Validate data before calling NetService.dictionary #86
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Decode the TXT record as a string dictionary, or [:] if the data is malformed: https://stackoverflow.com/a/52220739
Remove import
digaus
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digaus
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Thank you for hunting this down! What iOS versions have you tested this on? I'm not sure exactly how far back we need (or want) to support, but it would be good to know that it works on Any chance you have a link to the |
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Thanks for the fast response :) I tested it on 13.3 iPadOS and a user successfully tested on 13.3 iOS. Have no other devices on hand to do more testing. The code I use is from here: https://stackoverflow.com/a/52220739 Another solution would be to use the Objective C call: |
| var result = [String: String]() | ||
| var data = txtData | ||
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| while !data.isEmpty { |
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Is it possible to get stuck inside this while? If there is a timeout, how long does it take? We have to be aware of (and prevent if possible) long-running Cordova requests.
| case 2: | ||
| result[key] = String(keyValue[1]) | ||
| default: | ||
| fatalError() |
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How "fatal" is this - does it stackdump the entire application, or will Cordova pass this back as a failed promise? If it does dump, what do you think about catching and returning to Cordova with a failure message so the developer can handle it?
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| while !data.isEmpty { | ||
| // The first byte of each record is its length, so prefix that much data | ||
| let recordLength = Int(data.removeFirst()) |
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This is probably covered by the spec or data structure, but just in case: it's not possible for the length to be greater than one byte, right?
| let recordData = data[..<(data.startIndex + recordLength)] | ||
| data = data.dropFirst(recordLength) | ||
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| guard let record = String(bytes: recordData, encoding: .utf8) else { return [:] } |
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It looks like we now have 3 possible return values from this method:
- Empty key-value (
[:]) - Populated key, but empty value (
case 1: result[key] = "") - Populated key and value (
case 2: result[key] = String(keyValue[1]))
Previously I think if there were no records at all then the final JSON response looks like "txtRecord": {}. What does it look like now in the event that one of these guards returns [:]?
These guards might be a good spot to do some debug printing too.
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Valid questions but I cannot answer any of that, I have no experience in swift and just searched the issue until I found someone who ran into that aswell. You might find a better solution since we now know why the crash happens. I can do some testing on what responses I get for the 'textRecord'. Might also try this possible fix: https://stackoverflow.com/a/40473424 It only checks for correctness and then calls the initial method. |
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Tested, debugged, and approved. I'd like to add some text to the Thank you so much for helping us fix this! |
This prevents the crash of the app when a broadcast has the wrong format
#85
#79
#32