fix memory leak (#837)

* fix memory leak

* Update install_darwin.go

* fix undefined symbol

* fix undefined symbol

* go fmt

certificates/install_darwin.go

@@ -66,6 +66,7 @@ import "C"
 import (
 	"errors"
 	"os/exec"
+	"unsafe"
 
 	log "github.com/sirupsen/logrus"
 
@@ -76,7 +77,9 @@ import (
 // if something goes wrong will show a dialog with the error and return an error
 func InstallCertificate(cert *paths.Path) error {
 	log.Infof("Installing certificate: %s", cert)
-	p := C.installCert(C.CString(cert.String()))
+	ccert := C.CString(cert.String())
+	defer C.free(unsafe.Pointer(ccert))
+	p := C.installCert(ccert)
 	s := C.GoString(p)
 	if len(s) != 0 {
 		oscmd := exec.Command("osascript", "-e", "display dialog \""+s+"\" buttons \"OK\" with title \"Error installing certificates\"")

systray/exec_darwin.go

@@ -48,6 +48,7 @@ import "C"
 import (
 	"os/exec"
 	"path/filepath"
+	"unsafe"
 
 	"github.com/sirupsen/logrus"
 )
@@ -67,7 +68,9 @@ func execApp(path string, args ...string) error {
 		C.setCharArray(argv, C.int(i), C.CString(arg))
 	}
 
-	C.runApplication(C.CString(path), argv, argc)
+	cpath := C.CString(path)
+	defer C.free(unsafe.Pointer(cpath))
+	C.runApplication(cpath, argv, argc)
 
 	C.freeCharArray(argv, argc)
 	return nil