[PDFBOX-3286] Think I found a bad constant (TTF) value and constant use in PDFBox source

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 2.0.1, 3.0.0 PDFBox
• Component/s: PDModel
• Environment: Found by source code inspection
• Assignee: Andreas Lehmkühler
• Reporter: Christophe Bouchon
• Created: 23/Mar/16 10:22
• Updated: 25/Mar/17 18:12
• Resolved: 25/Mar/16 16:45

Description

Was searching if an OBLIQUE constant was defined somewhere for fsSelection field of OS/2 TrueType table (org.apache.fontbox.ttf.OS2WindowsMetricsTable), found a private one in org.apache.pdfbox.pdmodel.font.TrueTypeEmbedder (line 53) in v2.0.0 but it was defined with value 256 instead of 512 (as defined in official Microsoft documentation here: https://www.microsoft.com/typography/otspec/os2.htm#fss, bits are defined starting at 0 and oblique is bit 9, so OBLIQUE should have value 512 (1 << 9) instead of 256. And the constant use (line 184), is wrong too, the line should be

        fd.setItalic((fsSelection & (ITALIC | OBLIQUE)) != 0);

instead of:

        fd.setItalic((fsSelection & ITALIC) == fsSelection ||
                     (fsSelection & OBLIQUE) == fsSelection);

because fsSelection can contain other bits set at the same time (like BOLD = 1 << 5), so the tests can be both false while one of the bit is set.