fix(fetch): parse multipart body up to the full boundary delimiter#5561
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arshsmith1 wants to merge 2 commits into
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fix(fetch): parse multipart body up to the full boundary delimiter#5561arshsmith1 wants to merge 2 commits into
arshsmith1 wants to merge 2 commits into
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Signed-off-by: arshiya tabasum <arshi@bugqore.com>
KhafraDev
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Jul 15, 2026
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| // The delimiter that terminates a part's body is the CRLF that precedes the | ||
| // next boundary delimiter line, i.e. "\r\n--boundary". Matching the full | ||
| // delimiter (not a bare boundary token) is required so boundary-like bytes | ||
| // inside a body are not mistaken for a delimiter. |
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| // The delimiter that terminates a part's body is the CRLF that precedes the | |
| // next boundary delimiter line, i.e. "\r\n--boundary". Matching the full | |
| // delimiter (not a bare boundary token) is required so boundary-like bytes | |
| // inside a body are not mistaken for a delimiter. |
| t.assert.strictEqual(form.get('fiŝo'), 'value1') | ||
| }) | ||
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| test('multipart formdata body containing the boundary token', async (t) => { |
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please move this to test/busboy
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Moved it to test/busboy/formdata-boundary-token.js.
Drop the explanatory comment on crlfDashBoundary and relocate the regression test out of client-fetch.js into test/busboy. Signed-off-by: arshiya tabasum <arshi@bugqore.com>
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This relates to...
Multipart parsing in
response.formData()/request.formData().Rationale
The body loop in
multipartFormDataParserlooked for a bare boundary token (boundary.subarray(2)) rather than the\r\n--boundarydelimiter line, then blindly subtracted 4 from the match index. A part whose body legitimately contains the boundary token gets truncated at the wrong offset, and in most cases the whole body is rejected withexpected CRLFeven though it is well framed. This block carried a// TODO: the steps here are completely wrongnote. The fix matches the full delimiter so boundary-like bytes inside a body are no longer mistaken for a delimiter, which also removes an ambiguity where such bytes could be read as an extra part.Changes
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\r\n--boundarywhen terminating a part body and slice up to that index, instead of finding the bare boundary token and offsetting by 4.Features
N/A
Bug Fixes
Breaking Changes and Deprecations
N/A
Status