Add secure libcurl transfer backend

tests/CMakeLists.txt

@@ -0,0 +1,3 @@
+add_executable(url_parse_test url_parse_test.c)
+target_link_libraries(url_parse_test PRIVATE prozilla)
+add_test(NAME url_parse COMMAND url_parse_test)

tests/url_parse_test.c

@@ -0,0 +1,28 @@
+#include <prozilla.h>
+#include <url.h>
+
+#include <stdio.h>
+
+static int check(const char *text, uerr_t protocol, unsigned short port)
+{
+  urlinfo url;
+  uerr_t result = proz_parse_url(text, &url, 0);
+
+  if (result != URLOK || url.proto != protocol || url.port != port)
+    {
+      fprintf(stderr, "failed to parse %s (result=%d protocol=%d port=%u)\n",
+              text, result, url.proto, url.port);
+      return 1;
+    }
+  proz_free_url(&url, 0);
+  return 0;
+}
+
+int main(void)
+{
+  return check("http://example.invalid/file", URLHTTP, 80)
+    || check("https://example.invalid/file", URLHTTPS, 443)
+    || check("ftp://example.invalid/file", URLFTP, 21)
+    || check("ftps://example.invalid/file", URLFTPS, 990)
+    || check("sftp://example.invalid/file", URLSFTP, 22);
+}