Fonts: check file signature before emitting warning in sandboxed env (plugin) #1080
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| do { | ||
| let values = try path.url.resourceValues(forKeys: [.typeIdentifierKey]) | ||
| guard let uti = values.typeIdentifier else { | ||
| return true |
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This is incorrect. If you can't get the typeIdentifier, it should fall back to reading the header bytes like you've done below.
I'd rework this do-catch into a simple if-else.
| } | ||
| return UTTypeConformsTo(uti as CFString, kUTTypeFont) | ||
| } catch { | ||
| if let data = try? Data(contentsOf: path.url), |
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This will load the whole file into memory, which is (or can be) slow. Instead, we should use FileHandle.read(upToCount:), with a maximum of N header bytes.
Note: best to create a constant for the amount of header bytes, just to make it clear.
| var isTrueTypeFont: Bool { | ||
| var values = [UInt8](repeating: 0, count:5) | ||
| self.copyBytes(to: &values, count: 5) | ||
| let firstBytesOfTTF: [UInt8] = [0x00, 0x01, 0x00, 0x00, 0x00] // https://en.wikipedia.org/wiki/List_of_file_signatures |
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These could be constants, like trueTypeFontHeaderBytes and such. And then a simple function on Path to check a file type given some header bytes.
Also avoids having a fixed "count" in the line above, as you can get the .count from the constant.
Fix for #1079 and #952
To prevent warning being displayed in Xcode when using the plugin, I've added a check for the signature of font files (the first bytes) before emitting the warning