return text;

}

function isLikelyBase64Payload(value: string): boolean {

return /^[A-Za-z0-9+/=\r\n]+$/.test(value);

function canonicalizeInlineBase64Payload(value: string): string | undefined {

let cleaned = "";

let padding = 0;

let sawPadding = false;

for (let index = 0; index < value.length; index += 1) {

const code = value.charCodeAt(index);

if (code <= 0x20) {

continue;

}

if (code === 0x3d) {

padding += 1;

if (padding > 2) {

return undefined;

}

sawPadding = true;

cleaned += "=";

continue;

}

const isDataChar =

(code >= 0x41 && code <= 0x5a) ||

(code >= 0x61 && code <= 0x7a) ||

(code >= 0x30 && code <= 0x39) ||

code === 0x2b ||

code === 0x2f;

if (sawPadding || !isDataChar) {

return undefined;

}

cleaned += value[index];

}

return cleaned && cleaned.length % 4 === 0 ? cleaned : undefined;

}

function decodeDataImageWithLimits(

return { candidate: null, estimatedBytes: 0 };

}

const payload = match[3] ?? "";

if (!payload || !isLikelyBase64Payload(payload)) {

const canonicalPayload = canonicalizeInlineBase64Payload(payload);

if (!canonicalPayload) {

return { candidate: null, estimatedBytes: 0 };

}

const estimatedBytes = estimateBase64DecodedBytes(payload);

const estimatedBytes = estimateBase64DecodedBytes(canonicalPayload);

if (estimatedBytes <= 0) {

return { candidate: null, estimatedBytes: 0 };

}

}

try {

const data = Buffer.from(payload, "base64");

const data = Buffer.from(canonicalPayload, "base64");

return {

candidate: { kind: "data", data, contentType, placeholder: "<media:image>" },

estimatedBytes,