From 2c8de242eeff532feb5258d4f150739d307d7e9f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlos=20Mart=C3=ADn=20Nieto?= <cmn@dwim.me>
Date: Wed, 26 Feb 2014 15:01:23 +0100
Subject: [PATCH] Allow for a default in reflog messages

We don't have a way to represent a NULL string, so if the user passes an
empty string, let's pass NULL down so we tell libgit2 to use the default.
---
 reference.go  | 27 +++++++++++++++++++++------
 repository.go | 18 ++++++++++++++----
 2 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/reference.go b/reference.go
index a2f1636..f7ea190 100644
--- a/reference.go
+++ b/reference.go
@@ -40,8 +40,13 @@ func (v *Reference) SetSymbolicTarget(target string, sig *Signature, msg string)
 	csig := sig.toC()
 	defer C.free(unsafe.Pointer(csig))
 
-	cmsg := C.CString(msg)
-	defer C.free(unsafe.Pointer(cmsg))
+	var cmsg *C.char
+	if msg == "" {
+		cmsg = nil
+	} else {
+		cmsg = C.CString(msg)
+		defer C.free(unsafe.Pointer(cmsg))
+	}
 
 	ret := C.git_reference_symbolic_set_target(&ptr, v.ptr, ctarget, csig, cmsg)
 	if ret < 0 {
@@ -60,8 +65,13 @@ func (v *Reference) SetTarget(target *Oid, sig *Signature, msg string) (*Referen
 	csig := sig.toC()
 	defer C.free(unsafe.Pointer(csig))
 
-	cmsg := C.CString(msg)
-	defer C.free(unsafe.Pointer(cmsg))
+	var cmsg *C.char
+	if msg == "" {
+		cmsg = nil
+	} else {
+		cmsg = C.CString(msg)
+		defer C.free(unsafe.Pointer(cmsg))
+	}
 
 	ret := C.git_reference_set_target(&ptr, v.ptr, target.toC(), csig, cmsg)
 	if ret < 0 {
@@ -93,8 +103,13 @@ func (v *Reference) Rename(name string, force bool, sig *Signature, msg string)
 	csig := sig.toC()
 	defer C.free(unsafe.Pointer(csig))
 
-	cmsg := C.CString(msg)
-	defer C.free(unsafe.Pointer(cmsg))
+	var cmsg *C.char
+	if msg == "" {
+		cmsg = nil
+	} else {
+		cmsg = C.CString(msg)
+		defer C.free(unsafe.Pointer(cmsg))
+	}
 
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()
diff --git a/repository.go b/repository.go
index 48c2b46..e4eaaed 100644
--- a/repository.go
+++ b/repository.go
@@ -153,8 +153,13 @@ func (v *Repository) CreateReference(name string, oid *Oid, force bool, sig *Sig
 	csig := sig.toC()
 	defer C.free(unsafe.Pointer(csig))
 
-	cmsg := C.CString(msg)
-	defer C.free(unsafe.Pointer(cmsg))
+	var cmsg *C.char
+	if msg == "" {
+		cmsg = nil
+	} else {
+		cmsg = C.CString(msg)
+		defer C.free(unsafe.Pointer(cmsg))
+	}
 
 	var ptr *C.git_reference
 
@@ -179,8 +184,13 @@ func (v *Repository) CreateSymbolicReference(name, target string, force bool, si
 	csig := sig.toC()
 	defer C.free(unsafe.Pointer(csig))
 
-	cmsg := C.CString(msg)
-	defer C.free(unsafe.Pointer(cmsg))
+	var cmsg *C.char
+	if msg == "" {
+		cmsg = nil
+	} else {
+		cmsg = C.CString(msg)
+		defer C.free(unsafe.Pointer(cmsg))
+	}
 
 	var ptr *C.git_reference
 
-- 
2.45.2