* fix(http): honor X-Forwarded-Prefix when proxy strips the prefix
Closes#9145.
Two related issues kept the React UI from loading when a reverse proxy
rewrites a sub-path with prefix-stripping (e.g. Caddy `handle_path`):
1. `BaseURL` only computed a prefix from the path StripPathPrefix had
removed, so when the proxy strips the prefix before forwarding, the
request arrives without it and the base URL was returned without a
prefix. Extract a `BasePathPrefix` helper and add an
`X-Forwarded-Prefix` header fallback so the prefix is recovered.
2. `<base href>` only changes how relative URLs resolve; the build
emits path-absolute references like `/assets/...` and
`/favicon.svg`, which still resolve against the origin and bypass
the proxy prefix. Rewrite those references in the served
`index.html` so the browser requests them through the proxy.
Adds unit coverage for `BaseURL` with a pre-stripped path and an
end-to-end test for the proxy-stripped scenario.
Assisted-by: Claude:claude-opus-4-7
* fix(http): gate X-Forwarded-Prefix through SafeForwardedPrefix in BasePathPrefix
BasePathPrefix consumed X-Forwarded-Prefix directly, so a value the
codebase elsewhere rejects (e.g. "//evil.com") slipped through and was
interpolated into the SPA index.html — both into the path-absolute asset
URL rewrite in serveIndex (turning "/assets/..." into "//evil.com/assets/...",
a protocol-relative URL that loads JS from a foreign origin) and into
<base href>. Route the header through the existing SafeForwardedPrefix
validator that StripPathPrefix and prefixRedirect already use, and
HTML-escape the prefix before injecting it into the asset rewrite as
defense in depth against attribute breakout.
Tests cover //evil.com, backslashes, control chars, CR/LF and a missing
leading slash; the integration test asserts an unsafe prefix can't poison
asset URLs.
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Assisted-by: claude-code:claude-opus-4-7-1m [Read] [Edit] [Bash]
---------
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: Ettore Di Giacinto <mudler@localai.io>
