From 8934a58f919a4d40d81c4ef055b7ee6d2f00fc93 Mon Sep 17 00:00:00 2001
From: Da Zheng <zhengda1936@gmail.com>
Date: Thu, 30 Jun 2016 17:49:44 -0400
Subject: [PATCH] [SAFS]: print err msgs when renaming fails.

---
 libsafs/native_file.cpp | 15 +++++++++++++++
 libsafs/native_file.h   |  9 +--------
 libsafs/safs_file.cpp   |  5 ++++-
 3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/libsafs/native_file.cpp b/libsafs/native_file.cpp
index de106b02..53567841 100644
--- a/libsafs/native_file.cpp
+++ b/libsafs/native_file.cpp
@@ -19,6 +19,8 @@
 
 #include <stddef.h>
 #include <assert.h>
+#include <errno.h>
+#include <string.h>
 
 #include "common.h"
 #include "native_file.h"
@@ -121,4 +123,17 @@ bool native_dir::delete_dir(bool recursive)
 	}
 }
 
+bool native_file::rename(const std::string &new_name)
+{
+	if (::rename(file_name.c_str(), new_name.c_str()) == 0) {
+		file_name = new_name;
+		return true;
+	}
+	else {
+		fprintf(stderr, "can't renmae to %s: %s\n", new_name.c_str(),
+				strerror(errno));
+		return false;
+	}
+}
+
 }
diff --git a/libsafs/native_file.h b/libsafs/native_file.h
index 84fabd4e..c87e00bc 100644
--- a/libsafs/native_file.h
+++ b/libsafs/native_file.h
@@ -90,14 +90,7 @@ class native_file
 		return file_name;
 	}
 
-	virtual bool rename(const std::string &new_name) {
-		if (::rename(file_name.c_str(), new_name.c_str()) == 0) {
-			file_name = new_name;
-			return true;
-		}
-		else
-			return false;
-	}
+	virtual bool rename(const std::string &new_name);
 
 	/**
 	 * Create/delete a file on the native file system.
diff --git a/libsafs/safs_file.cpp b/libsafs/safs_file.cpp
index 8b7ac475..a27f8d73 100644
--- a/libsafs/safs_file.cpp
+++ b/libsafs/safs_file.cpp
@@ -105,8 +105,11 @@ ssize_t safs_file::get_size() const
 
 bool safs_file::rename(const std::string &new_name)
 {
-	if (!exist())
+	if (!exist()) {
+		fprintf(stderr, "can't rename: the new name %s exists\n",
+				new_name.c_str());
 		return false;
+	}
 
 	for (unsigned i = 0; i < native_dirs.size(); i++) {
 		native_file f(native_dirs[i].get_file_name());