1 files changed, 25 insertions, 10 deletions
diff --git a/libgo/go/time/zoneinfo_ios.go b/libgo/go/time/zoneinfo_ios.go
index 6d7f975..f5a97be 100644
--- a/libgo/go/time/zoneinfo_ios.go
+++ b/libgo/go/time/zoneinfo_ios.go
@@ -7,22 +7,37 @@
 
 package time
 
-import "syscall"
+import (
+	"runtime"
+	"syscall"
+)
 
 var zoneSources = []string{
-	getZipParent() + "/zoneinfo.zip",
+	getZoneRoot() + "/zoneinfo.zip",
 }
 
-func getZipParent() string {
-	wd, err := syscall.Getwd()
-	if err != nil {
-		return "/XXXNOEXIST"
-	}
-
+func getZoneRoot() string {
 	// The working directory at initialization is the root of the
 	// app bundle: "/private/.../bundlename.app". That's where we
-	// keep zoneinfo.zip.
-	return wd
+	// keep zoneinfo.zip for tethered iOS builds.
+	// For self-hosted iOS builds, the zoneinfo.zip is in GOROOT.
+	roots := []string{runtime.GOROOT() + "/lib/time"}
+	wd, err := syscall.Getwd()
+	if err == nil {
+		roots = append(roots, wd)
+	}
+	for _, r := range roots {
+		var st syscall.Stat_t
+		fd, err := syscall.Open(r, syscall.O_RDONLY, 0)
+		if err != nil {
+			continue
+		}
+		defer syscall.Close(fd)
+		if err := syscall.Fstat(fd, &st); err == nil {
+			return r
+		}
+	}
+	return "/XXXNOEXIST"
 }
 
 func initLocal() {