Sakurai/pdf.js
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Attempt to recover valid format 3 FDSelect data from broken CFF fonts (bug 1146106)

Browse Source 
According to the CFF specification, see http://partners.adobe.com/public/developer/en/font/5176.CFF.pdf#G3.46884, for `format 3` FDSelect data: "The first range must have a ‘first’ GID of 0".
Since the PDF file (attached in the bug) violates that part of the specification, this patch tries to recover valid FDSelect data to prevent OTS from rejecting the font.

Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1146106.
This commit is contained in:
Jonas Jenwald 2016-05-26 17:34:00 +02:00
parent bd47440e79
commit 6260fc09a3
5 changed files with 54 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
src/core/cff_parser.js
View File

@ -856,8 +856,8 @@ var CFFParser = (function CFFParserClosure() {
var start = pos;
var bytes = this.bytes;
var format = bytes[pos++];
var fdSelect = [];
var i;
var fdSelect = [], rawBytes;
var i, invalidFirstGID = false;
switch (format) {
case 0:
@ -865,11 +865,18 @@ var CFFParser = (function CFFParserClosure() {
var id = bytes[pos++];
fdSelect.push(id);
}
rawBytes = bytes.subarray(start, pos);
break;
case 3:
var rangesCount = (bytes[pos++] << 8) | bytes[pos++];
for (i = 0; i < rangesCount; ++i) {
var first = (bytes[pos++] << 8) | bytes[pos++];
if (i === 0 && first !== 0) {
warn('parseFDSelect: The first range must have a first GID of 0' +
' -- trying to recover.');
invalidFirstGID = true;
first = 0;
}
var fdIndex = bytes[pos++];
var next = (bytes[pos] << 8) | bytes[pos + 1];
for (var j = first; j < next; ++j) {
@ -878,13 +885,19 @@ var CFFParser = (function CFFParserClosure() {
}
// Advance past the sentinel(next).
pos += 2;
rawBytes = bytes.subarray(start, pos);
if (invalidFirstGID) {
rawBytes[3] = rawBytes[4] = 0; // Adjust the first range, first GID.
}
break;
default:
error('Unknown fdselect format ' + format);
error('parseFDSelect: Unknown format "' + format + '".');
break;
}
var end = pos;
return new CFFFDSelect(fdSelect, bytes.subarray(start, end));
assert(fdSelect.length === length, 'parseFDSelect: Invalid font data.');
return new CFFFDSelect(fdSelect, rawBytes);
}
};
return CFFParser;

1
test/pdfs/.gitignore vendored
View File

@ -37,6 +37,7 @@
!bug1050040.pdf
!bug1200096.pdf
!bug1068432.pdf
!bug1146106.pdf
!issue5564_reduced.pdf
!canvas.pdf
!bug1132849.pdf

BIN
test/pdfs/bug1146106.pdf Normal file
View File

Binary file not shown.

7
test/test_manifest.json
View File

@ -210,6 +210,13 @@
"link": false,
"type": "eq"
},
{ "id": "bug1146106",
"file": "pdfs/bug1146106.pdf",
"md5": "a323d3766da49ee40f7d5dff0aeb0cc1",
"rounds": 1,
"link": false,
"type": "eq"
},
{ "id": "issue1512",
"file": "pdfs/issue1512r.pdf",
"md5": "af48ede2658d99cca423147085c6609b",

35
test/unit/cff_parser_spec.js
View File

@ -262,10 +262,12 @@ describe('CFFParser', function() {
var bytes = new Uint8Array([0x00, // format
0x00, // gid: 0 fd: 0
0x01 // gid: 1 fd: 1
]);
parser.bytes = bytes;
]);
parser.bytes = bytes.slice();
var fdSelect = parser.parseFDSelect(0, 2);
expect(fdSelect.fdSelect).toEqual([0, 1]);
expect(fdSelect.raw).toEqual(bytes);
});
it('parses fdselect format 3', function() {
@ -273,13 +275,32 @@ describe('CFFParser', function() {
0x00, 0x02, // range count
0x00, 0x00, // first gid
0x09, // font dict 1 id
0x00, 0x02, // nex gid
0x0a, // font dict 2 gid
0x00, 0x02, // next gid
0x0a, // font dict 2 id
0x00, 0x04 // sentinel (last gid)
]);
parser.bytes = bytes;
var fdSelect = parser.parseFDSelect(0, 2);
]);
parser.bytes = bytes.slice();
var fdSelect = parser.parseFDSelect(0, 4);
expect(fdSelect.fdSelect).toEqual([9, 9, 0xa, 0xa]);
expect(fdSelect.raw).toEqual(bytes);
});
it('parses invalid fdselect format 3 (bug 1146106)', function() {
var bytes = new Uint8Array([0x03, // format
0x00, 0x02, // range count
0x00, 0x01, // first gid (invalid)
0x09, // font dict 1 id
0x00, 0x02, // next gid
0x0a, // font dict 2 id
0x00, 0x04 // sentinel (last gid)
]);
parser.bytes = bytes.slice();
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);
});
// TODO fdArray