Misc. bug: URL query is parsed into the host when the URL has no path

Start with common/http.h and run the provided C++ reproduction to inspect common_http_parse_url() for query-only URLs. Check the affected callers in common/download.cpp, common/hf-cache.cpp, tools/cli/cli-client.cpp, and tools/server/server-cors-proxy.h. Done means the host and query/path are parsed correctly and the query reaches HTTP requests.

Name and Version

$ llama-server --version
version: 0.3.0-dev (build 10797, commit 235f4e8)

Operating systems

Linux

Which llama.cpp modules do you know to be affected?

llama-cli, llama-server, libllama (core library)

Command line

llama-cli -mu 'https://example.com/model.gguf?download=1'

Problem description & steps to reproduce

Description

common_http_parse_url() in common/http.h splits the authority from the path by searching for the first /:

auto slash_pos = rest.find('/');

RFC 3986 ends the authority at the first /, ? or #, so a URL that carries a query but no path never terminates the authority. For https://example.com?download=1 the parser produces:

host -> example.com?download=1
path -> /

Two things then go wrong in common_http_client(), which builds the httplib::Client out of parts.host: the connection is attempted against a hostname that cannot resolve, and the query string is dropped from the request even if it could.

This parser is shared, so the same failure reaches every HTTP caller in the tree:
common/download.cpp (-mu / --model-url and remote GGUF fetches), common/hf-cache.cpp,
tools/cli/cli-client.cpp, and the server CORS proxy in tools/server/server-cors-proxy.h.

Query-only URLs are ordinary and commonly machine-generated, signed download links, CDN cache-busting parameters, and ?download=1-style flags, so this is hit by real endpoints rather than only by malformed input.

Repro

#include "common/http.h"
#include <iostream>

int main() {
    const auto parts = common_http_parse_url("https://example.com?download=1");
    std::cout << "host=" << parts.host << " path=" << parts.path << '\n';
}

g++ -std=c++17 -I. -Ivendor -Ivendor/cpp-httplib repro.cpp vendor/cpp-httplib/httplib.cpp -pthread -o repro
./repro

First Bad Commit

The find('/') split has been present since common/http.h was introduced in #16373;

Relevant log output

expected host=example.com path=?download=1
actual host=example.com?download=1 path=/