Fix storing URLs without scheme (#72)

* Fix storing URLs without scheme

If secrets are stored without specifying a scheme
(https://), the keychain-helper would interpret the
hostname as _path_, causing lookup of secrets to fail.

This patch makes sure that a scheme is added (if missing).

If no scheme is specified, https:// is used as a default.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

* Have pre go1.8 compiler able to compile

Signed-off-by: Tibor Vass <teabee89@gmail.com>

* Fix URL parsing with port and no scheme

Signed-off-by: Nassim 'Nass' Eddequiouaq <eddequiouaq.nassim@gmail.com>

* Improve parseURL comment

Signed-off-by: Nassim 'Nass' Eddequiouaq <eddequiouaq.nassim@gmail.com>

osxkeychain/url_non_go18.go

@@ -0,0 +1,41 @@
+//+build !go1.8
+
+package osxkeychain
+
+import (
+	"net/url"
+	"strings"
+)
+
+func getHostname(u *url.URL) string {
+	return stripPort(u.Host)
+}
+
+func getPort(u *url.URL) string {
+	return portOnly(u.Host)
+}
+
+func stripPort(hostport string) string {
+	colon := strings.IndexByte(hostport, ':')
+	if colon == -1 {
+		return hostport
+	}
+	if i := strings.IndexByte(hostport, ']'); i != -1 {
+		return strings.TrimPrefix(hostport[:i], "[")
+	}
+	return hostport[:colon]
+}
+
+func portOnly(hostport string) string {
+	colon := strings.IndexByte(hostport, ':')
+	if colon == -1 {
+		return ""
+	}
+	if i := strings.Index(hostport, "]:"); i != -1 {
+		return hostport[i+len("]:"):]
+	}
+	if strings.Contains(hostport, "]") {
+		return ""
+	}
+	return hostport[colon+len(":"):]
+}