Make second argument of UTF8ArrayToString optional. NFC #22696
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| * @param {number=} maxBytesToRead | ||
| * @return {string} | ||
| */`, | ||
| #if TEXTDECODER | ||
| $UTF8ArrayToString__deps: ['$UTF8Decoder'], | ||
| #endif | ||
| $UTF8ArrayToString: (heapOrArray, idx, maxBytesToRead) => { | ||
| $UTF8ArrayToString: (heapOrArray, idx = 0, maxBytesToRead = NaN) => { | ||
| #if CAN_ADDRESS_2GB | ||
| idx >>>= 0; | ||
| #endif |
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The comment on line 41 should replace "undefined" with "NaN"
| @@ -103,7 +103,7 @@ if (!isDataURI(wasmSourceMapFile)) { | |||
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| function getSourceMap() { | |||
| var buf = readBinary(wasmSourceMapFile); | |||
| return JSON.parse(UTF8ArrayToString(buf, 0, buf.length)); | |||
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Is this change NFC? Before we would read buf.length bytes at most, but after we read without limit until the end of a UTF8 string. But is wasmSourceMapFile guaranteed to be encoded that way (including a null terminator)?
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The third argument here is maxBytesToRead which means will read at most buf.length. However UTF8ArrayToString will always stop when it reads a null byte I believe
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But is there a null byte in this input? That is what concerns me. It is reading a source map file, which I don't think is encoded that way.
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Oh I assumed UTF8ArrayToString would not read read past the end of the input array! I don't see that check though. That's strange.
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Oh wait I think its fine because if you read of the end of a array or buffer in JS you get undefined back, so every buffer is effectively null terminated.
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Ah, good point. That looks safe then.
This is mostly a wash from a code size POV but makes the call sites more readable I think.
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This is mostly a wash from a code size POV but makes the call sites more readable I think.