multipart/form-data broken on new firefox version #257

bobbbob98 · 2025-02-24T21:22:05Z

Multipart forms seem to be broken in new firefox versions, no idea why. It works in chromium, qtwebkit and firefox 128 ESR but it seems like something changed in a new version. I looked at the difference between the form format for between firefox versions but they seem the same. Here's a minimal example:

import prologue

const page = """<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
    <form action="/upload" method="post" enctype="multipart/form-data">
        <input type="file" name="image">
        <button type="submit">Upload</button>
    </form>
</body>
</html>"""

proc form(ctx: Context) {.async.} =
    resp htmlResponse(page)
    
proc upload(ctx: Context) {.async.} =
    try:
        let f = ctx.request.formParams["image"]
        if f.body.len == 0:
            resp "<h1>File upload is empty.</h1>"
        else:
            resp "<h1>Success, filename: " & f.params["filename"] & "</h1>"
    except KeyError:
        resp "<h1>Error, param 'image' not found.</h1>"

var app = newApp()
app.addRoute("/", form)
app.addRoute("/upload", upload, HttpPost)
app.run()

Will always respond with the error on firefox 135

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

multipart/form-data broken on new firefox version #257

multipart/form-data broken on new firefox version #257

bobbbob98 commented Feb 24, 2025

multipart/form-data broken on new firefox version #257

multipart/form-data broken on new firefox version #257

Comments

bobbbob98 commented Feb 24, 2025