remote: refactor proxy detection

Update the proxy detection for a remote.

1. Honor `http.<url>.proxy` syntax for a remote's direct URL and
   parent URLs.
2. Honor an empty configuration URL to override a proxy configuration.

Add tests to ensure that configuration specificity is honored.

1 files changed, 139 insertions, 0 deletions

diff --git a/tests/remote/httpproxy.c b/tests/remote/httpproxy.c
new file mode 100644
index 000000000..097db4cd5
--- /dev/null
+++ b/tests/remote/httpproxy.c
@@ -0,0 +1,139 @@
+#include "clar_libgit2.h"
+#include "remote.h"
+#include "net.h"
+
+static git_repository *repo;
+static git_net_url url = GIT_NET_URL_INIT;
+
+static int orig_proxies_need_reset = 0;
+static char *orig_http_proxy = NULL;
+static char *orig_https_proxy = NULL;
+static char *orig_no_proxy = NULL;
+
+void test_remote_httpproxy__initialize(void)
+{
+	git_remote *remote;
+
+	repo = cl_git_sandbox_init("testrepo");
+	cl_git_pass(git_remote_create(&remote, repo, "lg2", "https://github.com/libgit2/libgit2"));
+	cl_git_pass(git_net_url_parse(&url, "https://github.com/libgit2/libgit2"));
+
+	git_remote_free(remote);
+
+	orig_proxies_need_reset = 0;
+}
+
+void test_remote_httpproxy__cleanup(void)
+{
+	if (orig_proxies_need_reset) {
+		cl_setenv("HTTP_PROXY", orig_http_proxy);
+		cl_setenv("HTTPS_PROXY", orig_https_proxy);
+		cl_setenv("NO_PROXY", orig_no_proxy);
+
+		git__free(orig_http_proxy);
+		git__free(orig_https_proxy);
+		git__free(orig_no_proxy);
+	}
+
+	git_net_url_dispose(&url);
+	cl_git_sandbox_cleanup();
+}
+
+void assert_proxy_is(const char *expected)
+{
+	git_remote *remote;
+	char *proxy;
+
+	cl_git_pass(git_remote_lookup(&remote, repo, "lg2"));
+	cl_git_pass(git_remote__http_proxy(&proxy, remote, &url));
+
+	if (expected)
+		cl_assert_equal_s(proxy, expected);
+	else
+		cl_assert_equal_p(proxy, expected);
+
+	git_remote_free(remote);
+	git__free(proxy);
+}
+
+void assert_config_match(const char *config, const char *expected)
+{
+	git_remote *remote;
+	char *proxy;
+
+	if (config)
+		cl_repo_set_string(repo, config, expected);
+
+	cl_git_pass(git_remote_lookup(&remote, repo, "lg2"));
+	cl_git_pass(git_remote__http_proxy(&proxy, remote, &url));
+
+	if (expected)
+		cl_assert_equal_s(proxy, expected);
+	else
+		cl_assert_equal_p(proxy, expected);
+
+	git_remote_free(remote);
+	git__free(proxy);
+}
+
+void test_remote_httpproxy__config_overrides(void)
+{
+	/*
+	 * http.proxy should be honored, then http.<url>.proxy should
+	 * be honored in increasing specificity of the url.  finally,
+	 * remote.<name>.proxy is the most specific.
+	 */
+	assert_config_match(NULL, NULL);
+	assert_config_match("http.proxy", "http://localhost:1/");
+	assert_config_match("http.https://github.com.proxy", "http://localhost:2/");
+	assert_config_match("http.https://github.com/.proxy", "http://localhost:3/");
+	assert_config_match("http.https://github.com/libgit2.proxy", "http://localhost:4/");
+	assert_config_match("http.https://github.com/libgit2/.proxy", "http://localhost:5/");
+	assert_config_match("http.https://github.com/libgit2/libgit2.proxy", "http://localhost:6/");
+	assert_config_match("remote.lg2.proxy", "http://localhost:7/");
+}
+
+void test_remote_httpproxy__config_empty_overrides(void)
+{
+	/*
+	 * with greater specificity, an empty config entry overrides
+	 * a set one
+	 */
+	assert_config_match("http.proxy", "http://localhost:1/");
+	assert_config_match("http.https://github.com.proxy", "");
+	assert_config_match("http.https://github.com/libgit2/libgit2.proxy", "http://localhost:2/");
+	assert_config_match("remote.lg2.proxy", "");
+}
+
+void test_remote_httpproxy__env(void)
+{
+	orig_http_proxy = cl_getenv("HTTP_PROXY");
+	orig_https_proxy = cl_getenv("HTTPS_PROXY");
+	orig_no_proxy = cl_getenv("NO_PROXY");
+	orig_proxies_need_reset = 1;
+
+	/* HTTP proxy is ignored for HTTPS */
+	cl_setenv("HTTP_PROXY", "http://localhost:9/");
+	assert_proxy_is(NULL);
+
+	/* HTTPS proxy is honored for HTTPS */
+	cl_setenv("HTTPS_PROXY", "http://localhost:10/");
+	assert_proxy_is("http://localhost:10/");
+
+	/* NO_PROXY is honored */
+	cl_setenv("NO_PROXY", "github.com:443");
+	assert_proxy_is(NULL);
+
+	cl_setenv("NO_PROXY", "github.com:80");
+	assert_proxy_is("http://localhost:10/");
+
+	cl_setenv("NO_PROXY", "github.com");
+	assert_proxy_is(NULL);
+
+	cl_setenv("NO_PROXY", "github.dev,github.com,github.foo");
+	assert_proxy_is(NULL);
+
+	/* configuration overrides environment variables */
+	cl_setenv("NO_PROXY", "github.none");
+	assert_config_match("http.https://github.com.proxy", "http://localhost:11/");
+}