import {
-  CFFCompiler, CFFParser, CFFStrings
+  CFFCompiler, CFFFDSelect, CFFParser, CFFStrings
 } from '../../src/core/cff_parser';
 import { SEAC_ANALYSIS_ENABLED } from '../../src/core/fonts';
 import { Stream } from '../../src/core/stream';
@@ -311,7 +311,7 @@ describe('CFFParser', function() {
     var fdSelect = parser.parseFDSelect(0, 2);
 
     expect(fdSelect.fdSelect).toEqual([0, 1]);
-    expect(fdSelect.raw).toEqual(bytes);
+    expect(fdSelect.format).toEqual(0);
   });
 
   it('parses fdselect format 3', function() {
@@ -327,7 +327,7 @@ describe('CFFParser', function() {
     var fdSelect = parser.parseFDSelect(0, 4);
 
     expect(fdSelect.fdSelect).toEqual([9, 9, 0xa, 0xa]);
-    expect(fdSelect.raw).toEqual(bytes);
+    expect(fdSelect.format).toEqual(3);
   });
 
   it('parses invalid fdselect format 3 (bug 1146106)', function() {
@@ -343,8 +343,7 @@ describe('CFFParser', function() {
     var fdSelect = parser.parseFDSelect(0, 4);
 
     expect(fdSelect.fdSelect).toEqual([9, 9, 0xa, 0xa]);
-    bytes[3] = bytes[4] = 0x00; // The adjusted first range, first gid.
-    expect(fdSelect.raw).toEqual(bytes);
+    expect(fdSelect.format).toEqual(3);
   });
 
   // TODO fdArray
@@ -400,5 +399,52 @@ describe('CFFCompiler', function() {
     expect(names[0].length).toEqual(127);
   });
 
+  it('compiles fdselect format 0', function() {
+    var fdSelect = new CFFFDSelect(0, [3, 2, 1]);
+    var c = new CFFCompiler();
+    var out = c.compileFDSelect(fdSelect);
+    expect(out).toEqual([
+      0, // format
+      3, // gid: 0 fd 3
+      2, // gid: 1 fd 3
+      1, // gid: 2 fd 3
+    ]);
+  });
+
+  it('compiles fdselect format 3', function() {
+    var fdSelect = new CFFFDSelect(3, [0, 0, 1, 1]);
+    var c = new CFFCompiler();
+    var out = c.compileFDSelect(fdSelect);
+    expect(out).toEqual([
+      3, // format
+      0, // nRanges (high)
+      2, // nRanges (low)
+      0, // range struct 0 - first (high)
+      0, // range struct 0 - first (low)
+      0, // range struct 0 - fd
+      0, // range struct 0 - first (high)
+      2, // range struct 0 - first (low)
+      1, // range struct 0 - fd
+      0, // sentinel (high)
+      4, // sentinel (low)
+    ]);
+  });
+
+  it('compiles fdselect format 3, single range', function() {
+    var fdSelect = new CFFFDSelect(3, [0, 0]);
+    var c = new CFFCompiler();
+    var out = c.compileFDSelect(fdSelect);
+    expect(out).toEqual([
+      3, // format
+      0, // nRanges (high)
+      1, // nRanges (low)
+      0, // range struct 0 - first (high)
+      0, // range struct 0 - first (low)
+      0, // range struct 0 - fd
+      0, // sentinel (high)
+      2, // sentinel (low)
+    ]);
+  });
+
   // TODO a lot more compiler tests
 });

test/unit/clitests.json

@@ -18,7 +18,6 @@
     "dom_utils_spec.js",
     "encodings_spec.js",
     "evaluator_spec.js",
-    "fonts_spec.js",
     "function_spec.js",
     "message_handler_spec.js",
     "metadata_spec.js",

test/unit/fonts_spec.js

@@ -1,91 +0,0 @@
-/* Copyright 2017 Mozilla Foundation
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import {
-  PRIVATE_USE_OFFSET_END, PRIVATE_USE_OFFSET_START, ProblematicCharRanges
-} from '../../src/core/fonts';
-
-/**
- * Used to validate the entries in `ProblematicCharRanges`, and to ensure that
- * its total number of characters does not exceed the PUA (Private Use Area)
- * length.
- * @returns {Object} An object with {number} `numChars`, {number} `puaLength`,
- *   and {number} `percentage` parameters.
- */
-var checkProblematicCharRanges = function checkProblematicCharRanges() {
-  function printRange(limits) {
-    return '[' + limits.lower.toString('16').toUpperCase() + ', ' +
-                  limits.upper.toString('16').toUpperCase() + ')';
-  }
-
-  var numRanges = ProblematicCharRanges.length;
-  if (numRanges % 2 !== 0) {
-    throw new Error('Char ranges must contain an even number of elements.');
-  }
-  var prevLimits, numChars = 0;
-  for (var i = 0; i < numRanges; i += 2) {
-    var limits = {
-      lower: ProblematicCharRanges[i],
-      upper: ProblematicCharRanges[i + 1],
-    };
-    if (!Number.isInteger(limits.lower) || !Number.isInteger(limits.upper)) {
-      throw new Error('Range endpoints must be integers: ' +
-                      printRange(limits));
-    }
-    if (limits.lower < 0 || limits.upper < 0) {
-      throw new Error('Range endpoints must be non-negative: ' +
-                      printRange(limits));
-    }
-    var range = limits.upper - limits.lower;
-    if (range < 1) {
-      throw new Error('Range must contain at least one element: ' +
-                      printRange(limits));
-    }
-    if (prevLimits) {
-      if (limits.lower < prevLimits.lower) {
-        throw new Error('Ranges must be sorted in ascending order: ' +
-                        printRange(limits) + ', ' + printRange(prevLimits));
-      }
-      if (limits.lower < prevLimits.upper) {
-        throw new Error('Ranges must not overlap: ' +
-                        printRange(limits) + ', ' + printRange(prevLimits));
-      }
-    }
-    prevLimits = {
-      lower: limits.lower,
-      upper: limits.upper,
-    };
-    // The current range is OK.
-    numChars += range;
-  }
-  var puaLength = (PRIVATE_USE_OFFSET_END + 1) - PRIVATE_USE_OFFSET_START;
-  if (numChars > puaLength) {
-    throw new Error('Total number of chars must not exceed the PUA length.');
-  }
-  return {
-    numChars,
-    puaLength,
-    percentage: 100 * (numChars / puaLength),
-  };
-};
-
-describe('Fonts', function() {
-  it('checkProblematicCharRanges', function() {
-    var EXPECTED_PERCENTAGE = 100;
-    var result = checkProblematicCharRanges();
-
-    expect(result.percentage).toBeLessThan(EXPECTED_PERCENTAGE);
-  });
-});

test/unit/jasmine-boot.js

@@ -60,7 +60,6 @@ function initializePDFJS(callback) {
     'pdfjs-test/unit/dom_utils_spec',
     'pdfjs-test/unit/encodings_spec',
     'pdfjs-test/unit/evaluator_spec',
-    'pdfjs-test/unit/fonts_spec',
     'pdfjs-test/unit/function_spec',
     'pdfjs-test/unit/message_handler_spec',
     'pdfjs-test/unit/metadata_spec',